MHS Boilers STRATA1, STRATA1 38, STRATA1 38 COMBI, STRATA1 46 COMBI Instructions Manual

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Page 1

STRATA1

38 & 38/46 COMBI

WALL MOUNTED, GAS FIRED,

ULTRA HIGH EFFICIENCY CONDENSING BOILERS

INSTRUCTIONS FOR INSTALLATION,

SERVICING & OPERATION OF

THE MODEL 38 BOILER & THE 38/46 COMBI

L 101

Page 2

STRATA1

38 & 38/46 COMBI

Index

page section

. . . . . . . . . . .

1.0

General Notes

. . . . . . . . . . .

2.0

Product Description

. . . . . . . . . . .

2.0

Product Description (contd)

. . . . . . . . . . .

3.0

Technical Data & Dimensions

. . . . . . . . . . .

4.0

Delivery Consignment/Unpacking The Boiler

. . . . . . . . . . . .

5.0

Boiler Location

. . . . . . . . . . . .

6.0

Installation Clearances

. . . . . . . . . . .

7.0

Wall Mounting

. . . . . . . . . . . .

8.0

Gas Connection

. . . . . . . . . . .

9.0

Water Connections

. . . . . . . . . . .

10.0

Condense Waste Connection

. . . . . . . . .

10.0

Condense Waste Connection (contd)

. . . . . . . . . . .

11.0

Flue Combustion Air Connection - General

. . . . . . . . .

12.0

Conventional Flue Installation

12-18

. . . . . . .

13.0

Room Sealed Flue Installations

. . . . . . . . .

14.0

Examples of Calculating Flue Pressure Loss

. . . . . . . . .

14.1

Calculating Flue Resistance

. . . . . . . . . . .

15.0

Flue Terminal Positions

. . . . . . . . .

15.0

Flue Terminal Positions (contd)

22-23

. . . . . . .

16.0

Ventilation Requirements Single Appliances

24-33

. . . . . . .

17.0

Hydraulic System Design (circuit diagrams)

. . . . . . . . .

17.1

Filling The System

. . . . . . . . . . .

17.2

Water Treatment System Cleaning

. . . . . . . . .

17.3

Care With The Use of Soldering Flux

. . . . . .17.4

Domestic Hot Water - Combi

. . . . . . . . . . .

17.5

Combi Boiler - Prevention of scale in

. . . . . . . . . . . . . . water to water heat exchanger

35-36

. . . . . . .

17.6

Combi Boiler Hot Water

. . . . . . . . . . . . . . System Pipework Pressure Drop

. . . . . . . . . . .

17.7

Combi Boiler - Domestic Hot Water

. . . . . . . . . . . . . . System Design Considerations

36-48

. . . . . . .

18.0

Electrical Connections

. . . . . . . . .

19.0

Commissioning The Strata 1 Boiler

. . . . . . . . . . .

19.1

Pre-Commissioning Checks

. . . . . . . . . . .

19.2

LPG Conversion Procedure

. . . . . . . . .

19.3

Control Panel

51-52

. . . . . . .

19.4

First Firing

52-54

. . . . . . .

19.5

Setting The Control Panel

54-60

. . . . . . .

19.6

Installer Programming of Control Panel

. . . . . . . . .

19.7

Output For Charging Hot Water

. . . . . . . . . . .

20.0

Setting The Boiler To Work

. . . . . . . . . . .

21.0

Servicing Instruction

. . . . . . . . . . .

21.1

Inspection

61-62

. . . . . . .

21.1

Inspection (contd)

. . . . . . . . . . .

21.2

Maintenance

. . . . . . . . .

21.2

Maintenance (contd)

63-65

. . . . . . .

22.0

Screen Display/Diagnosis Of Faults

65-66

. . . . . . .

22.1

(Possible) Causes Of Fault & Corrective Action

. . . . . . . . .

23.0

Instructing The User

. . . . . . . . . . .

23.1

To Turn on the Appliance

. . . . . . . . . . .

23.2

To Turn off the Appliance

68-70

. . . . . . .

24.0

Parts List

Page 3

STRATA1

38 & 38/46 COMBI

1.0 general

notes

These instructions are intended to assist the installer, commissioning engineer, maintenance engineer and user with the installation, maintenance and usage of the Strata 1-38 gas fired condensing boiler and the Strata 1-38/46 gas fired condensing combination boiler.

Please read this manual fully before commencing the installation of the appliance. The Strata 1 must only be installed by persons deemed to be competent i.e. Corgi Registered. This manual must be handed to the appliance user following completion of the installation. The appliance must not be left to operate with the outer casing removed.

conformity statement

Strata 1 38 & 38/46 Combi boilers are manufactured to the highest standard of quality, performance and safety, in accordance with EC standards. Strata 1 45, 60 & 75 boilers carry the CE mark

installation requirements

The installation of Strata 1 boilers must be in accordance with the relevant requirements of Gas Safety (Installation and Use) Regulations 1994, Health & Safety at Work Act, Building Regulations, I.E.E. Regulations, Construction (Design & Management) Regulations 1994, Local Authority Bye-Laws, Local and National Water Bye-Laws, Fire Authority Regulations and Insurance Company requirements.

The following Codes of Practice are also applicable:-

• BS6798: 1987 Specification for installation of gas fired hot water boilers of rated input not

exceeding 60kW.

• BS6880 Code of Practice for low temperature, hot water heating systems of output greater than

45kW. Parts 1, 2 and 3: 1988.

• CP342 Part 2: 1974 Code of Practice for centralised hot water supply.

• BS6644 1991 Specification for gas fired hot water boilers of rated inputs between 60kW and 2MW.

• IGE/UP/2 Gas installation pipework, boosters and compressors on industrial and commercial

premises.

• CIBSE Guide Reference sections B7, B11 and B13.

• BS5440 Installation of flues and ventilation for gas appliances of rated input not exceeding 60kW.

Part 1: 1990 Specification for the installation of flues.

• BS5440-2: 2000 Installation and maintenance of flues and ventilation for gas appliances of rated input

not exceeding 70kW net (1st, 2nd and 3rd family gases) Part 2: Specification for installation and

maintenance of ventilation for gas appliances.

• IGE/UP/10 Installation of gas appliances in industrial and commercial premises. Part 1: Flued appliances.

Page 4

STRATA1

38 & 38/46 COMBI

2.0 product

description

The Strata 1 range of wall mounted gas fired condensing boilers are state of the art appliances which

include a comprehensive range of features. The appliance must only be used on sealed and pressurised systems. System design must take into account the boiler operating ∆t of 20°C.

wall mounted with compact dimensions

At 900H x 458W x 355D, the Strata 1 boiler provides maximum heat from minimum dimensions

without compromising serviceability.

fully modulating heat output

The output of the boiler is fully variable, sliding between (approx.) 20% to 100%, which automatically and instantly adjusts to match the needs of the system. The percentage of power at any given time can be dictated by either outside air temperature, flow temperature, return temperature, stored or instantaneous domestic hot water temperature, or room temperature, or a combination of the aforementioned.

fully condensing stainless steel heat exchanger

The Strata 1 boiler is designed with extended heat exchange surface area and is fabricated from corrosion resistant long-life stainless steel. The unique Spiranox heat exchanger will return operating efficiencies from 88% gross (96% nett) at 60°C return temperature, up to 96% gross (104% nett), at 30°C return temperature.

extremely low harmful emissions

The boiler utilises 100% pre-mix gas/air fed at positive pressure to the metal fibre sheathed radiant burner. The combustion system incorporates internal flue gas re-circulation and this combined with the precise nature of pre-mix fuel/air control, gives ultra low emissions to satisfy the most stringent emission regulations in the world currently. That is: < 20mg/kWh NOx (14 ppm DAF) and < 14mg/kWh CO (13 ppm DAF). The fully modulating nature of the appliance also reduces emissions by avoiding repeated start/stops and the associated increase in emissions, which occurs with burner on/off cycling.

accurate variable burner output control

The pre-mix burner fan has a low voltage direct current drive motor with pulse relay counting. This system allows precise control over fan speed/combustion air volumes. Coupled with a gas valve system set to provide proportionately measured volumes of fuel to air, this allows extremely accurate and instant variable burner output control to be achieved.

high domestic hot water flow rate – combi boiler

The combi boiler includes a high performance water to water heat exchanger which coupled with a variable output up to 46kW provides up to 0.21 l/s of hot water raised through 50°C. The water to water heat exchanger contains 10 litres of primary water which is maintained at the required domestic hot water temperature so ensuring prompt delivery of hot water.

energy saving

In addition to the extremely efficient burner and heat exchanger system employed in the Strata 1, each appliance includes a modulating speed boiler primary pump.

This feature allows the boiler to self-maintain a 20°C ∆t across the heat exchanger, optimising the heat exchanger efficiency and reducing also the electrical consumption of the pump motor. The result is a seasonal increase in boiler efficiency of a further 7-10% and a reduction in pump electricity consumption of up to 70%.

Page 5

STRATA1

38 & 38/46 COMBI

2.0 product description (contd)

natural gas or LPG

Appliances can be supplied for use with natural gas (G20) or LPG (G31).

comprehensive microprocessor control

The boiler control panel includes a user friendly microprocessor control centre which manages the

entire function of the appliance and encompasses:-

1. Management of the essential safety functions of burner ignition and flame monitoring.

2. Water high temperature and flue gas high temperature safety cut out.

3. Modulation of the boiler output and pump speeds in conjunction with operating temperature control.

4. LCD display screen with two lines of text to continuously display operational or fault status.

5. In built weather compensator to provide direct-on boiler VT flow temperature (if required).

6. Remote stored hot water temperature control and when using optional temperature sensor gives the option of regular anti-legionella programme (not combi).

7. In built 2 stage boiler frost protection program.

8. In built pump exercising program to avoid standstill seizure.

9. Cold start boost facility.

10. PC compatibility with data logging which allows communication with the boiler via a lap-top computer to review/modify operational parameters and access operational history as an aid to fault finding and preventative maintenance.

11. Range rate adjustment which allows the power to be set to accurately match the maximum needs of the system, with the facility to set a different firing rate for heating. Output to hot water self adjusts to the heat transfer capability of the calorifier or the instantaneous demand (combi boiler).

12. Facility to connect optional matched control components which allow the boiler to control a heating circuit pump, *HWS primary pump or *diverter valve and an underfloor circuit mixing valve and pump, (MR03) plus the ability for the boiler to be controlled by a remote multi function modulating room unit. (RE2132) Multiple boilers may be connected to a modulating Kaskade manager (KKM2) or controlled via a 0-3 or 0-10v* signal (*via adaptor) which further enhances the operating efficiency of a larger load modular boiler system. (*Not combi).

13. Inbuilt time switch (3 on - 3 off/24hr) for heating control and *separate channel for hot water time control. (*Not combi).

room sealed option

If required, the boiler may be installed to be completely room sealed, taking combustion air directly

from outside the building, using a 125/80 concentric air duct/flue duct system. Inherent safety is afforded by the negative pressure within the boiler casing, which in the event of incorrect sealing results in safe inward air leakage only.

extended flue lengths

The excess fan pressure from the combustion system is 100 Pa, which allows the appliance to be

exhausted using small diameter PPS plastic flue components, over long distances, allowing for complete flexibility in boiler siting.

designed for ease of maintenance

Although compact, the Strata 1 does not compromise serviceability. The appliance has been engineered

to be easy to maintain with even the most major of service operations being able to be completed easily and quickly with the minimum of tools.

guarantee

The heat exchanger carries a five year guarantee against manufacturing or material defect. All other

parts carry a one year warranty against manufacturing or material defect.

Page 6

STRATA1

38 & 38/46 COMBI

3.0 technical data

& dimensions

Dimensions in millimetres

229

458

155

355

8109

110

950

front view

plan view

underside - 38/46 combi

145 145

100 100

38/46 Combi

DN125

DN80 22mm 22mm 22mm 22mm

/4" BSP-M

15mm

— —

DN125

DN80 22mm

— —

22mm

/4" BSP-M

15mm

— —

Connection Strata 1

1. Combustion Air Inlet

2. Flue Gas

3. Flow

4. Hot Water (Out)

5. Cold Water (In)

6. Return

7. Condense Waste Outlet

8. Gas Connection

9. Condense Syphon Cleaning Point

10. Glanded Cable Entries

Model Strata 1 Input Range Central Heating Net kW CH Modulating Output 80/60°CkW CH Modulating Output 50/30°CkW Min Working Pressure CH Bar Max Working Pressure CH Bar Max Flow Temperature CH °C Total Primary Capacity Litre Available CH Pump Pressure at

kPa

38kW & 20°C ∆t Input Range Domestic Hot Water Net

HW Modulating Output kW Domestic Hot Water Flow at 50° ∆t l/min Domestic Hot Water Flow at 35° ∆t l/m Max Working Pressure

Bar

Domestic HW Max Flue Gas Volume (Hot) m

Gas Consumption (Nat Gas G20) m

/h Min/Max Gas Inlet Pressure mbar Average Electrical Consumption Watts Power Supply V Weight Empty kg

38/46 Combi

6.4 - 36.0

6.2 - 34.6

7.0 - 37.8

0.5

3.0 85

12.4

23.5

6.4 - 46.0

13.14

18.77

10.0

65.13

0.68 - 4.77 18/60

230

6.4 - 36.0

6.2 - 34.6

7.0 - 37.8

0.5

3.0 85

2.4

32.5

6.4 - 46.0

— —

—

65.13

0.68 - 4.77 18/60

230

underside - model 38

100 100

145 145

10 3 10 8

Page 7

4.0 delivery consignment

/unpacking the boiler

The boiler is delivered as a consignment of a palleted carton containing the boiler and associated

fittings, plus any other optional ancillary flue or control components in separate cartons.

The boiler carton contains:-

● Assembled boiler.

● Wall mounting bracket.

● Fittings bag including: condense waste outlet hose union assembly, outside air temperature sensor c/w

wall fixings and 1/2" BSP inlet 3/4" BSP outlet safety pressure relief valve set 3 bar.

To unpack the boiler, the palleted carton should be laid on the floor. Carefully cut the nylon bands and lift away fibre board protective panel. Open carton top and lift out wall hanging bracket and fittings bag. Remove packing material and lift away bottomless carton. With 2 men, carefully lift boiler from palette by holding grey rear chassis only.

To remove the casing from the boiler, slacken the screw in the underside of the casing, unlatch left and right hand catches on underside of case, pull casing slightly to the front and lift upwards to disengage casing hooks from rear chassis and then remove casing to the front.

5.0 boiler

location

The Strata 1 Boiler is not suitable for installation external to a building. The position chosen for the boiler must be a structurally sound wall capable of supporting the weight of the boiler and any ancillaries. The position should allow for access to a condense waste drain nearby or an alternative is to install a condense sump receptacle and condense disposal pump which should remove the condense waste water to a remote drain. The wall mounting position of the boiler must allow the boiler to be true plumb vertical to ensure correct operation of the internal gravity flow condense system. The position for the boiler must satisfy the requirements of BS6798:1987 or BS6644:1991 as appropriate.

