Hoval SR-plus 600, SR-plus 700, SR-plus 1500, SR-plus 1750, SR-plus 2000 Operating And Installation Instructions

Issued By TECHNICAL DEPT

Dated: August 2014 Approved KS

Operating and Installation

Instructions for the SR-plus

hot water boiler

0088

2

Contents

Page

Material in this publication may not be reproduced without the company's written permission.

Hoval reserve the right to change specications without notice.

Hoval Ltd, Northgate, Newark, Notts, NG24 1JN, Tel: [phone] Fax: [phone] e-mail: [e-mail]

Table of Contents

Introduction

Gas Safety(Installation & Use)

Sample Nameplate

Delivery, Ofoading , Storage.

Description of the SR-plus boiler

Technical & Performance Details

Installation

-Space requirements

- Noise levels

-Ventilation,

-Open Vented & Pressurised Systems

-Flues & Chimneys

-Filling the system with water/ water treatment

-Burner matching , Fitting the Burner

- Water ow & return temperatures

- Control details

- Boosters

Commissioning

Operating Instructions, including sequencing of boilers under BMS control

Maintenance

- Inspection & Servicing

- Boiler & Burner Servicing

- Summer Shutdown

- Burner Maintenance

Oil Burner Fault Finding Chart

Gas Burner Fault Finding Chart

3

4

4

4

5

6-8

9-15

9

9

10

10

11

12

13

13

14

15

16-17

18

19-22

19

20-21

21

22

23-24

25-26

IMPORTANT

These instructions should be read and understood before attempting to install, commission or oper-

ate this unit. The boiler has been tested to comply with the Gas Appliances Directive (90/396/EEC) &
the Boiler Efciency Directive (92/42/EEC) Certication No. CE-0085 .

August 2014

3

Introduction

Introduction

These instructions have been written to give a brief description of the SR-plus hot water boilers, their

installation, commissioning, operation and subsequent maintenance.

The installation of boilers and their ancillary equipment is normally carried out by the Heating Engineer, and

for the purpose of this manual he / she is regarded as the installer, and, as such, it is his / her responsibility

to ensure that he / she has read and understood the contents of this manual before installing the boiler.

It is essential that each boiler has all services connected to it before commissioning.

A note should be entered below by the person responsible for the plant, giving the boiler model,
output, reference 'K' number, and burner reference number. These numbers are indicated on the
appropriate nameplates.

For completion by Plantroom Attendant

Boiler Model: Burner Ref. No.

Output (kW): Fuel:

K No. Commissioning Date

For technical, servicing or parts enquiries,

telephone, fax or e-mail to Hoval

quoting the boiler(s) serial number, as above

The installation should be in accordance with current

I.E.E. Regulations, relevant British Standard and Codes of

Practice, Building Regulations and Local Authority Bylaws.

Hoval Engineers will normally commission the boiler and

if the heating engineer is present at the time, he will be

instructed on the day-to-day operation of the boiler. If this

is not possible, or additional training is required, this can be

arranged through Hoval.

The boiler combustion gures are recorded on the commis-

sioning report and a copy of this will be issued for retention

with this manual (see example).

Commissioning/Combustion Report

August 2014

4

Delivery, Ofoading & Storage

Boilers and associated equipment are normally delivered by our own transport on a mutually agreed
date. The boiler can be ofoaded by the crane lorry if specically booked at the time of ordering.
Adequate lifting points are provided on the boiler shell.
All boilers are delivered tted with casings and control panel complete with ying lead.

On delivery, the installer should check all items against the delivery note and should then store them
in a safe and dry place.

NOTE:

There are other small items such as ceramic strip packing, cleaning tools and safety

valves which are transported in the boiler combustion chamber.
These should be removed, checked and stored also.

Gas Safety (Installation and Use) Regulations '98.

It is the law that all gas appliances are installed by a CORGI registered installer in accordance with the above
regulations. Failure to install appliances correctly could lead to prosecution. It is in your own interest, and that
of safety, to ensure that the law is complied with.

The Hoval SR-plus range, with both standard and low NOx burners, have been Certied against the requirements
of prEN676 for natural gas.

The installation of the boiler must be in accordance with relevant British Standards, the Gas Safety Regulations,
Building Regulations, I.E.E. Regulations and the by laws of the local Water Authorities. A at level re proof
oor should be provided and the location should permit the provision of a satisfactory ue system and adequate
air supply.

Gas Safety, Nameplate & Delivery

General

BS6644 Installation of Gas Fired ...
BS6880 LowTemperature Hot Water
CP342:2 Centralised Hot Water Supply

Hoval

Hoval, Northgate, Newark, Notts, NG24 1JN Tel: [phone]

Boiler Type
K number Year

Output (gas/oil) kW Input (gas/oil) kW

Maximum Minimum
Heat Output kW Output Gas Oil

Flue Temp (gas/oil)

o

C kW
kW
Pressurised Vented
Operating temperature

Oil Min

o

C Maximum oC

Gas Min

o

C Maximum oC

Efciency class

NOx rating
Working Test
Pressure(max) bar Pressure bar
Electrical connection

3N-/50Hz 400/230 v Power input

Maximum A

PI Number:0085 AQ 0670

0088

This appliance must be installed in accordance with the rules in force and used only in a suf­ciently ventilated space. consult insrtuctions before installation and use of this appliance

Sample nameplate

British Gas Publications

IGE-UP-1 Soundness testing and purging of industrial
and commercial gas installations.
IGE-UP-2 Gas installation pipework, boosters and
compressors on industrial and commercial
premises.
IGE-UP-10 Installation of gas appliances in industrial
commercial premises. Part 1: Flued
Aplliances.

August 2014

5

Description of the SR-plus boiler

Description of the SR-plus boiler

Applications

These boilers are intended for heating commercial and

industrial premises within the limits of temperature and

pressure stated in this manual. They may also be used

to supply D.H.W. to such premises in conjunction with
an indirect calorier.

Benets & Features

• UK design & manufacture

• W h e r e a p p l i c a b l e f u l l c o m p l i a n c e w i t h t h e P r e s s u r e
Equipment Regulations.

• no minimum ow rate

• compact, space saving design

• standing losses less than 0.4%

• nett efciency to 91.6%

• suitable for operation with a range of
matched burners for use with oil, gas or dual fuel

General Details

The boilers are of mild steel welded construction in

which the outer shell forms a water space around the

combustion chamber.

The third pass water jacketed gas passage ways with

turbulators provide an effective secondary heating

surface. Flue gases pass to a rear mounted ue outlet

box and horizontal ue outlet. The ue outlet has a

spigot/ange for connecting to the installers ue pipe,

and is tted with a door for cleaning and access.

The SR-plus is tested and manufactured to European

boiler design codes and is offered in outputs from

500 to 4150KW. The boilers are suitable for working

pressures up to 6 bar and operating temperatures to

a maximum of 100 °C.

General

The maximum operating temperature is governed

by the pressure available at the highest point of the

system. Take the 17oC anti-ash margin from the

saturated temperature of steam at that pressure to nd

the maximum operating temperature.

Door Hinging

The hinged side door nuts are supplied with a locknut

at the back of the door boss. Hoval should be advised

of the door and gas burner handing when the boiler is

ordered or at the very earliest date.

For installation space requirements and for changing

door hinging see page 9.

On request

- ue gas thermometer

- separately mounted altitude gauge

- boiler door hinged on left hand side

- volt free contacts for B.M.S.

- hours run meter

- Modulating controller

Insulation / Cladding

100mm mineral bre wrap with woven aluminium

surface around boiler shell, complete with Hoval red

cladding panels.

Electrical Power Supply

A single phase 230V supply is required for the control panel operation. Single phase burners are electrically

supplied via the control panel. Three phase burners require a separate three phase isolated supply (by the

installer) direct to the burner, incorporating a exible connection to allow for boiler/burner door opening. In
this case control cables tted with wieland plug/socket will still run between the control panel and the burner.
All power supplies to the boiler/burner/other associated equipment (ie: gas booster, separate oil pump, etc.)
should be isolated via the same switched isolator.

Operation

Normal operation is fully automatic in conjuction with a

simple time switch or other form of control i.e. BEMS

August 2014

6

SR-plus Technical & Performance Details

(1) Based on a maximum limit thermostat setting of 110

o

C.

(2) Boiler efciencies at 100% load are based on a mean operating temperature

of 70

o

C, at 30% efciencies are based on a mean temperature of 50oC.

(3) Based on gross CV 38.5 MJ/m

3

.

(4) Based on gross CV 45.5 MJ/kg and specic gravity 0.835.

(5) Hydraulic resistance (mbar) = (Flow rate (m

3

/h))

2

x z

Figures are based on the maximum boiler outputs.

Type 500 600 700 900 1200 1500

• Maximum output kW 500 600 750 1000 1250 1500

• Minimum output kW 225 300 375 500 625 750

• Boiler input at maximum output kW 546.45 656.50 818.77 1094.09 1366.12 1646.54

• Boiler input at minimum output kW 240.60 322.23 401.50 534.76 667.74 803.86

• Maximum boiler operating temperature

(1)

°C 100 100 100 100 100 100

• Minimum return temperature (oil/gas) °C 60/55 60/55 60/55 60/55 60/55 60/55

• Minimum ue gas temperature °C 140 140 140 140 140 140

• Maximum working pressure / test pressure bar 6/9 6/9 6/9 6/9 6/9 6/9

• Boiler efciency net

(2)

at 100%PN % 91.5 91.4 91.6 91.4 91.5 91.1

at 30%PN % 93.5 93.1 93.4 93.5 93.6 93.3

• Standing losses qB at 70°C Watt 1250 1500 1725 1800 2375 2400

• Insulation thickness mm 100 100 100 100 100 100

• Fuel Consumption at maximum output
Nat Gas

(3)

m3/hr 56.35 68.07 84.90 113.45 141.66 170.73

35 seconds oil

(4)

litres/hr 55.17 66.13 77.22 99.37 137.87 166.16

• Hydraulic resistance through the boiler

(5)

z-factor 0.020 0.020 0.010 0.011 0.011 0.009

• Hydraulic resistance with 11 K

T m bar 30.55 44.00 34.36 67.20 105.00 122.31

• Hydraulic resistance with 20 K

T m bar 9.25 13.31 10.39 20.33 31.77 37.43

• Water Flow rate with 11 K

T m3 / h 39.08 46.90 58.62 78.16 97.71 117.25

• Water Flow rate with 20 K

T m3 / h 21.50 25.80 32.24 42.99 53.74 64.49

• Boiler water content litres 800 770 1340 1250 1320 1330

• Dry Weight (without burner)

(6)

kg 1700 1754 2463 2616 3350 3650

Type 1750 2000 2250 2500 3000 3500 4000

• Maximum output kW 1760 2050 2350 2650 3000 3500 4150

• Minimum output kW 880 1025 1175 1325 1500 1750 2075

• Boiler input at maximum output kW 1931.94 2242.89 2573.93 2908.89 3285.87 3837.72 4555.43

• Boiler input at minimum output kW 945.22 1100.97 1260.73 1418.63 1602.56 1871.66 2226.40

• Maximum boiler operating temperature

(1)

°C 100 100 100 100 100 100 100

• Minimum return temperature (oil/gas) °C 60/55 60/55 60/55 60/55 60/55 60/55 60/55

• Minimum ue gas temperature °C 140 140 140 140 140 140 140

• Maximum working pressure / test pressure bar 6/9 6/9 6/9 6/9 6/9 6/9 6/9

• Boiler efciency net

(2)

at 100%PN % 91.1 91.4 91.3 91.1 91.3 91.2 91.1

at 30%PN % 93.1 93.1 93.2 93.4 93.6 93.5 93.2

• Standing losses qB at 70°C Watt 2475 2510 2530 2570 2960 3070 3160

• Insulation thickness mm 100 100 100 100 100 100 100

• Fuel Consumption at maximum output
Nat Gas

(3)

m3/hr 200.33 232.58 266.90 300.97 340.35 397.51 455.30

35 seconds oil

(4)

litres/hr 194.96 226.34 259.75 276.93 330.87 387.86 443.09

• Hydraulic resistance through the boiler

(5)

z-factor 0.008 0.006 0.006 0.0015 0.0015 0.0015 0.0017

• Hydraulic resistance with 11 K

T m bar 151.40 154.06 202.45 64.36 82.48 112.96 166.19

• Hydraulic resistance with 20 K

T m bar 45.80 46.60 61.24 19.47 24.95 33.96 50.27

• Water Flow rate with 11 K

T m3 / h 137.57 160.24 183.69 207.14 234.49 277.57 312.66

• Water Flow rate with 20 K

T m3 / h 75.66 88.13 101.03 113.92 128.97 150.47 171.96

• Boiler water content litres 2150 2690 3350 3660 3670 4020 4130

- Dry Weight (without burner)

(6)

kg 4325 4600 5400 5900 6525 8700 10850

SR-plus 1750 - 4000

(6) Dry weights based on the 6 bar boiler. To calculate the weight of an 8 bar

version add 30%.