6.0 installation

clearances

For ease of installation, commissioning and maintenance the following minimum clearances should be observed:-

Sides 50mm Above 250mm Below 150mm Front 450mm

STRATA1

38 & 38/46 COMBI

Page 8

STRATA1

38 & 38/46 COMBI

7.0 wall

mounting

The Strata 1 boiler mounts to the wall via a wall mounting bracket which interlocks to a rail mounted upon the rear of the boiler. The wall mounting bracket should be firmly fixed to the wall using suitable fixings. The wall mounting bracket positioning detail is shown in fig 1. The boiler must be carefully offered up to the wall so that the rail on the rear of the boiler is just above the wall mounting bracket and then the boiler should be lowered to engage the bracket and rail. Lifting is advised with 2 persons. Do NO

T lift the boiler by the internal parts of the appliance.

Important Note

When viewed from the side, the north/south axis of the boiler must be vertical. The appliance must not be inclined out from the top, if necessary adjust the positioning of the boiler using the adjustable wall bearing assemblies located at the bottom rear left and right hand of the appliance back panel.

8.0 gas

connection

The gas connection is located at the base of the appliance rear centre, see fig 2.

The pipe size used to supply the appliance must not be smaller than the gas connection size on the appliance.

The connection to the appliance must include a suitable method of disconnection and a gas control cock must be installed adjacent to the appliance for isolation purposes.

The gas pipe used to supply the appliance must not allow a pressure drop of greater than 1mbar from the meter to the appliance.

The nominal inlet working gas pressure measured at the appliance should be

20.0 mbar for Nat Gas (G20) or 37 mbar for LPG (G31). The installer should install a pressure test point adjacent to the gas inlet connection.

Gas Connection

15mm

Fig 2.

Fig 1.

458

3 x ø 7.0

165

103

797 900

Page 9

Note the Strata 1 boiler must only be installed on sealed and pressurised systems. The maximum working pressure of the boiler = 3 bar. A safety valve set 3.0 bar is supplied with the boiler and must be installed onto the flow pipe adjacent to the boiler. It is recommended that the final working pressure (hot) of the system does not exceed 2.3 bar. Note – the appliance does NOT include an expansion vessel. A suitable vessel must be connected to the system.

The central heating flow and return connections are 22mm OD, located at the base of the appliance (see fig 3) and should be connected to the system pipework using compression type fittings. DO NOT make soldered connections onto the appliance.

The COMBI BOILER includes domestic hot and cold water connections located at the base of the appliance see fig 4. These connections are 22mm and should be connected using compression type fittings. DO NOT make soldered connections onto the appliance.

The flow, return and domestic cold supply pipework should include isolation valves and all pipes should include means of disconnection.

9.0 water

connections

10.0 condense

waste connection

The condense waste connection is located at the underside rear of the appliance see fig 5.

The condense syphon cleaning point is factory fitted with a heavy grade black plastic cap which MUST NOT BE REMOVED (see fig 5) apart from routine maintenance cleaning operations and must be in place whenever the appliance is in operation. WARNING operating the appliance with the cap removed from the syphon cleaning point will cause products of combustion to be discharged from the cleaning point.

The condense waste connection is a

/4" BSP Male threaded stub fabricated from

plastic. The installer must connect to this stub, a condense waste pipe fabricated from plastic tube and fittings (

/4", 22mm, overflow pipe is considered suitable).

Copper Tube is not acceptable. The condense waste pipe must fall continuously from the appliance to suitable nearby drain.

If any part of the condense waste pipe is to be run external to the building or is at risk of freezing, then the pipe must be suitably insulated to protect from freezing.

If a suitable drain for accepting the condense waste is not available nearby to, and below the boiler, (e.g. boiler installed in a basement below ground level location), then a suitable condense sump receptacle with a discharge pump should be installed below the boiler to remove the condense to a remote drain.

STRATA1

38 & 38/46 COMBI

Flow

22mm

Fig 3.

Fig 4.

Return 22mm

Cold Water Inlet 22mm Combi only

Hot Water

Outlet 22mm

Combi only

Page 10

STRATA1

38 & 38/46 COMBI

10.0 condense waste connection (contd)

Fig 5.

Condense Waste Connection

Syphon Cleaning

Point Must

Remain Capped

When making the condense waste pipe connection to the boiler, do not use adhesives, it is recommended to lightly apply a suitable jointing tape (PTFE or similar) and use only light pressure to connect fittings to the appliance to avoid damage to the condense waste outlet assembly.

It is recommended that the condense waste pipework should include a method of disconnection and cleaning points.

11.0 flue/combustion

air connection - general

The flue connection and combustion air inlet to the appliance are located on the top of the appliance see fig 6. These connections are arranged concentrically with the 80mm flue gas connection centrally within the 125mm air inlet connection.

There are two options for flueing the Strata 1 boiler:

i) Conventionally, using flue gas tube only and air for combustion from the room or compartment

in which the appliance is installed. If using a conventional flue arrangement then the room or

compartment must be ventilated in accordance

with the requirements of BS5440. For guidance

on ventilation see section 16.

ii) Room sealed using concentric 80/125

components or two seperate tubes, where air

for combustion is taken from outside of the

building. When using a room sealed flue, where

air for combustion is provided from outside of

the building directly to the appliance, ventilation

to a compartment may still be required - See

section 16 for general space cooling.

Multiple Boilers

For detail and advice on common flues serving multiple boilers, contact MHS Boilers Ltd.

Important Note

Where the Strata 1 is to be installed in an application where the combustion air is likely to be contaminated with oxidising agents, such as swimming pool areas, special industrial processes etc, then the appliance must be room sealed.

Air Inlet

Flue Gas Connection

Fig 6.

typical modular

flue arrangement

Inspection Area

Page 11

STRATA1

38 & 38/46 COMBI

12.0 conventional

flue installation

The Strata 1 boiler has an excess pressure combustion system, which coupled with the very low flue gas temperatures produced allows the appliance to exhausted over considerable distances using 80mm Polypropylene PPS flue pipe and fittings. Suitable flue pipe and fittings are available from MHS Boilers Ltd and are listed below.

The flue should be installed to have at least a 3° fall to the boiler to allow any condense formed in the flue to run back to the boiler.

The flue system used must be gas and water tight and must be adequately supported over it’s entire length. Support at 1 metre intervals. It is not necessary to install a terminal to the flue system, however, a mesh guard should be included to prevent blockage or entry of foreign material. Straight lengths may be cut to size with any surplus cut from the plain end. Tube ends should be cut square and de-burred.

Care should be taken when selecting a position for a low level discharge or discharge adjacent to windows etc as the flue terminal will plume heavily and the white water vapour discharge may cause a visual nuisance.

Flue components available from MHS Boilers Ltd

80 mm PPS Flue Tube x 1000 mm long (effective length 945 mm) 80 mm PPS Flue Bend x 93° 80 mm PPS Flue Bend x 45° 80 mm Wall Fixing Bracket - Aluminium 80 mm Bird Mesh Cap - Plated Steel

The above flue components are light grey self coloured Polypropylene moulded components with push together spigot and socket joints with integral seal ring located in the socket.

If fire stop seals are required to be installed where PPS plastic flue components pass through walls, floors or ceilings then suitable fire stop seals are available from:-

Nullifire Ltd Torrington Avenue Coventry CV4 9TJ

Tel 02476 855000 Fax 02476 469547

Dufaylite Developments Ltd Cromwell Road, St Neots Huntingdon PE19 1QW

Tel 01480 215000 Fax 01480 405526

Quelfire PO Box 35, Altrincham Cheshire WA14 5QA Tel 0161 928 7308

1000 mm

Effective Length 945mm

137

125

ø80

100

150

80 ø PPS Flue Tube x 1000 long

80 ø PPS Flue Bend x 93º

80 ø PPS Flue Bend x 45º

80 ø Wall Fixing Bracket

ø5 Woodscrew fitting

100 mm PPS Flue Tube x 1000 Long (Effective Length 945 mm) 100 mm PPS Flue Bend x 93° 100 mm PPS Flue Bend x 45° 100 mm Wall Fixing Bracket 100 mm Bird Mesh Cap - Plated Steel 80 x 100 mm Increaser

80 ø PPS flue components

100 ID

150

80 x 100 PPS Increaser

End Slip

Page 12

STRATA1

38 & 38/46 COMBI

13.0 room sealed

flue installations

The Strata 1 boiler has an excess pressure combustion system, which coupled with the very low flue gas temperatures produced allows the appliance to be exhausted and supplied with room sealed combustion air using a concentric flue arrangement of 80 mm PPS polypropylene flue pipe within a 125 mm outer painted metal air tube over considerable distances. A range of concentric flue components are available from MHS Boilers Ltd and are listed below. Alternatively, two seperate tubes, one carrying combustion air and one carrying flue gas may be used in conjunction with the appropriate adaptor.

The concentric flue system should be installed to have at least a 3° fall to the boiler to allow any condense formed in the flue to run back to the boiler.

The flue system must be gas and water tight and must be adequately supported over it’s entire length. Support at 1.5m intervals. Horizontal Discharge and Vertical Discharge Terminal Sets are available.

Concentric flue components have push together spigot and socket joints. Both the inner PPs flue gas tube and the outer air tube have soft seal rings located in the socket components.

To aid assembly and assurance that the joints have been fully pushed home, the seal rings and make ends of tubes/fittings should be lightly lubricated with silicone grease.

list of concentric flue components

● 80/125 concentric wall terminal set:- comprises 845 mm straight length with made on terminal, 90°

concentric bend and wall bezel plates.

● 80/125 concentric roof terminal set:- comprises 1000 mm straight length with made on terminal and

1Nr 125 wall bracket.

● 125 pitched roof tile flashing for use with concentric roof terminal set, adjustable between 25° to 50°.

● 125 flat roof flashing for use with concentric roof terminal set.

● 80/125 concentric flue tube set x 1000 mm.

● 80/125 concentric flue tube set x 500 mm.

● 80/125 concentric 93° bend.

● 80/125 concentric 45° bend.

● 125 Wall bracket assembly.

● 80/125 concentric vertically extendible discharge room sealed wall terminal assembly (610 mm long

(*850) - For use where a standard wall terminal may cause visual flue gas pluming nuisance. Includes 90°

Concentric bend, wall bezel plates and silicone mastic. Used in conjunction with additional 80 mm pps

flue gas tube and fittings listed on page 10.

● 80/125 concentric to 2 x 80 mm separate tubes adaptor.

● 80/125 to 100/150 concentric increaser (not shown).

● 100/150 concentric wall terminal (not shown).

● 100/150 concentric roof terminal (not shown).

● 100/150 concentric flue tube set x 1000 mm (not shown).

● 100/150 concentric flue tube set x 500 mm (not shown).

● 100/150 concentric 93°C bend (not shown).

● 100/150 concentric 45°C bend (not shown).

Page 13

STRATA1

38 & 38/46 COMBI

13.0 room sealed flue installations (contd)

497

1000

Effective Length 950 mm

994

Effective Length 450mm

125

110

178

ø 7mm "Drive In" Fixing C/W Wall Plug

125

110

125

93º

80/125 Concentric Tube x 500mm

80/125 Concentric Bend x 45º

ø125 Wall Fixing Bracket

80/125 Concentric Tube x 1000mm

80/125 Concentric bend x 93º

491

80/125 concentric roof terminal & accessories

80/125 Concentric Roof Terminal Assembly

125

1170

513 513

130

390

500

Circular 125 Spun Aluminium Flat Roof Flashing

Pitched Roof Flashing - Adjustable 25-38º & 37-50º

125 Pitched Roof Adjustable Flashing. Adjustable between 25-38º and 37-50º

Lead Apron 1.3mm

458

229

355178900

155

120

80 80

plan

80/125 Concentric to 2 x 80 mm Tubes Adaptor

Flue Gas

Air for

Combustion

Page 14

STRATA1

38 & 38/46 COMBI

13.0 room sealed flue installations (contd)

installation of standard wall terminal

In order to determine the length of concentric tube required to correctly terminate a side outlet arrangement, the following procedure should be followed:

1. Measure wall thickness W in mm - see fig 7.

2. Measure distance between side of appliance and inside face of wall L1 in mm see fig 7.

3. Mark off and cut flue tubes following guidance shown in fig 8 below. Flue tubes should be cut to length

TL in mm. Both inner and outer tubes should be cut flush with each other, square and any

burrs removed.

Where TL required, is greater than 845 mm, then additional lengths (as appropriate) of 80/125 concentric tube will be required to extend the standard wall terminal. A fall of 3˚ is required along the length of the flue towards the appliance.

detail for marking out for

cutting flue hole for side flue,

room sealed horizontal

arrangement

Cut Flue Hole ø 130mm

Line-Top of

Appliance C

hassis

155

170

side outlet

170

Plain Section Installed Uppermost

Wall Bezel Plates

Required Length Cutting Line

measure from this point

TL (mm)

TL = W+L1+235mm

concentric wall terminals

945

610

850*

845

Standard Horizontal Discharge Wall Terminal (supplied with 80/125 Concentric 90º bend and wall bezel plates not shown)

Horizontal Wall Terminal With Extendible Vertical Discharge (supplied with 80/125 Concentric 90º bend and wall bezel plates not shown)

ø125

ø80

ø125

ø80

Fig 7.

Fig 8.

Fig 9.

side outlet

˚ fall to

appliance)

Page 15

STRATA1

38 & 38/46 COMBI

installation of standard wall terminal

In order to determine the length of concentric tube required to correctly terminate a rear outlet

arrangement, the following procedure should be followed.

1. Measure wall thickness W in mm - see fig 10.

2. Mark off and cut flue tubes following guidance shown in fig 11 below.

Flue tubes should be cut to length TL in mm. Both inner and outer tubes should be cut flush with each

other, square and any burrs removed.

13.0 room sealed flue installations (contd)

rear outlet rear outlet

170

Plain Section Installed Uppermost

Wall Bezel Plates

Required Length Cutting Line

measure from this point

TL (mm)

TL = W+161mm

170

cut flue hole ø130

detail for marking out for cutting flue hole for rear flue, room sealed horizontal arrangement

Fig 10. Fig 11.

Fig 12.

Page 16

STRATA1

38 & 38/46 COMBI

method of assembly of horizontal concentric flue system using standard wall terminal

1. Lubricate male ends of concentric bend with silicone grease and locate bend into flue and air tube connection sockets on the top of the boiler and gently push fully home.

2. Slip flue tube and terminal assembly through prepared hole in the outside wall.

3. Locate wall bezel plate loosely onto air tube.

4. Lubricate male ends of concentric flue tube and female sockets of flue bend lightly with silicone grease. Insert concentric tubes into bend and gently push fully home. Ensure plain section of external part of air inlet tube is located uppermost.

5. Make good internally and externally gap between air tube and prepared hole through wall.

6. Slip on external wall bezel plate.

7. Fix internal and external wall bezel plates with fixings provided.

Where a flue terminal discharges through a wall within 2m of ground level or balcony etc then

the terminal should be fitted with an appropriate sized terminal guard to prevent that the terminal may be touched.

extending the flue gas discharge vertically away from a room sealed wall terminal

The Strata 1 boiler is a fully condensing appliance with very low flue gas temperatures. Consequently,

the flue gas discharge is commonly seen as a white vapour plume, Whereas this is not harmful when properly discharged into the atmosphere outside of a building from a correctly operating appliance, the white vapour plume may cause, in certain applications a visual nuisance.

It must also be considered that a flue termination will drip condense water and may cause an ice hazard

below the terminal position

If it is considered that pluming or dripping from the end of a standard wall terminal may create a

nuisance, then as an alternative, the vertically extendible discharge wall terminal is available see figs 14 and

16. This creates a local room sealed intake for combustion air but allows the installer to extend the 80 mm

PPS flue gas tube to a point where pluming or dripping discharge will not cause a visual nuisance or hazard.

installation of vertical discharge wall terminal

In order to determine the length of concentric tube required to correctly terminate a side outlet

extended vertical discharge arrangement, the following procedure should be followed.

1. Measure wall thickness W in mm - see fig 14 overleaf.

2. Measure distance between side of appliance and inside face of wall L1 in mm - see fig 14 overleaf.

3. Mark off and cut flue tubes following guidance shown in fig 15 overleaf. Flue tubes should be cut to length TL in mm. Both inner and outer tubes should be cut flush with each other, square and any burrs removed.

Where TL required, is greater than 610 mm, (*850mm) then additional lengths (as appropriate) of

80/125 concentric tube will be required to extend the vertical discharge wall terminal. A fall of 3˚ is required along the length of the flue towards the appliance.

13.0 room sealed flue installations (contd)

Plain Section Uppermost

Fig 13.

Page 17

STRATA1

38 & 38/46 COMBI

installation of vertical discharge wall terminal with rear outlet

In order to determine the length of concentric tube required to correctly terminate a rear outlet

extended vertical discharge arrangement, the following procedure should be followed.

1. Measure wall thickness W in mm - see fig 16.

2. Mark off and cut flue tubes following guidance shown in fig 17 below.

Flue tubes should be cut to length TL in mm. Both inner and outer tubes should be cut flush with each

other, square and any burrs removed.

Where TL required is greater than 610 mm, (*850) then additional lengths (as appropriate) of 80/125 Concentric tube will be required to extend the vertical discharge wall terminal. A fall of 3˚ is required along the length of the flue towards the appliance.

installation of vertical discharge wall terminal with side outlet

170

ø80 PPS 90º Bend

ø80 Bird Mesh

ø80 PPS Tube

Exhaust Outlet Installed vertically Upwards on same wall aspect

Wall Bezel Plates

Required Length Cutting Line

measure from this point

TL (mm)

TL = W+262mm

side outlet

170

ø80 PPS 90º Bend

ø80 Bird Mesh

ø80 PPS Tube

Exhaust Outlet Installed vertically Upwards on same wall aspect

Wall Bezel Plates

Required Length Cutting Line

measure from this point

TL (mm)

TL = W+L1+260mm

Fig 14. Fig 15.

side outlet

rear outlet rear outlet

Fig 16.

Fig 17.

13.0 room sealed flue installations (contd)

Page 18

STRATA1

38 & 38/46 COMBI

method of assembly of extendible vertical discharge wall terminal assembly

See fig 18.

1. Lubricate male ends of concentric bend with silicone grease and locate bend into flue and air tube connection sockets on the top of the boiler and gently push fully home.

2. Slip flue tube and terminal assembly through prepared hole in the outside wall.

3. Locate internal wall bezel plate loosely onto air tube.

4. Lubricate male ends of concentric flue tubes and female sockets of flue bend lightly with silicone grease. Insert concentric tubes into bend and gently push fully home. Ensure flue gas discharge is positioned vertically upwards.

5. Made good internally and externally gap between air tube and prepared hole through wall.

6. Fit external 2 piece wall bezel and secure both internal and external wall bezels using fixings provided.

7. Seal air tube to exhaust discharge with a bead of silicone rubber mastic (mastic supplied) to create

weather seal to avoid entry of rain water into air tube.

8. Extend flue gas discharge to chosen position using 80 mm PPS flue tube fittings. Flue gas discharge must discharge on same face of building as air inlet to avoid wind caused imbalance in flue system.

Extend using 80ø

PPS tube

Flue discharge Vertically

upwards on same wall aspect

Fig 18.

13.0 room sealed flue installations (contd)

Page 19

STRATA1

38 & 38/46 COMBI

14.0 examples of calculating

flue pressure loss

example 1

A Strata 1-38/46 combination boiler is proposed to be installed with a room sealed concentric flue taking an all horizontal route to a wall terminal that has the flue gas duct extended to a more acceptable termination position to avoid a potential visual nuisance problem with flue gas pluming.

Flue system comprises: 3 x 90° concentric bends 8 metres concentric flue tube 3 x 80mm 90° flue gas elbows 3 metres 80mm flue gas tube Concentric wall terminal

Resistance = 1 x 80/125 concentric wall terminal @ 5.0 Pa = 5.0 3 x 80/125 90° concentric bends @ 4.0 Pa = 12.0 8 x 1m lengths 80/125 concentric tube @ 4.0 Pa = 32.0 3 x 90° DN80 bends @ 2.5 Pa = 7.5 3 x 1m lengths DN80 PPS tube @ 2.5 Pa = 7.5 1 x DN80 open termination with mesh @ 2.5 Pa = 2.5

Total Resistance = 66.5 Pa

conclusion: Total resistance is less than 100 Pa therefore there will be no effect on boiler output. System may be installed as proposed.

example 2

A Strata 1-38/46 combination boiler is proposed to be installed with a room sealed concentric flue taking a part horizontal (6m) and part vertical (10m) route to a vertical concentric roof terminal set. The flue system includes 3 Nr 90° concentric bends and is installed to run within the building.

Resistance = 3 x 80/125 90° concentric bends @ 4.0 Pa = 12.0 16 x 1m lengths 80/125 concentric tube @ 4.0 Pa = 64.0 1 x 80/125 concentric roof terminal with cap @ 7.5 Pa = 7.5

Total Resistance = 83.5 Pa

There is 10 m of vertical flue which will create an updraught of 33 Pa. Therefore final operating resistance = 83.5 - 33 = 50.5 Pa.

conclusion: Total resistance is less than 100 Pa therefore there will be no effect on boiler output. System may be installed as proposed.

50 100 200150 250 300 350 400 450 500

Strata 1 - 38. 38/46 Combi

effect of flue

system resistance

on boiler output

Boiler Output kW at: Flow 80°C Return 60°C

Flue System Resistance - Pa

0 2 6 10 14 18 22 26 30 34 38

110

130

100

120

140

48 1612 20 24 28 32 36 40

thermal updraught when

flue gas temp 80°C and

outside temp -5°C

Draught - Pa

Vertical Flue Lengths - metres

A = Insulated or within the building B = Uninsulated and exterior to the building

Page 20

STRATA1

38 & 38/46 COMBI

14.1 calculating

flue resistance

If a flue terminal is positioned within 2 m above ground level or any upper part of a building where

people have general access (e.g. balcony etc) then the terminal should be fitted with an appropriate guard.

The flue terminal of a Strata 1 boiler will plume heavily and care must be taken when selecting a

terminal position to ensure that a "nuisance situation" is not created.

15.0 flue

terminal positions

flue terminal positions

H,I

F D

B,C

7.5

11.25

5.5

2.75

5.0

2.5

7.0

2.0

1.0

4.0

2.0

3.5

4.0

2.0

Component.

80/125 Concentric Wall Terminal 80/125 Concentric Roof Terminal

Without Rain Cap 80/125 Concentric Roof Terminal

With Rain Cap 1m Length 80/125 Concentric Tube 93° 80/125 Concentric Bend 45° 80/125 Concentric Bend 1m Length DN 80 PPS Flue Tube (Fluegas) 93° DN 80 PPS Flue Bend (Fluegas) 45° DN 80 PPS Flue Bend (Fluegas) Room Sealed Chimney Cap 1m Length DN 100 PPS Flue Tube 93° DN 100 PPS Flue Bend (Fluegas) 45° DN 100 PPS Flue Bend (Fluegas) DN 80 Open Termination with Mesh DN 100 Open Termination with Mesh 80/125 Concentric to 2 x 80 Tubes Adaptor 1m length DN80 PPS Tube (Air) 93° DN 80 PPS Bend (Air) 45° DN 80 PPS Bend (Air)

The excess pressure available for overcoming the

frictional resistance of a flue system is 100 Pa.

The adjacent table of flue component resistances will assist the designer in calculating total flue system frictional loss.

If the total installed flue system resistance exceeds 100 Pa, then the result will be a reduction in boiler output. Reference to the “Effect of Flue System Resistance On Boiler Output”, graphs will assist. If the resistance of a proposed flue system has an unacceptable effect on boiler output, then a larger diameter flue tube should be selected.

Thermal up-draught is generated in a vertical flue system, reducing the resistance of the system. Reference to the “Thermal Updraught Graph” will provide a figure in Pa, which may be deducted from the total calculated flue system resistance.

NOTE: Does not apply to horizontal sections of a flue system.

Resistance Pa Strata 38 38/46

Fig 19.

Page 21

STRATA1

38 & 38/46 COMBI

minimum dimensions of flue terminal positions

See fig 19.

Dimension Terminal Balanced flue Non room

position room sealed sealed

A Directly below an opening, air 300mm 300mm

brick, windows etc. Not recommended.

B Below gutters, soil pipes or 75mm 75mm

drain pipes.

C Below eaves. 200mm 200mm

D Below balconies or car port 200mm 200mm

roof. Not recommended.

E From a vertical drain pipe or 150mm 150mm

soil pipe.

F From an internal or 300mm 200mm

external corner.

G Above ground, intersecting 300mm 300mm

roof or balcony level.

H From a surface facing 2000mm 2000mm

the terminal.

I From a terminal facing 2000mm 2000mm

the terminal.

J From an opening in the car port 1200mm 1200mm

(e.g. door, window) into dwelling.

K Vertically from a terminal on the 1500mm 1500mm

same wall.

L Horizontally from a terminal on 300mm 300mm

the same wall.

M From a vertical structure on 500mm N/A

the roof.

N Above intersection with roof. 500mm 150mm

P Directly above an opening, air brick, 300mm 300mm

window etc.

Q Horizontally to an opening, air brick, 500mm 500mm

window etc.

15.0 flue terminal positions (contd)

but installation not recommended.

Page 22

STRATA1

38 & 38/46 COMBI

16.0 ventilation requirements

single appliances

Table 1 Room installation - non room sealed flue.

Natural ventilation direct to outside air.

Ventilation openings free area cm

220

Table 2 Room Installation - Non Room Sealed Flue

Natural ventilation from adjacent room which is directly ventilated to outside air.

Ventilation openings free area cm

220

With adjacent room similarly ventilated direct to outside air

Table 3 Room Installation - Room Sealed Flue

There are no specific requirements for a room to be ventilated where the appliance is room sealed. However, consideration should be given to providing ventilation for general cooling,

Table 4 Compartment Installation - Non room sealed flue

Natural Ventilation Direct to outside air

Ventilation openings free area cm

High Level Low Level

230 460

Table 5 Compartment Installation - Non room sealed flue

Natural Ventilation from Adjacent room

Ventilation openings free area cm

High Level Low Level

460 920

With adjacent room having a ventilation opening of not less than 220cm

direct to outside air.

The room or space in which the Strata 1 boiler is installed may require to be ventilated in accordance with BS5440: Part 2: 2000, or BS6644:1991 as a appropriate.

The following tables must be read to ascertain the amount of ventilation required for the installation of a single appliance and has been calculated from BS 5440: Part 2: 2000.

Page 23

STRATA1

38 & 38/46 COMBI

16.0 ventilation requirements (contd)

Table 6 Compartment Installation - Room sealed flue

Natural Ventilation direct to outside air

Ventilation openings free area cm

High Level Low Level

230 230

Table 7 Compartment Installation - Room Sealed Flue

Natural Ventilation from Adjacent Room

Ventilation openings free area cm

High Level Low Level

460 460

Multiple Appliances Installed in the Same Room or Space

Where multiple Strata 1 boilers are installed in the same room or space then the aggregate of the appliance inputs must be taken to determine (from the following data) the amount of ventilation required.

Appliance Gross Heat Inputs Should be taken as:-

51.1kW

Table 8 Non Room Sealed Flue Installations

Natural Ventilation Direct to Outside Air.

Low Level (Inlet): 540cm2 plus 4.5cm

per kW in excess of 60kW total rated input.

High Level (Outlet): 270cm2 plus 2.25cm

per kW in excess of 60kW total rated input.

Table 9 Room Sealed Flue Installations

Natural Ventilation Direct to Outside Air (Ventilation recommended for cooling purposes)

Low Level (Inlet): 4.5cm

per kW of total rated input.

High Level (Outlet): 4.5cm

per kW of total rated input.

Page 24

STRATA1

38 & 38/46 COMBI

17.0 hydraulic system

design

● The Strata 1 boiler can be operated to serve a heating load in a number of ways:

1. Constant flow temperature, with the option to set either high temperature (85°C), medium temperature (70°C) or low temperature (55°C).

2. Direct-on-boiler weather compensated flow temperatures, with adjustable maximum flow temperature.

3. Underfloor heating coils via a VT mixing valve with a maximum flow temperature of 55°C plus a second circuit (eg. radiators) operating with direct-on-boiler weather compensated temperatures.

● Flow to return drop (∆t). The microprocessor controls monitor return temperature and the facility to operate at a set ∆t (by pump speed modulation) is a standard and most important feature and will, where possible, maintain the ∆t across the boiler at 20°C, as the lower the return temperature, the higher the operating efficiency. HT and MT systems should be designed for ∆t 20°C and LT (underfloor coils via a mixing valve) systems ∆t 10°C. Designing for a ∆t 20°C gives the added cost saving advantage of smaller pipe sizes and pumps.

● The Strata 1 includes an ‘in built’ primary pump with a residual head pressure as listed below.

● Appliances may be installed as single units or in multiples.

● Single units may or may not require additional system pumps which will be dictated by the system

configuration and by the index resistance.

● Multiple units (and single units which require additional pumps), must always be installed with a low loss mixing header or similar arrangement. - see table below.

● The Strata 1/38 boiler has in built domestic hot water (remote stored) temperature control ability, and if required, the in built pumps may be used to provide the primary flow to a nearby indirect cylinder or calorifier with the boiler controlling a diverter valve in the main flow or return pipework.