SR-plus 500 - 1500

August 2014

7

SR-plus Technical & Performance Details

Dimensions and Technical Information

SR-plus heating boiler (models 500 to 900)

Key

1 Flow 4 Hydraulic Drain 7 Flue gas Test Point

2 Return 5 Flue Outlet 8

Smokebox Condensate
Drain Connection

3 Safety Valve Connection 6 Smokebox Cleaning Door 9 Control Panel

A single phase 230V supply is required for the
control panel operation. Single phase burners
are electrically supplied via the control
panel. Three phase burners require a
separate three phase isolated supply (by the installer

to allow for boiler/burner door opening. A separate

run between the control panel and the burner. All
power supplies to the boiler/burner/other associated
equipment (ie: gas booster, separate oil pump, etc.)
should be isolated via the same switched isolator.

2

L

D

F

J

H

G

C

M

E

3

8

4

9

9

Burner

CL

1

6

5

7

Elevation view

N

205

SR-

Plus

Model

kW
Rating
at high

A B C D E F G H J L M N

Flow/return

BS4504 PN16

Safety

valve

Flue I/D

Dry

Weight

kg

Water

Content

litres

500 411-500 1413 1262 2323 1958 766 190 1320 920 280 766 1486 1371 100 N/B R 2" 250 1700 800

600 501-600 1413 1262 2323 1958 766 190 1320 920 280 766 1486 1371 100 N/B R 2" 250 1754 770

700 601-750 1582 1440 2809 2414 856 220 1780 1330 365 856 1650 1535 125 N/B R 2" 300 2463 1340

900

876-

1000

1582 1440 2809 2414 856 220 1780 1330 365 856 1650 1535 125 N/B R 2" 300 2616 1250

L

F

A

Rear view

B

5

6

9

9

1

4

Burner

CL

8

2

7

7

205

Control panels are
mounted on top of the boiler as
standard up to SR-plus 900.
Side mounting (left or right)
can also be accommodated.

Note:

August 2014

8

SR-plus Technical & Performance Details

Dimensions and Technical Information

SR-plus heating boiler (models 1200 to 4000)

Key

1 Flow 4 Hydraulic Drain 7 Flue Gas Test Point

2 Return 5 Shell Access Connection 8 Flue Outlet

3 Safety Valve Connection 6 Smokebox Cleaning Door 9 Control Panel

10 Smokebox Condensate Drain Connection

A single phase 230V supply is required for the control
panel operation. Single phase burners are electrically
supplied via the control panel. Three phase burners
require a separate three phase isolated supply

connection to allow for boiler/burner door opening. A separate

the control panel and the burner. All power supplies to the boiler/
burner/other associated equipment (ie: gas booster, separate oil
pump, etc.) should be isolated via the same switched isolator.

SR-

Plus

Model

kW Rating

at high

A B C D E F G H J L M N

Flow/Return

BS4504 PN16

Safety valve

Flanged

to BS4504

PN16

(from model

1750)

Flue I/D

Dry

Weight

kg

Water

Content

litres

1200 1151-1250 1626 1500 2909 2514 876 220 1795 1345 380 876 1745 1630 125 N/B R2” 350 3350 1320

1500 1426-1500 1722 1590 2909 2514 927 220 1806 1356 466 927 1833 1718 150 N/B R2” 400 3650 1330

1750 1625-1760 1852 1720 3361 2966 992 220 2137 1687 500 992 1990 1875 150 N/B 100 N/B 400 4325 2150

2000 1900-2050 1952 1820 3381 2966 1042 240 2137 1687 590 1042 2090 1983 150 N/B 100 N/B 450 4600 2690

2250 2200-2350 2103 1970 3494 3069 1118 250 2200 1750 590 1118 2260 2145 150 N/B 100 N/B 450 5400 3350

2500 2450-2650 2143 2016 3585 3140 1135 270 2372 1922 600 1135 2323 2208 200 N/B 100 N/B 450 5900 3660

3000 2900-3000 2261 2120 3674 3219 1200 280 2502 2052 600 1200 2448 2333 200 N/B 100 N/B 500 6525 3670

3500 3250-3500 2477 2300 4235 3720 1327 340 2652 2112 812 1327 2628 2513 200 N/B 100 N/B 500 8700 4020

4000 3750-4150 2660 2400 4270 3759 1460 340 2662 2162 812 1460 2702 2587 200 N/B 100 N/B 550 10850 4130

Control panel can be
mounted on left or right
hand side.

2

L

D

F

J

H

G

C

M

E

3

8

4

9

9

Burner

CL

1

6

5

7

Elevation view

N

L

F

A

Rear view

B

5

6

9

9

9

1

4

Burner

CL

8

2

7

7

August 2014

9

Space requirements, boiler plant house noise levels

Space Requirements

Where ever possible space should be left around the boiler to enable all parts to be examined and
the cubicle casings to be tted or removed easily.

Clearances

a) Back clearance is required for the system water, ue connections and access to cleaning door.
b) Front clearance is required to swivel the boiler door ncluding burner by 90

o

, (standard to the
right optional to left) Space requirements to right when right hinged 80mm (plus burner length).
Clearance is equal to approximately the length of the boiler base (D) should be allowed for tube
cleaning and tube repairs. Shorter clearances are possible subject to cleaning methods and
plantroom layout.
c) When the boiler is gas red, allowance must be made for bringing the gas piping up to the
boiler front and to leaving space for the gas pipework at he side of the boiler or in the most suitable

direction

e) It is possible to install two boilers without intermediate space. (Important boiler door on left boiler
must be swivelled to the left and boiler door on the right boiler to the right).

Additional points

When pipework is being connected to the boiler, care must be taken not to damage the casings,
which are not designed to be stood on.
External weight or thrust from system pipework attached to the boiler should be avoided by careful
design of pipework runs and the use of expansion joints as required

.

Measures can be adopted to reduce noise levels if it
is considered that any of the following sources will be
objectionable:

1) Direct transmission through the building structure,
e.g. rooftop boilerhouses causing vibration and
sound to be transmitted to the space below.

2) Sound transmission through the boilerhouse fabric
e.g. dwellings very close to the boilerhouse may be
subject to objectionable noise from a building,
without sound insulation, through the walls and air
ventilation openings.