● Provision within the system design must allow for: Low water pressure cut off device and water pressure gauge.

Boiler Power kW

Up to 38

76 114 152

Design ∆t 20°C

40mm 50mm 65mm 65mm

low velocity

mixing header

diameter sizing guide

Tube diameters refer to steel pipe and calculated using data from

CIBSE Guide C4

The following system schematics show a number of typical installation types to which the Strata 1 boiler

may be connected.

The Strata 1 is not limited to just the systems shown, and may be used in conjunction with many

commercially available control items.

For further advice or guidance on schematic designs or control options contact MHS Boilers Ltd.

Boiler Model

Strata 1/38

Strata 1/38-46 Combi

Pressure Metres wc

3.3

2.4

Boiler Model

Strata 1/38

Strata 1/38-46 Combi

Pressure Metres wc

1.0

in-built boiler pumps

approx residual head

pressure at max speed

in-built boiler pumps

approx residual head

pressure at min speed

Page 25

STRATA1

38 & 38/46 COMBI

OS = Outside air temperature sensor,

used where direct-on-boiler weather compensated flow temperatures are required.

C = Room Controls, either RE2132

modulating room unit from MHS Boilers or a room thermostat.

PS = Low water pressure cut off switch.

system type 1

Typical single Strata 1 boiler installation serving heating only where the boiler's own inbuilt circulating pump is used to circulate the water around the system (used only where system index resistance < pump residual head - see page 24). Flow temperature may be fixed/constant or weather variable.

17.0 hydraulic system design (contd)

Waste

Condense

DOC

Expansion

Vessel

CWM

Strata 1- 38 Boiler

Strata 1- 38/46 Combi

LSV

Strainer

Heating Load

Filling Point

DOC

Page 26

STRATA1

38 & 38/46 COMBI

OS = Outside air temperature sensor,

used where direct-on-boiler weather compensated flow temperatures are required.

C = Room controls, either RE2132

modulating room unit from MHS Boilers or a room thermostat.

S/T = Hot water temperature controls,

either:- “S”, an HWS temperature sensor from MHS Boilers or “T”, a cylinder thermostat.

PS = Low water pressure cut off switch.

Divertor valve must be so installed to spring return to heating.

Divertor valve will require SPDT relay if not spring return.

system type 2

Typical single Strata 1 boiler installation serving domestic hot water (not Combi) and heating where hot water has priority via a divertor valve. The in-built circulating pump within the boiler is used to circulate the system (used only where system index resistance < pump residual head - see page 24). Flow temperature to hot water is constant and flow temperature to heating may be constant or weather variable.

17.0 hydraulic system design (contd)

Waste

Condense

Calorifier/Indirect

Hot Water Cylinder

Strata 1- 38 Boiler

DOC

Expansion

Vessel

DOC

Strainer

Heating Load

LSV

DOC

Divertor

Valve

Filling

Point

DOC

CWM

Page 27

STRATA1

38 & 38/46 COMBI

OS = Outside air temperature sensor.

Used where direct-on-boiler weather compensated flow temperatures are required.

C = Room controls, either RE2132

modulating room unit from MHS Boilers or a room thermostat.

PS = Low water pressure cut off switch.

System pump to be no greater than 2 amps

system type 3

Typical Single Strata 1 boiler installation serving heating only and using a low velocity mixing header where system index resistance exceeds in-built boiler pump residual head see page 24. Flow temperature may be fixed/constant or weather variable.

17.0 hydraulic system design (contd)

Waste

Condense

Expansion

Vessel

DOC

Point

Filling

CWM

Strata 1- 38 Boiler

Strata 1- 38/46 Combi

LSV

Strainer

AAV

DOC

Vertical

Low Velocity

2A Max.

Heating Pump

Mixing Header

Max Velocity 0.5m/s

DOC

Strainer

Heating Load

DOC

Page 28

STRATA1

38 & 38/46 COMBI

OS = Outside air temperature sensor. Used where

direct-on-boiler weather compensated flow temperatures are required.

C = Room controls, either RE2132 modulating room

unit from MHS Boilers or a room thermostat.

S/T = Hot water temperature controls, either: “S”, an

HWS temperature sensor from MHS Boilers or “T”, a cylinder thermostat.

PS = Low water pressure cut off switch.

Divertor valve must be so installed to spring return to heating.

Divertor valve will require SPDT relay if not spring return.

System pump to be no greater than 2 amps.

system type 4

Typical Single Strata 1 boiler installation serving heating & domestic hot water (not Combi). Hot water is priority and is served via a divertor valve and the boiler's in built circulating pump where index loss through HWS primaries is less than boiler pump residual head*. Heating circuit index loss exceeds boiler pump residual head* and is served via a low velocity mixing header and a separate pump. Heating flow temperature may be fixed/constant or weather variable.

* See page 24

17.0 hydraulic system design (contd)

Waste

Condense

Calorifier/Indirect

Hot Water Cylinder

Strata 1- 38 Boiler

Strainer

Heating Load

Divertor

AAV

Valve

Expansion

Vessel

DOC

LSV

DOC

Vertical

Low Velocity

2A Max.

Heating Pump

IVIV

Mixing Header

Strainer

Max Velocity 0.5m/s

DOC

CWM

Filling

Point

Page 29

STRATA1

38 & 38/46 COMBI

OS = Outside air temperature sensor.

Used where direct-on-boiler weather compensated flow temperatures are required.

C = Room controls, either RE2132

modulating room unit from MHS Boilers or a room thermostat.

S/T = Hot water temperature controls,

either “S”, an HWS sensor from MHS Boilers or “T”, a cylinder thermostat.

PS = Low water pressure cut off switch.

System pumps to be no greater than 2 amps

system type 5

Typical Single Strata 1 boiler installation serving heating & domestic hot water (not Combi) with hot water priority. Hot water & heating circuits both have index resistance exceeding boiler pump residual head* & are served by independent pumps from a low velocity mixing header. Heating flow temperature may be fixed/constant or weather variable.

* See page 24

17.0 hydraulic system design (contd)

Expansion

DOC

Condense Waste

Vessel

Filling Point

Strata 1-38Boiler

Strainer

2 A Max.

LSV

NRV

DOC

Vertical Low Velocity

Mixing Header

Max Velocity

0.5 m/s

NRV

HWS Primary

Pump 2 A Max.

DOC

Strainer

DOC

AAV

Heating Pump

Heating Load

Calorifier/Indirect

Hotwater Cylinder

DOC CWM

Page 30

STRATA1

38 & 38/46 COMBI

system type 6

Typical Single Strata 1 boiler installation serving domestic hotwater (not Combi) and radiator heating zone and an underfloor coil zone all via a low velocity mixing header. The HWS will always have priority. The 2Nr heating zones may operate independently via 2 Nr separate room units. The 2 Nr heating zones will always be weather compensated but may have differing compensation slopes.

17.0 hydraulic system design (contd)

OS = Outside air temperature sensor. Provides outside air temperature reference for both heating zones.

MRO3 =Pumps and mixer regulation control box from MHS Boilers provides pump control for both heating zones i.e.

auto operation, frost protection and summer stand still protection running. Provides drive for underfloor coil zone VT mixing valve with max flow temperature limitation set at 55ºC. Includes controls for compensation of under floor coils. Max pump motor loads 2A.

RC1 = RE2132 modulating room unit from MHS Boilers provides Time & Temperature control for radiator heating zone.

RC2 = As RC1 but for underfloor coil zone. Only to be used when RCI is used.

VS = Underfloor zone VT flow sensor (supplied with MR03).

S/T = Hot water temperature controls, either “S”, an HWS temperature sensor from MHS Boilers or “T”,

a cylinder thermostat.

PS = Low water pressure cut off switch.

* Not applicable to Strata 1 - 38/46 Combi

S/T

Calorifier or

Radiator Zone

Indirect Cylinder*

DOC

A Max.

Radiator

Zone Pump 1

AAV

Combi

Boiler or

Strata 1-38

Strata 1-38/46

HWS Primary

Pump* 2 A Max.

NRV

Under Floor Zone

VT Pump

U/Floor VT 1 A Max.

Vertical

NRV

MRO3

Waste

Condense

Mixing Valve

Low Velocity

Mixing Header

V Max 0.5m/s

Strainer

DOC

LSV

Under Floor

Coils Zone ∆t 10ºc

DOC

Vessel

Expansion

Strainer

DOC

Point

Filling

CWM

Page 31

STRATA1

38 & 38/46 COMBI

OS = Outside air temperature sensor,

used where direct-on-boiler weather compensated flow temperatures are required.

C = Room temperature controls e.g.

RE2132 modulating room unit from MHS Boilers, or, separate time clock & room thermostat.

FS = Flow temperature sensor

RS = Return temperature sensor

S = Hot water temperature sensor or

thermostat

KKM2 = Modulating Kaskade Manager. Up

to 9Nr boilers may be controlled using 2Nr linked KKm2's.

PS = Low water pressure cut off switch.

* Not applicable to Strata 1 - 38/46 Combi

1* = Filling point. In accordance with BS

6644, automatic pressurisation unit must be installed when the boilers input is greater than 60kW.

system type 7

Typical Multiple Strata 1 installation. Boilers controlled by modulating Kaskade manager which also has the facility to control heating & domestic hot water production. Heating flow temperature may be fixed/constant or weather variable. Hot water has priority.

17.0 hydraulic system design (contd)

DOC

KKM 2

Heating Load

NRV

AAV

Heating Pump

2A. Max

NRV

Strata 1

HWS Primary

Pump

Boiler

2A. Max

DOC

Hot Water

Calorifier or

Indirect Cylinder

Low Velocity

Mixing Header

Max Velocity 0.5m/s

NRV

DOC

Expansion

LSV

DOC

Filling

Vessel

Point

CWM

Strainer

IV IV

Strainer

IVIV

Boiler

Strata 1

Waste

Condense

Page 32

STRATA1

38 & 38/46 COMBI

typical schematic arrangement where

system has multiple pumps that will

operate at the same time

WC = Wiring Centre/Junction Box

RS = Room Thermostat

CS = Cylinder Thermostat

PS = Low water pressure cut off switch.

OS = Outside Air Sensor, install when

weather compensated heating flow temperatures are required

system type 8

Typical Single Strata 1 boiler installation serving heating and domestic hotwater via a system pump and 2Nr 2Port motorised valves with conventional controls i.e. programmer, room stat & cylinder stat.

17.0 hydraulic system design (contd)

Heating Load

M/Valve

System Pump

Reg Valve

Indirect Cylinder/Calorifier

IVIV

Strainer

AAV

Condense

Waste

Flow Header

AAV

LSV

DOC

Vertical Low Velocity

Strainer

Expansion

Vessel

Mixing Header

Max Velocity

0.5 m/s

DOC

Filling Point

CWM

Boiler/s

Circuit Pumps That Can/Will Run At The Same Time

Low Velocity Mixing Header

Max Velocity 0.5m/s

Page 33

STRATA1

38 & 38/46 COMBI

17.2 water treatment

system cleaning

The entire primary system must be thoroughly cleansed and flushed to remove debris, flux residues etc before opening the boiler isolation valves & flooding the boiler. Particular care must be taken where the Strata boiler is being retro-fitted into an old/existing system, as system silt or magenite can be very damaging to the new boiler.

Following cleansing and flushing the system must be dosed with a good quality water treatment to prevent corrosion and the formation of scale. Failure to observe these requirements will render the guarantee on the product void. Cleansing, flushing and water treatment must be carried out in accordance with the requirements of BS 7593:1992 prior to commissioning the unit.

Repeated draining and refilling of the system must be avoided as this is very damaging to the boiler. The boiler must not be operated without the system water being correctly and adequately dosed with an appropriate corrosion inhibitor.

For specific guidance on water treatment, direct contact is advisable with:-

Betz Dearborn Limited Fernox Widnes Tandem House Cheshire Marlowe Way, Croydon WA8 8UD Surrey CR0 4XS Telephone: 0151 495 1861 Telephone: 0208 665 6666

For Category 4 systems, the approved method of filling must comprise of the following components in the arrangement shown;

● Control Valve

● Strainer

● Verifiable Backflow Device with

Reduced Pressure Zone (RPZ Valve).

Incorporating a 'Type BA' air gap.

● Tundish

● Control Valve

Further more, in accordance with BS6644, for boiler/s with an input greater than 60kW, an automatic pressurisation unit must be installed to automatically replenish any lost or evpourated water.

The pressurisation unit must comprise of the following components;

● A Cistern fitted with a Float Operated Valve incorporating either a 'Type AG' (C-3), or 'Type AF' (C-4)

air gap.

● A Presssure Booster Pump fitted with a Single Check Valve

● A Pressure Reducing Valve

● A Pressure Switch

For information on a comprehensive range of pressurisation units please contact MHS Sales.

17.1 filling the system

The initial filling of a sealed heating system, and subsequent refilling, must be by a method that has been approved by the Water Regulation Advisory Scheme (WRAS) for that type of heating system. ie. Domestic (In-house) Fluid Category 3 (C-3). Non Domestic (Other than In-House) Fluid Category 4 (C-4).

For Category 3 systems, the approved method of filling must comprise of the following components in the arrangement shown;

● Control Valve incorporating a Double Check

Valve on the mains cold water pipework.

● Temporary Connecting hose, which must

be disconnected after use.

● Control Valve, on the heating system.

MCWS

DCV HOSE

Heating System

MCWS

CV CV

Strainer

Heating System

Tundish

RPZ

Page 34

STRATA1

38 & 38/46 COMBI

17.4 hydraulic system design

domestic hot water - Combi

typical hot/cold water installation using Strata 1-38/46 combination boiler

typical multiple Strata 1-38/46 combination boiler

domestic hot water installation

DOC

To Hot Water

Draw Off Points

To Cold Water

Draw Off Points

To Hot Water

Draw Off Points

To Cold Water

Draw Off Points

Stop

Valve

To Heating System

Fill Point

BS1010

Stop Valve

BS1010

Stop Valve

Incoming Cold Water Main

Important Note:

1. From the incoming cold water main to the cold inlet connection on the boiler there must be no non return valves or loose jumper type valves.

2. Under no circumstances must there be installed a secondary return circulation arrangement.

Important Note:

Cold water feed and hot water flow out connections must be reverse return as shown. See also notes 1 and 2 above.

DOC

Stop Valve

DOC

CWM

Strata 38/46

Strata 38/46Strata 38/46

17.5 Combi boiler - prevention of scale

in water to water heat exchanger

In hard water supply areas, it is highly recommended to install a suitable proprietary in-line scale reducing device into the cold supply pipe serving the Strata 1/38-46 combi boiler. The scale reducing device should be installed in accordance with the instructions supplied with the device.

17.3 care with the use of

soldering flux

The Strata 1 boiler has a primary heat exchanger fabricated from 316L stainless steel. It is most important that the compatibility of any flux is checked with the flux supplier before use, and that any flux manufacturers recommendations are strictly followed with regards to use in conjunction with stainless steel.