3) From the chimney outlet e.g. where dwellings are
located very close by the boilerhouse or above the
chimney outlet. Natural gas red plant has low
frequency sound pressure levels which are
disturbing to nearby residents when the boilers are
operating, particularly at night.

The following are sound and vibration control measures
which can be taken in respect of the points raised
above:

• Acoustic burner and booster shrouds

• Acoustic air intake bafe or acoustic louvres.

• Heavy construction or sound insulated external
walls, double glazing, heavy and close tting doors
to the boilerhouse.

• Heavy construction ue with insulated cavity all
round when the ue rises within the occupied areas
of the building. Double skin insulated ues for ues
installed outside the building.

• Flue noise attenuator.

• Anti-vibration mounts for the boiler case.

• Peripheral gaps around pipes to be sealed with
suitable acoustic material.

• Anti-vibration connections to pipework and pumps.

• Heavy construction of suspended oor or ceiling.

Boiler Plant Noise Levels

Changing the door hinged side

The boiler door is substantially hinged to carry the full burner weight but no extra weight should be imposed.

1. Open the door as hinged and screw on two spare locknuts on the door hinge bolts to locate
the door bosses on the new side.

2. Close the door. Adjust the locknuts temperorarily and replace one door nut tightly.

3. Change the other nut over with its plain diagonal counterpart from the other side of the door
and tighten both.

4. Adjust the locknuts so that a seal is obtained all round the bre joint.

5. Open the door and remove the original locknuts.

Important

• Always have two nuts tightened to prevent the door falling.

• It is essential that the door seal is in place correctly after closing the door every time.
Replace the joint if in doubt and check there are no fumes escaping.

This is a specialist subject and where noise due to vibration, combustion or mechanical sources is
likely to be a problem, Hoval should be advised.

August 2014

10

Boilerhouse Ventilation

Natural Ventilation - General Guidelines

The permanent ventilation of the boilerhouse
(not including doors and windows which may be
closed) is essential.
Boilerhouse ventilation serves two essential
purposes. One is to permit combustion air to ow
freely to the burners from outside the building and
the second is to maintain a clean atmosphere
within the boilerhouse at a reasonable temperature
level.
Heat released from the boiler, the piping and
the ues should not increase the boilerhouse
temperature above 30

o

C.

Air Inlet Requirements

It is essential that xed air openings are provided
at high and low level adjacent to the boiler front.
Free inlet area of louvres required for ventilation
and combustion air should not be less than
640mm

2

/kW rating (30in3 per therm) (1m2 per
1500kW boiler rating). The inlet opening should
be at low level with a further ventilation opening
of half that area at high level.

Air inlets and ventilation outlets are best disposed
at low level and high level respectively, so that
air convection across the boilers will create the
necessary air changes.

Boilerhouse ventilation should

conform with the relevant British
Standards, Codes of Practice etc.

Preferably the high level openings should not be
too close to the low level opening such that short
circuiting of air, without ventilation across the
boilers, can occur. Where louvres are utilised in
the boilerhouse door, louvres over the full door
height are satisfactory.
For boilerhouses below ground level, arrangements
should be made to induce fresh air into the
boilerhouse where a natural ow of air is restricted
by the buoyancy of air leaving higher level
openings.

Air Supply by Mechanical Ventilation - General
Guidelines

The supply of air to a space housing the boiler
by mechanical means should be mechanical inlet
with natural or mechanical extraction. Mechanical
extract ventilation with natural inlet must not be
used.

Any mechanical means of entering air into a
basement boilerhouse should have a balancing
outlet so that the air pressure in the boilerhouse
does not exceed 0.05" W.G. (12.5 Pa).

Where mechanical inlet and mechanical extract
system is applied, the design extraction rate
should not exceed one third of the design inlet
rate.

Note: All air inlet and extract fans should be tted
with automatic controls interlocked with the boiler
controls to give a safe shutdown or lockout in the

Open Vented / Pressurised Systems

Open Vented Systems

A primary make up water and expansion tank is
required for open vented systems. With low head
on calorifier primary system, Hoval Technical
Department should be consulted.

The cold feed pipe should be connected into the
return water piping on the boiler side of any valve.

An open vented connection is provided at the

boiler rear. The vent pipe should be installed with
a continuous rise to a position over the primary
feed tank.

A safety valve should be installed in a tee piece as
near to the boiler as possible with no intervening
valve. It should be sized to the relevant British
Standard.

Pressurised Systems

For independently pressurised systems the vent
connection must be tted with an automatic air vent,
a safety valve (sized to the relevant British Standard)
and a pressure switch. No intervening valve is
permissible between the safety valve and boiler.

The pressure switch should be interlocked with the
boilers control circuit to safely close the burner down
in the event of pressure loss.

The pressurisation unit control should also be
interlocked with the boiler(s) controls to safely close
the burner down in the event of malfunction.

Hoval recommend that a Level Probe Switch is tted
in the ow pipe rising from the boiler. It should be
drained down for proving its operation periodically. It
should be interlocked with the burner control system.

Ventilation, Open Vented & Pressurised Systems

August 2014

11

Flues & Chimneys

Flues and Chimneys

Guidance for sizing ues and chimneys is given in
CIBSE and HVCA guides and also HovalTechnical
Data Sheets. Flues should conform to the relevant
British Standards, Codes of Practice etc.

General Guidelines

• Individual chimneys and flues should be used
whenever possible for multi-boiler plants so that
combustion conditions are not disturbed by the
operation of other boilers. Consideration should be
given to the condition of one boiler at low fire with
regard to low temperature and condensation
problems.

• Specialist ues are available for difcult situations
such as a low level ue adjacent to a tall building.
In this case a vertical balanced ue can be helpful.
Refer to Hoval for further details.

Fan Dilution Systems - General Guidelines

In circumstances where the provision of a conventional or
natural draught ue is impracticable because of the location
of the boiler plant, a fan dilution system may be used.

Dilution fan capacity (m

3

s) = 9.7 x boiler rating (kW)

at normal 3600 x 0.8

temperature and

pressure (N.T.P)

To adjust for the normal diluted outlet temperature of 50

o

C,

multiply the N.T.P. gure by 1.1154.

The dilution air intake should be independent of the
boilerhouse combustion and ventilation air supply.

Velocities in the fan intake and exit ducts should not exceed

7.5l/s to avoid ductwork resonance noise.

Air ow switch to be interlocked with burner controls.

Local Authority approval of height of the diluted ue outlet
is generally required.

Attention is also drawn to the need to include the fan and its
proving switches as in the normal routine boiler maintenance
programme.

Chimney sizes and height will need to take
into account the following:

1) Clean Air Act.

2) Local Regulations.

3) Environmental Protection Act 1990.

4) Considerations to adjacent buildings.

5) Transmission of noise, particularly low

frequency sound pressure levels in
quiet periods of the day or night from

natural gas red plant if dwellings are
very close.

6) Flue gases discharged to the
atmosphere which contribute to health

dangers should be minimised by
maintaining the burner and boiler to
ensure correct combustion and high

efciency to reduce running time to a
minimum and to maintain low levels of

CO2 (Greenhouse effect); CO and NOx

(dangerous gases). Current
regulations for NOx limits (1993) are
maximum 260 mg/kWh (148ppm at 0%

O2). Burners supplied with Hoval

boilers fully meet this requirement.

• Adequate doors should be provided in flues and
chimneys for cleaning and inspection purposes.
Square tees must not be used for creating a drain
point at a flue change of direction as this creates
difculties in ring the burner.

• Flues should be supported independently to prevent
undue weight and forces due to expansion being
transmitted to the boiler outlet connection.

• Where high gas outlet velocities are required from
the chimney, a coned outlet can be used. The
additional loss of draught due to this should be taken
into account in the chimney design.

• Steps should be taken in designing to prevent or
minimise condensation forming by using double skin
and/or insulated ue systems ad suitably insulated
brick stack or double skin steel chimney. This helps
prevent condensation from gas red plants.

• Header cross sectional areas should take account of
the quantity of gas owing at each intersection. Allow
for condensation points in chimney and flue.
Condensation should be drained at the base of the
vertical run. Horizontal runs should drain away from
the boiler.

• Where ues from two or more boilers join the header
the gas streams should be flowing in the same
direction at the point of intersection with the header.

• If two ues must enter into one common stack they
they should be positioned to cause the least
disturbance to the other gas stream (i.e. not opposite
to each other).

• In deciding the ue run, the chimney height buoyancy

should provide a negative pressure condition at

the boiler ue outlet of 15 pascals.

• Flues should not be less in diameter than the boiler
outlet connection size.

• Use of short runs of ues and with the minimum of
large radius bends without horizontal runs before
entering the main chimney at a 45

o

are recommended

and will cause the least resistance.

IMPORTANT

A condensate drain point is provided in the

boiler ue outlet box and this should be piped
to drain via a drain trap to prevent ue gases
escaping. No isolating valve should be tted
in this pipework.

August 2014

12

Filling the system

Recommendation

It is recommended that each system

should be lled or relled with treated

water and specialist rms will be able to

advise in this respect

Water treatment

There is basic need to treat water contained
in all heating and indirect hot water systems,
particularly open vented systems.

One millimetre of lime reduces the heat conversion
from ame via metal to water by 10%.

In practice the deposition of these salts is liable
to cause noises from the boiler body or even
premature boiler failure. Corrosion and the
formation of black iron oxide sludge will ultimately
result in premature radiator failure.

Open vented systems are not completely sealed
off from the atmosphere as it is essential to
provide a tank open to atmosphere if proper
venting and expansion of system water is to be
achieved. The same tank is used to ll the water
and it is through the cold feed pipe that system
water expands into the tank when the boiler
passes heat into the system.

Conversely when the system cools, water
previously expanded is drawn back from the
tank into the system together with a quantity of
dissolved oxygen.

Even if leakage from the heating and hot water
systems is eliminated there will be evaporation
losses from the surface of the tank which,
depending on ambient temperature, may be high
enough to evaporate a large portion of the system
water capacity over a full heating session.

There will always be corrosion within a heating
hot water system to a greater or lesser degree
irrespective of water characteristics unless the
initial ll water from the mains is treated. Even
the water in closed systems will promote corrosion
unless treated.

For these reasons Hoval strongly recommend
that when necessary the system be thoroughly
cleaned, prior to the use of a stable inhibitor, which
does not require continual topping up to combat
the effects of hardness salts and corrosion.

Hoval advise contact directly with major specialists
on water treatment such as Grace & Dearborn or
Houseman..

Check the following:

• all connections are made and tightened

• instrument pockets are tted and water tight

• spare sockets are tted with plugs and are
water tight

• all valves in the heating circuit are open

• mixing or diverting valves are opened half
way,
then gradually ll with water until the altitude
gauge (if tted) indicates the correct head

and

the header tank is lled to appropriate level

• the installation is completely vented

• if a pressurisation unit is installed reference
should be made to the makers lling

instructions and applied

• installation debris and any deposits from the
system are not allowed into the boiler

• the boiler is ushed out through the drain
connection to ensure that the boiler is clean

inside

• a large strainer is tted to older systems to
remove deposits before the return enters the
boiler.

Important

The whole system must be thoroughly
ushed with water to wash out foreign

matter and impurities in accordance

with CIBSE/BSRIA guidelines.

Filling the System

August 2014

13

Fitting the Burner

Fitting the Burner

The burner is normally attached to the boiler and is
pre-wired. In the event that the burner is supplied
separately, then the following procedure should be
used. An adaptor plate suitable for the type of burner
being used is supplied tted to the boiler door.

Important

Check from the nameplate that the burner received

is the one indicated on the advice note and that the

electrical supply details and the fuel shown agree with
those available on site.

Most burners can be lifted manually, but care should
be taken not to damage components and help should
be sought for handling the larger burners.

Fitting the burner

• Fit the burner to the door using the gasket
and studs provided. If an acoustic shroud with
a backplate is being used, refer to the notes
below before tting the burner.

• When the burner is securely fixed, check that
the boiler door will open fully 90o.

• In the case of oil fired burner, the position of
the oil strainer at the end of the xed oil supply
pipe should allow the door to open fully when
the exible oil piping is connected.

Dual fuel burners - important note

For dual fuel burners, the installer should t solenoid
oil supply valves with micro switches to interlock with
the burner and similarly the gas supply valve should
have micro switches.

Check for shrouds with wheels that space has been
allowed to wheel the shroud away from the burner on
a at and level oor in front of the burner.

Fire Sensor for gas or oil burners

This should be located just in front of the boiler door
and above it so that the door can be opened without
hindrance. This applies whether an acoustic shroud
is tted or not.

For dual fuel burners which do not have a clutch
release system for the oil supply when operating on
gas, arrangements should be made to circulate the oil
through exible piping for at least 5 metres so that the
pump does not overheat.