IV IV

Page 35

STRATA1

38 & 38/46 COMBI

17.6 Combi boiler hot water

system pipework pressure drop

guidance on hot water pipework pressure drop

25m 20m

15m 10m

Domestic Hot Water Flow Rate Litres/minute

Flow Rate - Pressure Drop - Distance Chart For Installation Utilising all 15mm Copper Tube

Approximate Pressure Drop - bar

For every 90° change in direction allow 1m

Total length of pipe, from incoming cold water main to appliance and from appliance to hot water draw off point

}

Domestic hot water temperature rise 50°C

Domestic hot water temperature rise 35°C

25m 20m 15m 10m 5m

Domestic Hot Water Flow Rate Litres/minute

Flow Rate - Pressure Drop - Distance Chart For Installation Utilising all 22mm Copper Tube

Approximate Pressure Drop - bar

For every 90° change in direction allow 1m

Total length of pipe, from incoming cold water main to appliance and from appliance to hot water draw off point

}

Domestic hot water temperature rise 50°C

Domestic hot water temperature rise 35°C

Example:

A wash hand basin is to be served and the length of pipe involved is 20m. The entire installation is in 15mm copper tube and reference to the graph right shows that the pressure drop when delivering water at a temperature rise of 35°C (hand hot) will be 1.5 bar.

● Ensure adequate working water pressure and flow rate availability.

● Consider that not only is water volume required for instantaneous production of hot water, but cold

water most likely will be required simultaneously ie: shower blending, hot and cold taps running together, toilet flushing etc.

● Consider that as an absolute minimum the cold water main must be capable of supplying 18

litres/minute into the property. The required working water pressure will be dependent on the length of run to the draw off, the pipe size and any resistance at the drawoff (resistance of mixer taps, blenders etc). Reference to the flow rate/pressure drop charts will give guidance with regards to the hot water installation pipework (the resistance of the boiler’s water to water heat exchanger is included in the pressure drops indicated). The additional working water pressure required for simultaneous cold water flow can be calculated by reference to CIBSE Guide C4.

17.7 Combi boiler - domestic hot water

system design considerations

3.0

2.5

2.0

1.5

1.0

0.5

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

12 14 16 18 20

Page 36

STRATA1

38 & 38/46 COMBI

18.0 electrical

connections

The electrical connections to the Strata 1 boiler are made via a plug/socket arrangement (mains) and labelled terminal rails which are located within the boiler case and to the left of the gas valve assembly. Connections must only be made using appropriate diameter multi strand flex cables and cable entry must only be via the rubber glanded cable entry points located at the bottom rear l/h side of the appliance. If the boiler is to be room sealed flued then care must be taken to ensure the cable entries are reasonably air tight. For electrical connection rail detail see fig 20.

The low voltage rail is mounted in front of the mains voltage rail. To access the mains voltage rail, pull the quick release pins located diagonally either side of the low voltage rail.

RE2132

X 42

= Cylinder Thermostat or HWS Temperature Sensor (Not Combi)

Low Voltage Connection Rail

= Outside Air Temperature

= RE 2132 Modulating Room Unit

= Has No Function

= Earth Connection Rail

= External Gas Safety Shut Off Valve - LPG Only. Or External Central Heating Pump - Install LINK As Shown.

= Room Thermostat / MRO3 Mixer Control

= HWS Primary Pump or Divertor Valve

RE2132

24V dc

12 3 4R1R2R3 5 6

X 42

Mains Voltage Connection Rail

230 VAc - 50 Hz

-230V

LINK

Plug/Socket Supply 230V

L1 PE N

L1 N L1

L2 L1 N

Fig 20.

17.7 system design considerations (contd)

● Be generous with pipe sizing to keep pressure loss to a minimum.

● Consider that water will always take the least line of resistance and will take preference to an opened

drawoff closest to the boiler whilst perhaps ignoring/starving a simultaneous draw off further away

from the appliance.

● Consider installing flow restrictors into both hot and cold water draw off points to ensure reasonable

distribution of water around the building at times of multipoint draw off.

Cable Entry Glands

Page 37

STRATA1

38 & 38/46 COMBI

18.0 electrical connections (contd)

plan of internal electrical connections

230 VAC

FUSE 24V

FURIMAT 762

456

123

X4 X5

HSP TOP

253

ALARM CONTACT

K13

K20 K20

K17 K19

K12 K18

K14

X51

X47

X19

X18

X17

2 (X)

FUSE

X30 X31 X31

+SO PW-

Fan

STBA

STBW

X29

X28

X27

X26

Fan 24 VDC

Limit Thermostat

Fluegas

Limit Thermostat 1

M-T M-T

Water

Pump

Transformer

Ignition/

Ionisation

Boiler

Three way Valve

(Combi Only)

Gas Valve

X22

X41

Supply

X25

X23

230V AC

Mains Voltage Rail

HWS Primary Pump/Divertor Valve (L1+L2)+PE

L1 L2

Room Thermostat (L1+L2)+PE

MRO3 (L1+N)+PE

+++

KO = White K2 = Brown K3 = Green K4 = Gray K5 = Orange K6 = Blue K7 = Red K8 = Black K9 = Violet K12 = Yellow/White K13 = Braun/White K14 = Green/White K17 = Blue/White K18 = Red/White K19 = Black/White K20 = Violet/White

External LPG Solenoid Valve (L1+N) + PE

or Heating Pump

X16

Low Voltage Rail

MRO3

MIXER

X2 X3

RS232

K0 K6

K0 1

K7 K7

K6 K6

SSS

X13

STE

212 12 12 12 12

BTE

RTE

VTE

X14

X12

X10

Cold Water Inlet Temperature

Sensor (Combi only)

Instantaneous H.W. Flow

Temperature Sensor (Combi only)

Return Temperature Sensor

Flow Temperature Sensor

No Function

RE2132

Room Unit (R1+R2+R3)

Outside Air Temperature Sensor (3+4)

Cylinder Thermostat or

Hot Water Temperature Sensor (1+2)

Page 38

STRATA1

38 & 38/46 COMBI

18.0 electrical connections (contd)

typical electrical connection schematic

to suit system type 1

Once all controls are installed please refer to page 57/58 to ensure the correct function number is programed into the control panel.

Weiland

Plug/Socket

Earth Rail

Low Pressure Switch

break on Pressure Fall

Supply 230V 3A

230V ac - 50 Hz

RE2132

24V dc

Room Thermostat volt free enable

L1 N L1 N L2 L1 N

QAW 44 Optional Remote Sensor

Has No Function

+24V

PWM

GND

51 34

RE2132 Modulating Room Unit

Install only if direct-on-boiler weather compensated

flow temperature is required.

Install only one method of room temperature control.

If a modulating room unit is required, then do not

install also a room thermostat and vice versa.

234R1R2R356

Outside Air Sensor

Page 39

STRATA1

38 & 38/46 COMBI

18.0 electrical connections (contd)

typical electrical connection schematic

to suit system type 2 (not Combi)

Once all controls are installed please refer to page 57/58 to ensure the correct function number is programed into the control panel.

Supply 230V 3A

Weiland

Plug/Socket

Earth Rail

Divertor Valve

Motor Open/ Motor Shut Type

Earth Rail

230V ac - 50 Hz

Low Pressure Switch

break on Pressure Fall

Divertor Valve

Spring Return

Type

Room

Thermostat

L1 N L1 N L2 L1 N

Has No

Function

230V ac - 50 Hz

L1 N L1 N L2 L1 N

QAW 44 Optional Remote Sensor

SPDT Relay

Alternative arrangement

to Spring Return HWS

primary Divertor Valve

using motor open, motor

shut type valve.

24V dc

RE2132

234R1R2R356

+24V

PWM

GND

HWS Sensor

51 34

RE2132 Modulating Room Unit

Cylinder Stat

Install only if direct-on-boiler weather compensated

flow temperature is required.

Install only one method of room temperature control.

If a modulating room unit is required, then do not

install also a room thermostat and vice versa.

Install only one method of HWS temperature control.

(not Combi)

Outside Air Sensor

Page 40

STRATA1

38 & 38/46 COMBI

18.0 electrical connections (contd)

typical electrical connection schematic

to suit system type 3

Once all controls are installed please refer to page 57/58 to ensure the correct function number is programed into the control panel.

Supply 230V 3A

break on Pressure Fall

Weiland

Earth Rail

Plug/Socket

Low Pressure Switch

230V ac - 50 Hz

RE2132

24V dc

Room Thermostat

Link

Heating

+24V

GND

Pump 2A Max

51 34

L1 N L1 N L2 L1 N

Has No Function

PWM

volt free enable

QAW 44 Optional Remote Sensor

RE2132 Modulating Room Unit

Install only if direct-on-boiler weather compensated

flow temperature is required.

Install only one method of room temperature control.

If a modulating room unit is required, then do not

install also a room thermostat and vice versa.

234R1R2R356

Outside Air Sensor

Page 41

STRATA1

38 & 38/46 COMBI

18.0 electrical connections (contd)

typical electrical connection schematic

to suit system type 4 (not Combi)

Once all controls are installed please refer to page 57/58 to ensure the correct function number is programed into the control panel.

Supply 230V 3A

Earth Rail

Weiland

Plug/Socket

Divertor Valve

Motor Open/ Motor Shut Type

Earth Rail

230V ac - 50 Hz

Low Pressure Switch

break on Pressure Fall

Divertor Valve

Spring Return

Type

Room

Thermostat

L1 N L1 N L2 L1 N

Has No Function

230V ac - 50 Hz

L1 N L1 N L2 L1 N

QAW 44 Optional Remote Sensor

Open

SPDT Relay

Alternative arrangement

to Spring Return HWS

primary Divertor Valve

using motor open, motor

shut type valve.

Install only if direct-on-boiler weather compensated

flow temperature is required.

Install only one method of room temperature control.

If a modulating room unit is required, then do not

install also a room thermostat and vice versa.

Install only one method of HWS temperature control.

(not Combi)

The 3 way valve must be installed to spring return to

open the heating circuit.

24V dc

RE2132

234R1R2R356

+24V

PWM

GND

HWS Sensor

51 34

RE2132 Modulating Room Unit

Cylinder Stat

Outside Air Sensor

Page 42

STRATA1

38 & 38/46 COMBI

18.0 electrical connections (contd)

typical electrical connection schematic

to suit system type 5 (not Combi)

Once all controls are installed please refer to page 57/58 to ensure the correct function number is programed into the control panel.

Weiland

Plug/Socket

Earth Rail

Low Pressure Switch

break on Pressure Fall

Supply 230V 3A

230V ac - 50 Hz

RE2132

24V dc

HWS Primary Pump 2A Max

Room Thermostat

Link

Heating

L1 N L1 N L2 L1 N

Has No Function

+24V

PWM

GND

Pump 2A Max

QAW 44 Optional Remote Sensor

51 34

RE2132 Modulating Room Unit

volt free enable

Install only if direct-on-boiler weather compensated

flow temperature is required.

Install only one method of room temperature control.

If a modulating room unit is required, then do not

install also a room thermostat and vice versa.

Install only one method of HWS temperature control.

234R1R2R356

HWS Sensor

Cylinder Stat

Outside Air Sensor

Page 43

STRATA1

38 & 38/46 COMBI

18.0 electrical connections (contd)

typical electrical connection schematic

to suit system type 6

Once all controls are installed please refer to page 57/58 to ensure the correct function number is programed into the control panel.

Supply 230V 3A

Rad Zone

Pump 1A max

Weiland

Earth Rail

Plug/Socket

Low Pressure Switch

break on Pressure Fall

Pump #2

Underfloor Zone

VT Pump

1A Max. Pump #3

PE L

Underfloor Zone

VT Mixing Valve

NPEL2

230V ac - 50 Hz

RE2132

24V dc

L1 N L1 N L2 L1 N

234R1R2R356

2A Max

Has No Function

HWS Sensor (not Combi)

HWS Primary Pump (not Combi)

+24V

PWM

GND

621

Moulded Plugs

QAW 44 Optional Remote Sensor

RE2132 Modulating

51 34

Room Unit (Rad Zone)

MRO3

X3X16

R6 R5 R4

Cylinder Stat (not Combi)

Underfloor Zone VT Flow Sensor

+24V

PWM

Outside Air Sensor

NOTE: All connections into MR03 are made

Via labelled factory fitted cables with the

exception of the underfloor Zone RE2132

which is cabled by the installer.

RE2132 Modulating Room Unit (U/floor circuit)

43251

QAW 44 Optional Remote Sensor

Install only one method of HWS temperature control.

X3,X16 = Controls Sockets on Control panel.

MR03 has factory made on plugs and leads

for these connections.

If system only has 1Nr RE2132 unit installed, then this

must be connected to the boiler 24V dc rail.

Page 44

STRATA1

38 & 38/46 COMBI

18.0 electrical connections (contd)

typical electrical connection schematic

to suit system type 7

Once all controls are installed please refer to page 57/58 to ensure the correct function number is programed into the control panel.

NOTE:

No connections,

other than those

shown are to be

26 28 30 32 34

23 25 27 29 31 33

X2 X4

14 16 18 20 22 24

11 13 15 17 19 21

made to the boilers.

Boilers

Not Used Additional

+24V

GND

PMW

* Outside Air Sensor

* HWS Sensor

Return sensor

Flow Sensor

No3

No2

No1

1 1 1

N PE L1

QAW44 Optional

Remote Sensor

Supply 230V

R1/1 R1/2 R1/3

* External Controls For Heating Circuit

Relay R1

Low Pressure Switch

break on Pressure Fall

Boiler

LVTR LVTR LVTR

RE2132 Modulating

Room Unit

43521

16 18 20 22

13 15 17 19 21

* Cylinder Stat/HWS Time Switch

Control Options

Alternative External

4 6 10 12

= Low Voltage Terminal Rail on Boilers

= Weiland Plugs/Sockets on Boilers

LVTR

13579

= Terminal Rails on KKM2 Kaskade Manager

X1, X2, X4

N L

Supply 230V

Heating Circuit Pump 230V 2A Max

HWS Primary

Pump 230V 2A max

- If Required

Page 45

STRATA1

38 & 38/46 COMBI

18.0 electrical connections (contd)

typical electrical connection schematic

to suit system type 8

Once all controls are installed please refer to page 57/58 to ensure the correct function number is programed into the control panel.

Weiland

Plug/Socket

Low Pressure Switch

Earth Rail

break on Pressure Fall

Supply 230V 3A

230V ac - 50 Hz

RE2132

24V dc

L1 N L1 N L2 L1 N

Has No Function

Outside Air Sensor

Junction

Box

L567L910LLNNEE

123

Room Stat

Cylinder Stat

(not Combi)

HW-MV & CH-MV

= Typical spring return type motorised valves

with end switches

Install only if direct-on-boiler weather compensated

flow temperature to heating circuit is required (recommended).