Gas burner valve trains should be located within
300mm of the burner and supported independently of
the boiler at the opposite side to the door hinge so that
the door can open after 'breaking' a connecting joint.

Sealing of the burner draught tube

A small annular space is necessary around the burner
draught tube in the door refractory to enable the burner
to be withdrawn. Seal this gap with the ceramic strip
supplied.

Acoustic Shrouds

Acoustic shrouds are available to special order for the
burner and gas booster.

Check that the shroud instructions for tting and space
requirements are to hand and studied before tting.
These instructions are not in this manual.

Water ow & return temperatures

Consideration will already have been given to the system ow and return temperatures but please note:-

1) The ow temperature can be adjusted to the maximum operating temperature, as outlined in page 5.

2) The return temperatures should be controlled to be not less than 60oC for oil and 55oC for gas at all times
by the use of suitable bypass/diverting controls.

3) Differentials between the ow and return should not exceed 25K. Where a differential is to exceed 20K
advise Hoval as considerations are necessary and alternative solutions can be suggested.

Burner matching

The boiler will normally be supplied by Hoval complete with a burner which is CE marked and is CE approved
for ring with the boiler. Where it is required to t an alternative burner, to comply with CE Directives, the boiler
must only be used with a burner having CE marking in accordance with Directive 90/396/EEC and Standard
EN 676 (Gas) or EN 267 (Oil). The fuel suppy requirements will be stated on the burner data plate.

The burner CE approval must also be based on a test in a test tank having dimensions no larger than the rel­evant boiler combustion chamber dimensions.

Please consult Hoval Technical Department for further information, if required.

Always t the front casing before burner on

SR plus boilers up to and including the SR

plus 600.

August 2014

14

Control Details

The control box is located at the top front of the boiler and encloses the appropriate thermostats.
Check that it also contains the correct wiring diagram.

Control Details

• Burner control circuit switch:

Switching the boiler ON:

Setting the switch to the On position will allow the

boiler to be switched on/off by any external controls,

e.g. time switch. When external controls are in the

ON position, the boiler will switch on/off at the

dictates of the control thermostats.

In the case of a gas burner if the boiler has been

off for a long period,or the gas supply has been

disconnected, ensure gas is purged to the boiler,

and the main pilot gas cocks are turned on before

switching to the ON position.

• Limit thermostat:

The maxiumum setting of the limit thermostat is 110

o

C.

The limit thermostat should normally be set 10

o

C

above the control thermostat (access to the limit

thermostat adjustment is gained from inside the

control panel (isolate electrical supply before

removing control panel cover). Note: Once turned

down, the limit thermostat cannot be turned up to

a higher temperature). If the boiler temperature

exceeds this, the boiler will be switched off and the

high temperature cut out light will be illuminated (the

boiler will not operate until the limit thermostat is

manually reset).

•

High temperature cut out light

If the high temp cut out light is illuminated, the limit

thermostat will need to be manually reset. Allow

the boiler to cool down, then unscrew the protective

cover of the reset button. Press the button in and

replace the cover. The boiler will automatically

resume operation. If there are repeated faults,

contact the Hoval Service Department.

• Burner lockout light:

If the burner lockout light is illuminated, the

burner control will have gone to lockout. To rectify

this, press the illuminated button on the burner

control box. If the burner goes to lockout several

times in a short period, contact the Hoval Service

Department.

• Terminals

Terminals are provided in the control panel for linking

in additional controls e.g. time switch, pressurisation

unit, interlocks etc.

The control panel (as illustrated) is generally supplied for mounting on top of the boiler casing by the installer.
For normal high/low operation the control stat is set by the Hoval commissioning engineer at the required lev-

el e.g. 80oC . The limit stat will be set at a minimum of 6oC above this and the high/low stat at 3 to 5oC below
the operating stat setting (where tted). For other special requirements refer to the wiring diagram. A exible
lead is provided from the control panel which has to be wired into the burner terminals by the Installer prior to
commissioning. (See important note below)

• Control thermostat:

The control thermostat should normally be set in

the range 70-83

o

C. It can, however, be set higher,

up to 100

o

C maximum.

Access to the control thermostat adjustment is

gained by removing the circular disc on the front

of the control panel.

1 6 7 8

Key

1. Burner control circuit switch

2. Burner run light

3. High re run light

4. High temperature cutout light

5. Burner lockout light

6. Control thermostat adjustment

7. 2nd stage thermostat adjustment (where tted)

8. 3rd stage thermostat adjustment (where tted)

9. Limit thermostat manual reset

10. 3 Amp control circuit fuse

11. 6.3 Amp burner control circuit fuse

12. Space for optional burner hours run meter

13. Boiler ow temperature thermometer

14. Space for optional burner modulation controller

9 10 11 12 14

2
3
4
5

IMPORTANT -

A single phase 230V supply is required for the control panel operation. Single phase burners are
electrically supplied via the control panel. Three phase burners require a separate three phase

isolated supply (by the installer) direct to the burner, incorporating a exible connection to allow for
boiler/burner door opening. In this case control cables tted with wieland plug/sockets will still run
between the control panel and the burner. All power supplies to the boiler/burner/other associated
equipment (ie: gas booster, separate oil pump, etc.) should be isolated via the same switched isolator.

!

August 2014

15

Gas Boosters

Installation - Gas Boosters

A booster is required when the gas pressure at the burner is
below the value specied by the burner manufacturer at the ow
rate attained at maximum burner rating.

Gas Regulations require that no more than 0.5" WG pressure
is lost due to pipe work resistance between the supply meter
and the gas inlet.

Booster Installation

It is usually preferably to locate the boosters as near as
possible to the burner served rather than close to the meter.

• Leave adequate access for servicing drive belts, fan
bearing assemblies, electrical motors and any acoustic
shroud.

• Ensure that the room in which the gas booster is to be
installed is well ventilated and free from dust.

• Before running the booster the machine should be cleaned
thoroughly, taking particular care to make sure that pulleys
and the belt are free from abrasive dust etc, which may
have settled on the machine during installation.

• If the booster is in the boilerhouse then the ventilation and
air inlet louvres for the boiler will also serve for the booster
to keep the ambient temperature satisfactory, providing the
full recommendations for free area and position are fullled.

• Standard boosters are designed to operate in ambient
temperatures not exceeding 40

o

C. When the booster is
housed separately to the boiler, ventilation must be
provided to keep the ambient temperature below this.
Ventilation openings in this case must be sized relative to
any heat emiters in the room and the effects of solar gain.

• The booster control enables the booster to work
automatically. Gas ow through the booster is required to
stop any excessive increase in operating temperature
and we recommend that the booster should only operate
in conjunction with the burner. Prolonged periods of
operation without any gas ow will cause an increase in
temperature, shortening the life of the booster and
increasing service frequency. If however the plant is
required to work under such conditions, consideration
should be given to the use of a purpose-designed bypass
to dissipate the excess heat and the installation of a twin
duty stand-by system to allow for regular inspection. Where
a stand-by booster is tted, it should be operated regularly
or in rotation. If the booster is operating in rotation auto
cycling may have been installed as an option.

Important

If a vital function is served, install

a standby gas booster.

Do not test the fan chamber assembly by hydraulic

pressure: this practice will inevitably damage the fan
bearing assembly.

All booster assemblies are tested for gas tightness

by means of air at a pressure of 0.69 bar during
manufacture.

• Concrete oors should be sealed.

• Locate the booster on a rm, at horizontal plinth approximately
450mm high to raise the unit to a convenient level.

• Noise attenuation and absence resonance are best obtained by
supporting the booster on anti-vibration mounts.

• For the same reasons, connecting pipework needs to be
accurately aligned and properly supported. The use of exible
pipes between the inlet and outlet ports of the booster and
pipework is strongly recommended. These exible pipes will
reduce risk of resonance in the pipework system and eliminate
strain on the fan chamber.

• Changes in pipwork sizing are best made close to the booster
ports. The use of expanders and reducers are recommended to
minimise pressure losses.

• Where it is necessary to reduce or increase pipe sizes, the ttings
should be sized to minimise pressure losses by changing cross
section of pipework in easy stages.

• Connections for pressure testing or for pressure switches should
be located at points in the system where there is not excessive
turbulence i.e. where there is a straight run of pipework at both

sides of the switch (i.e. at least 10 diameters of straight pipe).

NOTE :­ If a gas booster is located in a meter/governor room then the
associated electrical equipment, i.e:- control panel, motor,
pressure switches should be suitable for use in a Zone 2 area

with group II A gases (refer to BS4683, part 3)

NOTE: Flexible piping should be examined by the operator

on a monthly basis. Change if there are any signs of
deterioration or cracking.

August 2014

16

Commissioning

It is essential that the following points are completed by the Heating

Engineer before commissioning is requested through Hoval.

• System full of water and vented

• Boiler ue box drain pipework is tted

• Spirals tted where appropriate

• Heating load available e.g. pumps working

• Fuel purged to burner isolation valve

• Oil bled to boiler isolation cock

• Electrical connections made and correctly fused

• Correct boilerhouse ventilation

• Other manufacturer's equipment has been installed
& commissioned as necessary, e.g. pressurisation units.

If the above are not completed and commissioning is unable to

commence, clients will be charged for the abortive visit.

Hoval Service Engineers normally commission all new
boilers and they will check the following:

• the boiler and system is lled with water and vented, including circulation pumps.

• the boiler ue box drain pipework is tted.

• an independently pressurised system is operating correctly. Suppliers of the equipment
should adjust their equipment during commissioning.

• that dampers in the flue between the boiler and the chimney (if fitted) are in
the open position and locked open if manually operated and if electrically operated that the
burner is interlocked electrically to prevent operation until the damper is open.

• the electrical installation with the appropriate wiring diagram for the boiler and burner and for
correct fan rotation.

• correct direction of ow in the gas line.

• correct operation of the gas booster (if tted)

• on oil burners that a lter and exible oil supply pipe-line is tted.

• the burner has not been damaged in transit or during installation and that it is a suitable type
for the fuel available on site. The nameplate on the burner indicates for which type of fuel it
is designed.

• excessive space in the refractory opening around the burner has been sealed with the supplied
ceramic material.

• all items, packed in transit, are removed from combustion chamber.

• boiler control thermostats are adjusted to suit system design ow temperature.

• the limit and high/low stats are set in accordance with control details. See page 14.

• the boiler relief valve setting is suitable for the system (The setting should be at least 0.5 bar
above the system pressure).

• oil supply pressure and temperature is suitable.

• for pressurised systems, an AAV is tted on each boiler.

Commissioning

August 2014

17

All settings both on boiler and

burner will be recorded on a

commissioning report which

will be supplied to the

customers representative.

Commissioning Report

Commissioning

• commissioning is in accordance with burner makers requirements.

• controls are proved and stats are adjusted in line with temperature indicated on the
boiler thermometer.

• that the boiler is red up at a rate allowing the door refractory to reach a uniform
temperature through its thickness thereby preventing any damage.

• burner is adjusted to give optimum combustion, together with flame shape and
penetration.

• the Heating Engineer will have the opportunity to receive instruction on the correct
operation of the plant during commissioning and to aquaint himself with the fault nding
chart on pages 23-26. He will also be advised on how much of the ‘action’ columns
can be dealt with by site staff.

August 2014

18

Operating Instructions

Operating Instructions

PLEASE READ: Important Notes for the
Boiler Attendant

Starting up after cleaning the boiler or

a Summer shut down.

Ensure that fuel lines are fully purged and that fuel
is available at the burner at the correct pressure and
temperature.

That spirals/retarders if supplied are retted

On a gas-red boiler, if the boiler has not been run for some time,
or if a fuel supply pipe has been disconnected, purge the piping
via the bleed nipple up stream of the burner to ensure that a
gas/air mixture is avoided.

On an oil-red boiler using class D oil in conjunction with a single­pipe supply system, ensure that air is bled from the system if the oil
pipe has been
disconnected.

Ensure fuel supply valves are open. Where a pump is incorporated in
an oil fuel supply system, ensure the pump is switched ON. Check all
switches, e.g. time switch, and thermostats are in the ‘calling’ for heat
condition. Switch ON electrical supply to the burner at the main switch.
Switch the control panel mounted switch to ON. The burner control
box should now monitor the burner through its prescribed sequence
to reach 'main ame on'.

Normal Running

The boiler will switch on/off under the dictates of the control thermostat. The
boiler temperature at any particular moment can be seen from the boiler
thermometer.

Allow the boiler to reach its set temperature and then check the
burner ame through boiler door sight orice; the ame should
extend well into the combustion chamber. Also check the ame
characteristics at the burner through the burner inspection
window. If any deterioration is noted, the heating engineer should
ensure the necessary action is taken.

These instructions are the minimum necessary to enable an
operator to start, run and stop the boiler.
They cover also the simple routine servicing procedures
necessary. Except where specically noted, they are applicable
irrespective of the fuel used - gas or oil - BS class D (35 sec).