HW-MV CH-MV

System

Pump Max 2A

2 3 4 R1 R2 R3 5 6

Page 46

STRATA1

38 & 38/46 COMBI

18.0 electrical connections (contd)

domestic hot water temperature sensor

If a hot water temperature sensor (from MHS Boilers) is used to sense the temperature of stored hot water, then this should be inserted into a pocket or surface mounted to measure the water temperature at approximately 1/3 of the height of the hot water vessel up from the base of the vessel.

remote fault indication

The Strata 1 boiler includes a built in fault alarm relay with volt free contacts for interface with, if required a remote alarm indicator. The volt free contacts within the boiler control panel will close in the event that the boiler goes to a fault resulting in boiler lockout. The volt free contacts indicate “common alarm” upon closing. The actual fault description will be displayed upon the LCD screen of the boiler. Connection to the volt free contacts is made via an alarm plug and lead assembly available from MHS Boilers Ltd. The alarm plug and lead connects to socket x9 located behind the cover plate on the top front of the control panel. To release cover plate, pull quick release pins located at either side.

outside air temperature sensor

If weather compensated flow temperature (recommended for best seasonal efficiency and comfort) is required, then the supplied air sensor must be installed and electrically connected to the boiler. The outside air sensor should be installed on the exterior face of a north facing wall, away from any artificial influences such as ventilation discharge grilles or in direct sunlight. Ø 5mm wall fixings and screws are provided.

Length m

Up to 35 35 to 70

70 to 140

Cable Diameter mm

0.25

0.5

1.0

X9 Socket (on control panel)

X9 Alarm Plug & Lead Assembly

Remote Aarm Circuit

Cable Detail

Length m

Up to 35

35 to 70

70 to 140

Cable Diameter mm

0.25

0.5

1.0

Cable Detail

TOP

Outside Air Temperature Sensor

Page 47

STRATA1

38 & 38/46 COMBI

In addition to the ability of the boiler to be connected to traditional industry standard control systems, MHS Boilers can supply a range of dedicated matched controls which not only simplify the selection of controls but in addition enhance the efficiency of the boiler and comfort conditions within the building.

combination pump and underfloor system mixing valve control

MRO3 module: For single boiler applications. A small and neat wall mounted control box which allows the boiler to control two different heating circuits.

Circuit 1 - A variable temperature circuit with pump and mixing valve (240v) for use with underfloor

coils where the maximum flow temperature = 55°C.

Circuit 2 - A pumped heating circuit (eg radiators) where the flow temperature is direct-on-boiler

weather compensated variable. The MRO3 has the facility to connect an RE2132 modulating room unit to provide modulating room temperature and time control over the underfloor circuit. A second RE2132 unit may be connected directly to the boiler to control Circuit No.2.

modulating room temperature control

RE2132 room unit: A compact digital room temperature control that will modulate boiler power according to room temperature requirements.

key features

● In-built optimising time control and temperature sensor.

● Three temperature levels including frost protection.

● Holiday programmable.

● Can be used as a remote control for parallel shift of compensation slope.

● Self learning.

● Can be connected to an individual boiler, on MR03 (underfloor) control or a KKM2

sequence controller.

● QAW44 an additional tamper proof sensor can be wired to the RE2132 to allow sensing of remote

areas away from RE2132.

optional matched controlsoptional matched controls

Page 48

STRATA1

38 & 38/46 COMBI

optional matched controls (contd)

multiple boiler Kaskade manager

KKM2 modulating sequence controller:

A comprehensive compact wall mounted microprocessor control panel which allows the control of up to five Strata 1 boilers. The KKM2 provides fully modulating control over the connected boilers ensuring precise output control and maximum efficiency.

In addition to boiler control, the KKM2 can provide the drive signal for a heating circuit pump and can provide control for stored domestic hot water (with priority over heating). Domestic hot water may be charged using either a diverter valve or primary pump, either of which are driven from the sequencer.

External control input is via either a volt free contact (eg time switch), 0-3v or 10v input, or an RE2132 modulating room unit plus necessary temperature sensors. Heating flow temperatures may be either constant temperature or direct-on-boiler weather compensated variable (by means of the in-built compensator). If more than five boilers are required to be controlled, then additional KKM2’s may be slaved to the first control with slave capacity of four boilers per each additional sequencer. Standard features include pump overrun, boiler load rotation, frost protection and pump exercise program.

0-3/0-10 volt control

The Strata 1 can be operated via 0-3 volt or 0-10 volt control. The connection details are shown in fig 22. For further details on 0-3 or 0-10 volt control please contact the Technical Department.

0-10 Volt Control 0-3 Volt Control

24V dc

RE2132

2 3 4 R1 R2 R3 5 6

Has No

Function

234R1R2R356

24V dc

RE2132

0 - 3 Volt

0 - 10 Volt

Control

Adaptor

0 - 10 Volt

Control

Has No

Function

Page 49

STRATA1

38 & 38/46 COMBI

a) Ensure system has been thoroughly cleansed and flushed, any strainers have been cleaned and that the

appropriate water treatment has been added to the system to prevent corrosion, scale formation etc. Failure to comply with this will void all warrantee applied to the boiler.

b) Ensure the system and boiler has been properly fully flooded and vented of air and the cold fill pressure at

the boiler is at a minimum 0.5 bar. Air vent for primary heat exchanger is located to the right hand side of the top of the boiler chassis.

c) Check that the pump within the boiler is free to rotate by removing the vent screw in the end of pump

motor and checking that the impeller shaft rotates freely when turned with an appropriate sized

screwdriver. Replace vent screw. d) Ensure the appliance has been converted to burn the type of gas available on site. e) Ensure Gas supply has been purged and there is the availability of working inlet pressure of nominal 20mbar

(Nat gas) or 37 mbar (LPG), and that the appliance supplied is suitable for the gas type

being used. If the boiler is required to be converted to an alternative you must contact MHS Boilers for

assistance. f) Check that the flue installation has been properly made. g) Check that a condense waste pipe (in plastic - copper tube is not acceptable) has been connected to the

boiler and that the syphon cleaning point cap is in place. h) Where the appliance is taking air for combustion from the room in which it is installed - ensure an adequate

provision for ventilation has been made. i) Ensure that there is an adequate heat load available. j) Ensure that the electrical connections have been made correctly. k) Combi boiler – ensure domestic hot water pipework is flushed and fully flooded. l) Combi boiler – ensure primary side of water to water heat exchanger is fully vented by releasing air from

vent located on the top right hand side of the insulated heat exchanger. It is recommended to vent heat

exchanger several times during initial commissioning. m) Set the low pressure switch to operate at 0.5 bar.

19.0 commissioning

the Strata 1 boiler

The Strata 1 boiler should be expertly commissioned by a competent engineer who will need, in addition to standard hand tools, a U tube manometer and a combustion analyser.

Before attempting to set the Strata 1 38 or 38/46 combi boiler to work, the following check list must be worked through. See 19.1.

The data badge of the appliance must be marked to indicate the conversion has been undertaken. Refer to the commissioning section for guidance on Combustion Adjustment.

Boiler Type White Premix Air Box Hole White Premix Air Box Hole Strata 1 38 Boiler Plug with 15mm Plugs Leave Open Strata 1 38/46 Combination Boiler Plug with 15mm Plugs Plug with 13mm Plug

19.1 Pre-commissioning

checks

19.2 LPG Conversion

Procedure

The Strata 1 38 and 38/46 combination boilers can be converted to operate on LPG. (G31). Only the parts supplied in conversion kit# 250158 must be used. The 3.5mm injector must be installed into the inlet of the gas valve and the 5.7mm injector in to the outlet of the gas valve. Using the plastic plugs supplied the aeration holes in the white premix air box mounted on the inlet of the combustion fans must be plugged according to the table below.

Page 50

STRATA1

38 & 38/46 COMBI

19.3 control

panel

The user interfaces on the boiler control panel include a double pole on/off switch, 4Nr membrane button switches with click response, an LCD display screen with backlight and a mechanical dial type pressure gauge to indicate heating system water pressure.

The membrane button switches (with the exception of the test button) are multi-function and have varying operation depending upon the operational mode of the boiler.

When requiring to use the membrane button switches, light but firm finger pressure must be exerted on the appropriate circular marking until a click response is felt/heard.

display

The back lit LCD display screen has two lines. The normal text displayed is:-

a) Upper Line – Indicates current status of boiler, e.g. “HW DEMAND”, and either “S” (summer) or “W”

(winter) / “D” (day) or “N” (night). b) Lower Line – Indicates current flow temperature of boiler and real time.

menu/reset button

● Gives access to the various menus

● Scrolls through the current operational status

messages.

● Confirms an entry during controls programming.

● Resets the boiler following a “lockout”.

button

● Advances (Scrolls forward) through menu.

● Increases a value to be edited.

● Sets controls to either summer (heating off) or

winter (heating on) operation.

button

● Reverses (scrolls backward) through menu.

● Reduces a value to be edited

● Sets appliance (for 10 minutes) into Engineers

mode for commissioning or checking purposes.

test button

● Checks overheat safety circuit (during a burner

on mode; will cause burner to be shut down and then re-ignited).

● Checks boiler pump operation (during a burner

off mode; will cause pump to be operated at 100% speed for approx 2 seconds.

"+"

"-"

Fig 21.

Plus "+"/ Summer-Winter

Button

Display

RESET TEST

Menu / Reset Button

STATUS

Minus "-"/Engineers

Button

Test Button

On/Off

Switch

Gauge For Heating

System Water Pressure (bar)

Page 51

STRATA1

38 & 38/46 COMBI

19.4 first

firing

a) Attach a “U” tube manometer to a gas pressure

test point on the supply pipe (by installer) adjacent to the gas inlet connection on the appliance.

b) Turn on (purged) gas and electricity supplies.

c) Switch on boiler at on/off switch (see fig 21).

Screen display will show “Deaeration” and boiler pump will pulse on and off for approx 60 seconds. Following which, the boiler will revert to either standby or DHW demand (combi).

d) Press menu/reset button repeatedly until

screen display shows “Revolu…..R/S (see fig 21).

e) Press minus/engineers button twice. Screen

display will show “10 min test”. (see fig 21). Burner should ignite. (If after four attempts the burner fails to ignite, then the appliance will lockout and show “ignit fault”. Press menu/reset button. Boiler will activate “Deaeration” programme following which:remove cover screw from gas valve adjustment (2) Q min and turn adjustment screw half turn clockwise see fig 22. Now repeat operations d and e until burner ignites.

f) Check working inlet gas pressure should be

nominal 20mbar for NG or 37mbar for LPG.

g) Using the “+” and “-“ buttons adjust burner fan speed to approx 1200 Revolutions. (see fig 21).

h) Observe the colour of the burner, correct colour should be dull red. Using adjustment (2) Q min (see

fig 22), set burner at correct colour. Turning screw clockwise increases brightness; anti clockwise reduces brightness of burner. Turn the screw very slowly and just a few degrees at a time – the adjustment is very sensitive. Following this procedure will avoid poisoning your combustion analyser.

i) Remove flue gas analysis test point cap (top-front-right of combustion chamber shell) and insert probe

of combustion analyser. Adjust as necessary (2) Q min to obtain required CO

% value – see Table 10. Make adjustments slowly and wait at least 2 minutes for analyser reading to stabilise before re-adjusting. Turning (2) Q min clockwise increases CO

%. Turning (2) Q min anti-clockwise decreases CO2%.

j) Using the “+” and “-“ buttons (see fig 21) increase burner fan speed to approx 6000 revolutions.

k) Check working inlet gas pressure again – see f above.

l) Check CO

% value in accordance with values shown in table 10. If adjustment is required, then turn screw (3) Q max (see fig 22). Turning (3) Q max clockwise decreases CO

%. Turning (3) Q max anti-clockwise increases CO2%.

NOTE: Adjustment of either (2) Q min or (3) Q max will affect the other adjustment to a lesser or greater extent. Following the adjustment of either Q min or Q max, check the CO2% value at the other setting and correct as necessary.

Nat Gas G20

9.5

9.0

LPG G31

11.5

11.0

Gas Type

% at 1200 Revs

% at 6000 Revs

Table 10 Flue gas CO2% settings

gas valve

Q max

Q min

Burner offset pressure test point

Adjustments

Turning 2 clockwise increases min output & CO

Turning 3 Anti clockwise increases max output & CO2%

Fig 22.

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19.5 setting

the control panel

19.4 first firing (contd)

m) Repeat operations g, I, j and l and check/adjust settings as necessary.

n) Press “Test” button (see fig 21) to stop the burner.

o) Repeat operations d, e, g, i, j, and l and check/adjust settings as necessary. Refit (2) Q min cover screw.

p) Press “Test button (see fig 21) to stop the burner.

q) Remove analyser test probe and re-fit test point cap hand tight. Ensure rubber seal disc is in place

inside cap.

r) Turn off gas supply and remove U tube manometer from inlet pressure test point and re-fit test point

screw and tighten. Turn on gas supply and check test point for gas soundness using leak detection fluid.

NOTE: Test period expires after 10 minutes. If this period expires before or whilst adjustments are being made/completed, then return to required adjustment position by repeating d, e, etc.

s) Check operation of flame failure system by turning off gas supply and then attempt to ignite burner.

After 4 unsuccessful ignition attempts, the boiler should lockout and display “ignit fault”. Restore gas supply and press reset button.

The control panel has a number of parameters that need to be set to the requirements of the attached

system and the needs of the user. The control parameters are accessed via a scrolling menu.

● MENU/RESET Button – press and hold for approximately 3 seconds (see fig 20).

● The screen will briefly display “-MENU-“ and will then display a menu option.

● To scroll through the menu options, use the “+” or “-“ buttons, simply stop at the required option and

follow specific instructions to programme as appropriate.

menu options

1. party

This is a user function and allows the user to extend normal heating operation (on an as and when

required basis) beyond the normal heating period.

To access the “Party” option press the “Menu” button once. “——— hours” will flash on the screen, press “+” or “-“ to enter a value and then press “Menu” to confirm the entry. Range 0 to 24 hours. Default 0 hours.

2. temp DHW

This is a user function and allows the user to programme the required stored hot water temperature where the boiler is serving a hot water cylinder (not combi boiler) and where the temperature control is via a sensor. If temperature control is via a cylinder thermostat then this function is not operative.

To access the “TEMP DHW” option press the “Menu” button once. “———°C” will flash on the screen, press “+” or “-“ to raise or lower the value and then press “Menu” to confirm the entry. Range 4060°C. Default 60°C.

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3. day temperat (day temperature)

This option is only displayed when the outside air temperature sensor (supplied with the boiler) is

installed and operation with direct-on-boiler weather compensated flow temperatures is required.

This is a user function and allows the user to raise or lower the room temperature for adjustment of

the comfort level.

Raising or lowering the set value will cause parallel displacement of the heating slope line which will

result in raising or lowering of the heat emitter temperatures.

The default value for this setting = 20°C.

4. day/time

This is a user function and at this option the real day of the week and time should be set.

To set clock:a) Press “Menu” button b) Use “+” or “-“ to set day c) Press “Menu” button d) Use “+” or “-“ to set hour (24 hour clock) e) Press “Menu” button f) Use “+” or “-“ to set minutes g) Press “menu” button to effect settings.

5. set CH timer

This is a user function and at this option the on/off times for normal heating may be set. 3 ON and 3

OFF Periods may be set each day.

IMPORTANT: If the heating circuit is being controlled by a remote timeswitch or BMS system then the

1st on time must be set to 0000 and the 1st off time must be set to 2400 for each day.

To set operational times:a) Press “Menu” – “Monday >” is displayed on screen. b) Press “Menu” – “Copy SU>MO” is displayed on screen, (ignore this) c) Press “+”, “Switch on 1” is displayed on screen d) Press “Menu” – (hours will flash) use “+” or “-“ to set required hour e) Press “Menu” – (minutes will flash) use “+” or “-“ to set required minute f) Press “Menu” to confirm settings g) Press “+”, “switch off 1” is displayed on screen h) Repeat d to f input 1st switch off time. i) At this point, press either “+” to programme 2nd heating period, in which case, repeat d to h for 2nd

period, and then if 3rd heating period is required, repeat c to h for 3rd period or press “+” until “<back” is displayed, then press “Menu” to advance to next day.

j) At this point, press either “Menu” to copy programme to next day or press “+” to allow individual day

programming. If individual day programming is required then repeat d to j as appropriate.

k) Continue programming/copying each day until each day has been programmed ending with Sunday and

screen display “<Back”.

l) Press “Menu” to return to main menu.

Default setting – on 0.600 – off 23.00

6. set HW timer

This is a user function, and at this option the on/off times for hot water production may be set. NOTE: This function is not appropriate to the Combi boiler and may be ignored. Hot water production

with the combi boiler is instantaneous and is available at all times.

Hot water production always takes priority over heating and the heating function will be temporarily suspended whilst hot water is being generated. This applies to both the Strata 1-38 boiler and Strata 1-38/46 Combi.

To set operational times for hot water charging follow the procedure as described in 19.4.5 a to l. Default – on 0.600 – off 23.00.

19.5 setting the control panel (contd)

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7. set MV timer

This is a user function and at this option, the on/off times for an under floor coil circuit (that is

controlled by an MR03 mixing valve regulation control box from MHS Boilers) may be set.

To set operational times for under floor circuit operation, follow the procedure as described in 19.4.5

a to l. Default on 0.600 – off 23.00.

8. setback

This is a user function and sets the reduction in room temperature for overnight operation. This is a

reduction in temperature from that which is set in 19.4.3 – Day temperature. Default value 5°C.

To programme set back temperature:a) With “SETBACK” displayed on the screen press “Menu”. b) “___°C” will flash on the screen, press “+” or “-“ to raise or lower the value to the required setting

and then press “Menu” to confirm the entry.

9. holiday

This is a user function and allows up to 255 days of holiday period to be programmed. During this period the heating will operate (if in winter mode) at “setback” temperature see 19.4.8 and

the domestic hot water will be maintained at a minimum of 20°C.

After the number of “holiday” days has expired, the unit will revert back to the normal operation.

NOTE: If the heating circuit is being controlled by an RE2132 modulating room unit, then this piece of control equipment should also be “holiday” programmed. See instructions supplied with the RE2132 unit. Default setting 0 days.

To programme a holiday period:a) With “holiday” displayed on the screen press “Menu”. b) “___days” will flash on the screen press “+” or “-“ to input the required number of days in the holiday

period and then press “Menu” to confirm the entry.

The holiday period should be programmed on the day that the holiday begins.

10. installer

This function should not be accessed by the user and is code protected. For Installer programming instructions see 19.6.

11. back

This is the end of the menu. Press “Menu” to exit.

19.5 setting the control panel (contd)

19.6 installer programming

of control panel

A number of operational options are available to the installer. These can only be accessed by means of a pass code. If the correct code is entered at 19.4.10 then the following parameters may be set, see 19.5.2.

(For installer code no see bottom right hand corner of page).

1. to enter installer programming menu:-

a) With “INSTALLER>” displayed on the screen press “Menu”. b) Code: 0 will flash on the screen press “+” or “-“ to input the installer code and then press “Menu” to

confirm the entry and access the installer menu.

2. installer programme menu

Scroll through menu using “+” or “-“ buttons. The current setting for any parameter will be displayed

under the particular parameter title.

✁

Installer

Code

= 21

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a) CURV 20°C CH (Default setting = 0°C)

This option is only displayed when the outside air sensor is installed for direct on boiler weather

compensation.

Shift adjustment of the weather compensated flow temperature (if active – see 19.5.2l) at +20°C

outside air temperature.

At this setting, the installer may add or subtract up to 20°C to or from the factory set 20°C flow temperature. In other words, the flow temperature at outside air temperature 20°C may set between 0°C and 40°C. See figs 22-25.

To make an adjustment:-

Press “Menu” button once, the current setting will flash on the screen, press “+” or “-“ to input a new value between –20°C and +20°C and then press “Menu” button to confirm the entry.

NOTE: Settings a and b are only relevant if the supplied outside air temperature sensor has been installed and “outside air control” selected in 19.5.2l.

b) CURV –1°C CH (Default setting = 0°C)

This option is only displayed when the outside air sensor is installed for direct on boiler weather compensation.

Shift adjustment of the weather compensated flow temperature (if active – see 19.5.2l) at –1°C outside air temperature.

At this setting, the installer may add or subtract up to 20°C to or from the set maximum central heating flow temperature. (the base setting for the maximum central heating flow temperature is made in 19.5.2l)

NOTE: The maximum flow temperature is 85°C. If a shift adjustment is made that asks for 85°C to be exceeded, the curve will flatten at flow temperature 85°C but the result will be, that the maximum flow temperature of 85°C will be achieved at a higher outside air temperature. See figs 22-25.

To make an adjustment:-

c) PUMP MIN (Default setting = 35%)

Setting for the lowest (minimum) speed that the inbuilt modulating speed pump can operate at. Recommended setting 35%.

To make an adjustment:-

Press “Menu” button once, the current setting will flash on the screen, press “+” or “-“ to input a new value between 35% and “PUMP MAX” and then press “Menu” to confirm the entry.

d) PUMP MAX (Default setting = 100%)

Setting for the highest (maximum) speed that the inbuilt modulating speed pump can operate at. Recommended setting 100%.

To make an adjustment:-

Press “Menu” button once, the current setting will flash on the screen, press “+” or “-“ to input a new value between “PUMP MIN” and 100% and then press “Menu” to confirm the entry.

e) SERVICE IN

The control panel includes a countdown service timer and at this setting will initially show the number of days left until the boiler should be serviced and at which time the screen display will show exclusively “Service”. The boiler will continue to function but the user should arrange for a service visit.

To reset the service counter to the default value of 365 days press “Menu” button twice. If another value between “off ” (service counter inactive) and 1500 days (Recommended setting not greater than 365 days) is required, then press “Menu” button once, input a new value using either the “+” or “-“ buttons and then press “Menu” to confirm the entry.

f) PUMP CONTINUE (Default setting = off)

At this setting, the inbuilt pump and any connected external pump may be operated continuously during winter mode. Recommended setting = off.

To alter the setting:-

Press “Menu” button once, press either “+” or “-“ to alter the setting to “on or off ” and then press “Menu” to confirm the entry.

19.6 installer programming (contd)

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19.6 installer programming (contd)

g) ECO + (Default setting = on)

The inbuilt modulating speed pump will automatically modulate in order to maintain the design 20°C

∆t across the boiler flow and return temperatures.

If “ECO+” is set to “off ”, the pump speed is free to modulate at any return water temperature with

the exception of the first start-up in the morning.

To alter the setting:Press “Menu” button once, press “+” or “-“ to input the required setting and then press “Menu to

confirm the entry.

h) POSTRUN HW (Default setting 1 min)

At this setting the post running time (overrun) of the inbuilt boiler pump and any connected HW primary charging pump may be set. The pump/s will overrun for the set time at the end of a HW demand period.

This setting is only applicable for Combi boilers, and standard boilers serving a domestic hot water cylinder or calorifier. Recommended settings:

Combi boiler = 1 minute

Model 38 boiler = Not less than 1 minute

To alter the setting:-

Press “Menu” button once, the current setting will flash on the screen, press “+” or “-“ to input a new value between 1 and 5 minutes and then press “Menu” to confirm the entry.

i) POSTRUN CH (Default setting 3 min)

At this setting the post running time (overrun) of the inbuilt boiler pump and any connected CH circulation pump may be set. The pump/s will overrun for the set time at the end of a CH demand period.

Recommended setting = not less than 3 minutes.

To alter the setting:-

Press “Menu” button once, the current setting will flash on the screen, press “+” or “-“ to input a new value between 3 to 20 minutes and then press “Menu” to confirm the entry.

j) MIN POWER (Default setting 17%)

This is the minimum power for both central heating and hot water demands that the burner may modulate down to.

Recommended setting = not less than 17%.

To alter the boiler minimum power:-

Press “Menu” button once, the current setting will flash on the screen, press “+” or “-“ to input a new value between 17 to 100% and then press “Menu” to confirm the entry.

k) MAX POWER CH (Default setting 100%)

At this setting, the maximum output of the boiler for a central heating demand may be set. This adjustment is only relevant to those market places where national or local regulations demand that a boiler must be accurately set to meet design load.

The Strata 1-38 and 38 combi boilers are fully modulating appliances and automatically adjust to suit load conditions and for the UK market it is recommended to leave the setting at 100%.

To alter the boiler maximum CH power, press “menu” button once, the current setting will flash on the screen, press “+” or “-“ to input a new value between “Min Power” and 100% and then press “Menu” to confirm the entry.

l) FUNCTION NR (Default setting = 9)

At this setting the boiler is programmed to suit the needs of the attached system.

Select the appropriate “Function No” from the following tables and then enter the required number.

To input “Function No”:-

Press “menu” button once, the current setting will flash on the screen, press “+” or “-“ to input the appropriate number and then press “menu” to confirm the entry.

NOTE: Take care to enter the correct function number as relevant to the system configuration. Entry of an incorrect function number may result in an error (fault) message being displayed on the control panel screen and or incorrect or unwanted operation of the boiler and system.

m) <BACK

To exit the installer menu, press “menu” button twice when screen display shows “<back”.

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19.6 installer programming (contd)

System Type Room Controls Type

CH Flow Function Temperature Number

Outside air temperature controlled, With RE2132 modulating room unit Max 55°C1 without a secondary underfloor Max 70°C2 mixing circuit Max 85°C3

With room thermostat/volt free switch Max 55°C4

Max 70°C5 Max 85°C6

Without room controls Max 55°C7

Max 70°C8 Max 85°C9

Outside air temperature controlled, With 2Nr RE2132 room units Primary 70°C10 with a secondary underfloor Primary 85°C11 mixing circuit and MR03 controller With 1Nr RE2132 modulating room unit Primary 70°C12

Primary 85°C13

With room thermostat/volt free switch Primary 70°C14

Primary 85°C15

Without room controls Primary 70°C16

Primary 85°C17

No outside air temperature control, With RE2132 modulating room unit Max 55°C18 and without secondary underfloor Max 70°C19 mixing circuit Max 85°C20

With room thermostat/volt free switch Max 55°C21

Max 70°C22 Max 85°C23

No outside air temperature control, With 2Nr RE2132 modulating room units Primary 70°C24 and with secondary Underfloor Primary 85°C25 mixing circuit and MR03 controller With 1Nr RE2132 modulating room unit Primary 70°C26

Primary 85°C27

With room thermostat/volt free switch Primary 70°C28

Primary 85°C29

Fixed constant flow temperature with no outside air temperature control and without room controls.

Without secondary underfloor mixing circuit Max 55°C30

Max 70°C31

Max 85°C32 With secondary underfloor mixing circuit Primary 70°C33 and MR03 controller Primary 85°C34

Table 11

Valid for Combi boilers and standard boilers where primary hot water control is via a 3 way

divertor valve.

Table 12

Valid for combi and standard Strata 1-38 boilers. Multiple boiler installation with boilers controlled by

a cascade manager.

System Type

Function

Number KKM2 Modulating Kaskade Manager 35 Analog cascade manager with signal 0-3v or 0-10v* 36

* Boilers must be fitted with optional extra 0-10v interface

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19.6 installer programming (contd)

Table 13

Valid for standard Strata 1-38 boilers only (NOT COMBI) where the domestic hot water cylinder (if fitted) is charged via an additional hot water primary pump and the pump is electrically connected to the boiler.

glossary of terms

Outside Air Temperature The (supplied) outside air temperature sensor has been installed and Controlled direct-on-boiler weather compensated flow temperature is required.

Max Maximum flow temperature either fixed or weather variable.

Primary Maximum flow temperature either fixed or weather variable with reference

to the boiler supply side of an under floor coil mixing valve and any primary radiator zone.

RE2132 Modulating Intelligent (time and temperature) room controller from MHS Boilers. For Room Unit specific details see either Technical Sales Literature or specific

installation/user guide.

MR03 Controller Interface control box giving the ability for the boiler to control the space

temperature and coil temperature of an under floor heating coil zone.

System Type Room Controls Type

CH Flow Function Temperature Number

Outside air temperature controlled, With RE2132 modulating room unit Max 55°C 37 without a secondary underfloor Max 70°C38

mixing circuit Max 85°C39

With room thermostat/volt free switch Max 55°C 40

Max 70°C41 Max 85°C42

Without room controls Max 55°C43

Max 70°C44 Max 85°C45

Outside air temperature controlled With 2Nr RE2132 modulating room units Primary 70°C46 with a secondary underfloor Primary 85°C47 mixing circuit and MR03 controller With 1Nr RE2132 modulating room unit Primary 70°C48

Primary 85°C49

With room thermostat/volt free switch Primary 70°C50

Primary 85°C51

Without room controls Primary 70°C52

Primary 85°C53

No outside air temperature controls With RE2132 modulating room unit Max 55°C54 and without secondary underfloor Max 70°C55

mixing circuit Max 85°C56

With room thermostat/volt free switch Max 55°C 57

Max 70°C58 Max 85°C59

No outside air temperature controls With 2Nr RE2132 modulating room units Primary 70°C60 and with a secondary underfloor Primary 85°C61 mixing circuit and MR03 controller With 1Nr RE2132 modulating room unit Primary 70°C 62

Primary 85°C63

With room thermostat/volt free switch Primary 70°C64

Primary 85°C65

Fixed constant flow temperature with no outside air temperature control and without room controls.

Without secondary underfloor mixing circuit Max 55°C66

Max 70°C67

Max 85°C68 With secondary underfloor mixing circuit Primary 70°C69 and MR03 controller Primary 85°C70

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default compensation slope

Max Flow Temperature

Boiler Flow Temperature ºC

Outside Air Temperature ºC

Boiler Flow Temperature ºC

Outside Air Temperature ºC

range of parallel displacement of slope A

When compensation required outside sensor must be installed and appropriate function No. selected.

Slope A - Max/Primary 85°C

Slope B - Max/Primary 70°C

Slope C - Max 55°C

19.6 installer programming (contd)

Fig 22.

Fig 23.

-20 -15 -10 -5

CURV -1ºC CH

-20 +20

+5 +10 +15 +20 +250

-1

-20

-15 -10 -5

-1

default

+20

-20

+5 +10 +15 +20 +250

CURV 20ºC CH

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Boiler Flow Temperature ºC

Outside Air Temperature ºC

Boiler Flow Temperature ºC

Outside Air Temperature ºC

range of parallel displacement of slope B

range of parallel displacement of slope C

19.6 installer programming (contd)

Fig 24.

Fig 25.

-20

-15 -10 -5

CURV -1ºC CH

-20 +20

+5 +10 +15 +20 +250

-1

default

+20

-20

CURV 20ºC CH

-20

-15 -10 -5

CURV -1ºC CH

-20 +20

+5 +10 +15 +20 +250

-1

+20

-20

CURV 20ºC CH

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19.7 output for

charging hot water

20.0 setting the boiler

to work

There is no adjustment necessary or possible, as the boiler controls are self learning and will self adapt the optimum output to hot water according to the heat transfer capabilities of the connected hot water calorifier or cylinder, or the rate of hot water usage (combi boiler).

WARNING: This appliance must not be left to operate with the outer casing removed.

1. To fit casing to boiler ensure hooks on top rear edge of boiler case engage properly into rear chassis

assembly. Latch bottom case fixings and tighten central locking screw.

2. Turn ON on/off switch and set any external controls to auto operation.

3. With boiler operating (burner on) press “Test” button on boiler control panel to test overheat controls

in the boiler. The boiler must shut-down and then re-ignite.

4. Before handing over the appliance to the user, check again and clean strainers/filters.

21.0 servicing

instruction

21.1 inspection

general

In general, maintenance/inspections should take place:

a) When the display on the unit indicates that inspection is required (status shows “SERVICE”) normally

after 365 days.

or b) At least every 12 months.

Before carrying out any maintenance the unit must be inspected.

a) Ask the user about any problems with the boiler unit or any other comments. b) Check the water pressure of the installation. c) Remove the casing of the unit and inspect all pipes and connections for water leaks. d) Inspect the top of the casing and/or the top of the heat exchanger for water leaks or signs of water

from the flue air supply tube. e) If you have a notebook computer, connect it and check the service page for any errors, messages, starts

and successful restarts. (Special communication lead and service software required) f) Run the unit at maximum capacity and measure the input and the CO

g) Run the unit at minimum capacity and measure the input and the CO

h) Listen to the sound of the in built pump.

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21.1 inspection (contd)

i) Turn off the boiler and disassemble the burner by removing the six M6 nuts around the burner door,

removing the ignition cable and pulling the burner forwards. When the burner has been pulled forwards to halfway across the burner area, the plug on the fan cable must be removed from the fan motor. Check the interior of the heat exchanger.

j) Open the syphon cleaning rinsing point at the base of the unit with suitable receptacle below to collect

syphon contents. Refit rinse point cap after flushing. k) Disassemble the plastic box at the suction side of the fan, inspect the fan blades. l) Check the distance between the electrode and the burner earthing rod; this should be 4 to 5 mm. m) Check water treatment dosage level.

21.2 maintenance

Depending on the results of the inspection, carry out any maintenance and if necessary any preventive maintenance. Possible actions following inspection (21.1) include:

at a) The remarks and comments of the client must be taken seriously and the cause(s) of any faults or

problems must be found.

at b) The pressure of the installation must be between 1 and 2 bar when hot (not less than 0.5 bar cold):

any possible leaks in the system must be identified; if necessary, have a pipework engineer solve the problem.

at c) Possible leaks or weeping must be resolved immediately.

at d) In case of water leakage or ingress from the air supply pipe, the cause must be found and rectified.

at e) Draw your conclusions from the service screen of the service software program (available from

MHS Boilers spares department) and attend to those parts that have caused any faults.

at f ) and at g)

If necessary, adjust the gas setting on the gas valves.

at h) If the in built pump makes an un-natural noise, and in particular if the pump is more than 5 years

old, it is recommended that the pumps should be replaced by way of preventive action.

NOTE: The pump is modulating and does have characteristic “yet yet” noise which is normal at low speeds.

at i) NEVER CLEAN THE BURNER ITSELF.

If the interior of the heat exchanger is contaminated and/or there is a deposit on the surfaces of the coiled stainless steel pipes, the latter must be removed with a natural bristle brush. Strata heat exchanger cleaning granuals can be obtained from MHS Boilers spares department. (DO NOT USE A STEEL BRUSH !) Then remove any dirt with a vacuum cleaner.

at j) The syphon must be rinsed. With the burners removed, use a filling hose to insert water into the

heat exchanger, which will automatically reach the siphon. Allow the water to run clear prior to refitting the rinse point cap.

at k) If dirt has deposited on the fan blades, each blade must be carefully cleaned, until the blade material

is visible again. If this is not done evenly the fan will not rotate properly and be out of balance.

at l) Carefully bend the electrode without touching the burner, until the correct distance has been

reached. Adjust only the angle of the bend nearest the ceramic insulator. Do not use tools. Firm finger pressure is all that is required.

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21.2 maintenance (contd)

at m) check and top up as necessary water treatment to required %.

Important Note

IF ANY WATER CARRYING JOINT WITHIN THE BOILER IS DISASSEMBLED THEN THE “O” RING SEAL MUST ALWAYS BE REPLACED, LIKEWISE IF ANY OTHER SEAL IS NOTED TO BE DEFORMED THEN THEY SHOULD ALSO BE REPLACED. WATER SEALING “O” RINGS ARE A ONE TIME USE ONLY AND SHOULD NOT BE RE-USED.

cancelling the “service” message

Following the maintenance operations, the service message (when displayed) must be cancelled See 19.6).

22.0 screen display/

diagnosis of faults

The control panel of the Strata 1 boiler has an LCD screen, displaying two lines of data. This screen provides information about the operation of the appliance; it shows operation messages (non flashing) and fault messages (flashing display). The first line contains text information about the status of the unit.

It shows:

status messages (non flashing) for normal operation

No Demand No heat demand (boiler not required to be on).

Pre-purge Combustion chamber is being pre-ventilated with air from the burner fan.

Ignition The ignition sequence of the burner is initiated.

CH Demand The boiler is operating in central heating mode.

HW Demand The boiler is operating to produce domestic hot water.

Chimney The boiler is operating in test mode at mid output to enable flue gas emissions to be

checked (auto expires after 10 min).

10 min Test The boiler is operating in engineers test mode for adjustment purposes (auto expires

after 10 min).

Post-Purge Combustion chamber is being post-ventilated with air following boiler operation.

Limit F/R The flow and/or return temperature is too high (currently).

Fan High The burner fan is running too fast (currently).

Fan Low The burner fan is running too slow (currently)

Fault R/U There is a fault with the modulating unit (RE2132) or kascade manager (KKM2) or a

fault in the wiring to these controls (in the case of the RE2132 the boiler runs continuously in heating mode to protect the building).

OTS Fault There is a fault in the outside air sensor or in the wiring to the sensor or the function

Nr is incorrectly set to ask the boiler to look for an outside sensor when there is none installed.

Service The service interval time has expired and the boiler should now be maintained.

Deaeration The in built pumps are operating to remove any possible collection of air from the heat

exchanger. (Occurs when power turned off/on and after reset of fault).

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22.0 screen display/diagnosis of faults (contd)

The second line of text displays values such as temperature, percentages etc and the reset button may be used to scroll through (for information) the values of the various sensors that are/may be connected in the boiler plus fan speed and pump speed etc.

status messages (flashing display) indicating a fault

A flashing display indicates a fault and that the boiler has shutdown (lockout). The boiler will not attempt to operate until the “red” reset button is pressed.

Any repetitive flashing fault message should be investigated, the cause found and corrective action taken. For each flashing display message there is a possible cause, see list of cause numbers following the “flashing status” list.

Display Message Meaning Cause Number/s Flashing

STB-Supply Heat exch high limit stat has tripped. 5, 6, 7, 8, 21, 24, 25, 26, 31, 36

STB-Flue Gas Flue limit stat has tripped. 2, 5, 6, 7, 21, 24, 25, 31, 36

Fan Spd high Burner fan speed is too high. 9, 11, 29, 31, 33

Fan Spd low Burner fan speed during pre-purge is too low. 9, 10, 11, 14, 18, 29, 31, 33

Fan Spd oper Burner fan is detected as 4, 11, 29, 31

operating when should be idle.

Ignit Fault Ignition to burner has not 11, 12, 13, 15, 16, 17, 19, 22,

been successful after 4 attempts. 23, 27, 29, 30, 31, 35, 37, 38

No Flame Flame at burner has been lost on 13, 15, 16, 17, 20, 22, 23

4 consecutive occasions during operation.

False Flame Flame is detected at the burner when 17, 19, 30

there should be no flame.

S1 Disconnect Heat exch flow temperature sensor interrupted. 3, 5, 33

S3 Disconnect Combi boiler - hot water flow 3, 5, 33

temperature sensor interrupted.

S4 Disconnect Return temperature sensor interrupted. 3, 5, 33

S7 interrupt Mixed flow temperature sensor interrupted. 1, 3, 5, 33

Only when MR03 unit installed.

Program end Follows reprogramming of control panel with

laptop PC, not a fault - just press reset button.

Gas valve High resistance in the electrical circuit to 26, 28, 29, 31, 33, 37

and including the gas valve is detected.

Soft W Fault Error in software in the control. 29

Display Message Meaning Cause Number/s Flashing

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22.0 screen display/diagnosis of faults (contd)

Reset Key There is a fault with the reset button. 29, 31, 34

Eeprom There is a fault in the EEPROM in the control. 29

Intern Fault There is an internal fault in the control panel.

Test Fault There is a fault with the test button. 29, 31

22.1 (possible) causes of fault

& corrective action

Cause No. Reason/Action

1. Operational function No. not set correctly / Check and correct settings. See tables 11, 12, 13.

2. Unsound electrical connections to flue limit stat / Check and correct.

3. Sensor not correctly connected or sensor defective/Check connections and or replace sensor.

4. Short circuit in wiring / Check and rectify.

5. Short circuit in wiring to sensor / Check and rectify.

6. Boiler pump not rotating (seized or defective)/Free seized shaft or if defective replace pump.

7. System lacks water / Investigate, refill and vent.

8. Connections to heat exchanger limit stat unsound /check & rectify.

9. Unsound electrical connection to fan / Check integrity of fan connection plug.

10. Fan blades heavily contaminated / Clean fan.

11. Fan is defective / Replace fan.

12 . There is no gas supply available / Investigate, restore gas supply.

13. Low gas pressure / Investigate and rectify.

14. Fuse defective / Check fuses and replace as necessary.

15. Gas valve min output setting is incorrect / Check and adjust min output CO

16. Oxidation on burner mounting screws / Loosen and retighten screws.

17. Poor ignition lead connection to electrode or damp connection or lead damaged and shorting to earth / Check and rectify.

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Cause No. Reason/Action

18 . Transformer defective / Replace transformer / loose connection.

19. Condense siphon is blocked or condense waste blocked or frozen / Clear siphon or waste pipe.

20. Flue gas leakage from connection at rear of heat exchanger / Check, reposition or replace seal.

21. System strainer blocked ?, isolation valve closed ? Or some other interruption to water flow / Check and rectify.

22. Unacceptably high resistance in flue or air supply tubes or flue blocked / Check flue for suitability or clear obstruction.

23. Leakage of flue gas from flue gas tube into air tube vitiating the combustion air / Strip out flue system and remake joints.

24. Zone pumps not running / Check and rectify.

25. Heat exchangers fouled internally with silt or scale / Clean, descale heat exchangers and system and re-dose system with water treatment.

26. Heat exchanger high limit stat defective / Replace limit stat.

27. Boiler set for wrong gas type / Convert boiler to burn the gas being supplied.

28. Flue gas limit stat defective / Replace limit stat.

29. Boiler control panel defective / Replace control panel.

30. Incorrect position of ignition electrode / Reset gap 4-5mm.

31. moisture in-on electrical connections or components / Dry carefully using warm air from a hair dryer.

32. Incorrect electrical connection / Check and rectify.

33. Wiring interrupted (broken wire) / Check and rectify.

34. reset button stuck / Press button in attempt to free sticking contacts. If no success then replace control panel.

35. Ignition electrode damaged or broken / Replace electrode.

36. Unsound electrical connections to pump / Check and rectify.

37. Gas valve defective / Replace gas valve.

38. Reversed polarity on incoming power supply.

22.1 (possible) causes of fault (contd)

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23.0 instructing

the user

The installer should inform the user about the operation and use of the Strata 1 boiler and in particular

point out:-

● Any safety provisions.

● The need to carry out regular maintenance when the screen display shows a “SERVICE” message.

The installer must provide the user with all documentation relating to the Strata 1 boiler and any

ancillary items.

23.1 to turn on

the appliance

23.2 to turn off

the appliance

1. Ensure the manometer indicates a pressure within the system of not less than 0.5bar.

2. Ensure the gas supply is turned on.

3. Switch on the on/off switch on the appliance control panel.

4. If all controls connected to the appliance are calling for heat the screen with display DHW demand or CH demand.

5. If all controls are in the off position the screen will display standby.

6. Allway check the setting of the summer/winter switch marked with

1. Switch off the on/off switch on the appliance control panel.

2. Turn off the gas supply.

NOTE: Turning off the appliance will leave the system at risk of freezing during winter months and will put out of action the automatic pump exercising routine. If the only reason for shutdown is that normal heating is not required, then it is recommended to leave the boiler on and turn off or turn down any external controls.

"+"

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24.0 parts list

Strata 1 38 parts 1

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STRATA1

38 & 38/46 COMBI

24.0 parts list

(contd)

Strata 1 38 parts 2

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STRATA1

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24.0 parts list

(contd)

Strata 1 38 parts 3

Page 71

QW/0102/4576

35 Nobel Square, Burnt Mills Industrial Estate, Basildon, Essex SS13 1LT Tel: 01268 591010 Fax: 01268 728202

www.mhsboilers.com

This publication is issued subject to alteration or withdrawal without notice.

The illustrations and specifications are not binding in detail. All offers and sales are subject to the Company's current terms and conditions of sale.

A member of the Modular Heating Group Plc

MHS Boilers STRATA1, STRATA1 38, STRATA1 38 COMBI, STRATA1 46 COMBI Instructions Manual

Specifications and Main Features

Frequently Asked Questions

User Manual