If the heating system designer or installer has prepared operating
and maintenance instructions specically for the whole plant,
those instructions should be referred to in the rst instance.

Instruments and Controls

Instruments are generally mounted at the top front of the boiler.
A boiler ow water thermometer will always be present, an
altitude gauge may also be provided.

The basic controls for any boiler will be:-

a) A sequence-control box (mounted on the burner) which
automatically governs the ring sequence of pre-purge,
ignition, pilot or reduced start, and provides for safety
lock-out in the event of ame failure or other unsafe condition.

This control box will have advisible indication of lock out and a
manual-reset button for use in the event of ame failure.

b) A control thermostat which allows adjustment of the boiler
ow temperature is tted behind the instrument panel facia to
discourage unauthorised adjustment after it has been set by
the commissioning engineer.

c) A safety-limit thermostat which comes into operation should
the control thermostat fail to shut the burner down.The limit
stat is usually set at 10

o

C above the control thermostat’s
maximum setting. No automatic control may be interfered with
by the boiler attendant but must be adjusted only by a qualied
Service Engineer.

There may be special burner controls equipment or

additional controls to be integrated with the standard
burner control equipment. The function and setting of
these will be covered by the suppliers e.g. BMS.,
sequence controls high and low pressure switches and
water level controls, associated with independendently
pressurised systems.

NOTE: A gas/air mixture is dangerous as it
will explode if subjected to a spark.

Sequencing of boilers under BMS control.

When a bank of boilers are sequenced to operate under the dictates of a BMS control system, it is very

important that on-line boilers are "properly" matched to the available heating load at any one time.
This will avoid too frequent cycling of the burners as they stop and start (introducing cold pre & post purge
air into the boiler each time this happens).

Over time this can result in the boilers suffering from thermal shock and premature failure of the pressure

parts.

August 2014

19

A qualied boiler/burner service engineer will be required to carry out work other than the follow­ing: boiler cleaning, inspection of components for damage,
starting up the boiler, and the specified testing and minor

fault rectication.

Inspection & Servicing

Maintenance - Inspection & Servicing

No special equipment is required for normal boiler servicing.

Tools for cleaning the boiler heating surfaces are provided with
the boiler. If a hard scale forms from oil red corrosive elements,
a proprietary cleaning medium (e.g. Carbonex by Arrow Chemicals

Ltd) is advantageous for softening and easier removal of such

deposits.

The service engineers' equipment will include any necessary
special tools and also a combustion efciency test kit.

Periodic Inspection

The following periodic inspections should be made
between main servicing periods.

• Examine boiler casing panels for obvious signs of
damage, corrosion or other deterioration, and for
security. (Badly fitting casings and damaged
insulation materials leads to wasted heat and an
increase in the boilerhouse ambient temperature).

• Examine the flue pipe and gasket for obvious
signs of damage, corrosion, flue-gas leakage,
and for security. Similarly inspect the cleaning
explosion door at rear of boiler.

• Examine the ue and chimney, as far as possible,
for partial blockage, debris, etc.

• Ensure that condensation drains at the chimney
base are clear and that the boiler flue box
drain socket is connected to a drain pipe with a
water trap.

• Keep the boilerhouse floor clear of dust and
debris which may be drawn into the burner and
cause damage.

• Examine all fuel and water valves, connection
and burner etc, for obvious signs of damage or
leakage, and for security.

In an open-vented heating system, check:

- Level of water in the feed and expansion tank.

- That the ball valve is free to operate correctly.

- All air vents are operating correctly.

NOTE: No continuous make-up of water
should be taking place. (In this
event check where a leak may

be occurring or if pumping over

is taking place).

• On the boiler door, examine the ceramic-strip
seal, and check that there are no ue gas leaks.
Leaks can be detected by heat marks or deterio­ ration of the metal ring holding the joint. In the
event of such signs, replace the joint immedi­ ately. Check the filler material around the
burner tube and the door lining for deterioration.
Replace when required.

• Initially examine boiler interior after one month
when using class D oil to determine necessity for
boiler cleaning. When heavy oil is being used,
examine after two weeks. The amount of use, the
number of cold starts involved, and the mean
operating temperatures all affect the rate of soot
and scale formation.

A consistent pattern will then be established to
determine the frequency of cleaning required.
With gas much longer periods between cleaning
are usually possible. If condensation occurs due
to low return water temperatures then a build up
can occur more quickly. Establish a pattern to
see if cleaning can coincide with service visits.

After a boiler is rst commissioned, examinations
should initially be more frequent until a reason­ able, consistent pattern can be established.

• On oil/gas burners periodically remove photo
electric ultraviolet cell and clean the window of
the cell.

• Check that the flame shape and penetration
remain as at the initial commissioning. Report
any unusual alterations in this respect.

Report any occurrences which indicate that the
boiler, the ring equipment or the system controls
are not operating correctly.

August 2014

20

Boiler & Burner Servicing

In addition to the periodic inspections given on page 19 it is recommended that a complete check is carried
out on all components at appropriate intervals.

These checks must be made by a qualied boiler/burner service engineer, ideally under an annual sevice and
maintenance contract.

Hoval Service Department normally provides this service and will be pleased to provide a written quotation on
request. This would typically cover the operation, cleanliness, combustion efciency etc., of the fuel burner
and associated controls. In the case of gas burners it would include a check on the gas tightness of the gas
control valves at the burner if a gas leak detection unit is not tted. In addition if a gas booster is tted it
could also be covered in this service.

Please note No adjustment of internal components is permissible on either gas
or oil burners except by a qualied service/burner engineer.

If exible pipes are used for connecting the gas burner make a monthly leak test on these pipes.

Maintenance - Boiler & Burner Servicing

Boiler Cleaning for Heating Surface

Frequency of cleaning will be dependent on usage in conjunction with the condition of the boiler at the periodic
inspections, but the minimum requirements when using the various fuels are:-

1) Run the boiler until the burner automatically switches
off under action of the control thermostat. (It is
easier to clean a warm boiler).

2) Switch OFF electrical supply to the burner. Where
a plug connection is tted in the cable from the boiler
to the burner, disconnect at this point. Switch OFF
electrical supply to the booster.

3) Turn OFF all fuel shut-off valves at the burner.

4) Where rigid fuel pipes to burner are employed,
e.g. gas burners, disconnect pipe(s) to allow the
boiler door to open.

5) Fully open the boiler door complete with burner.

6) Clean the tubes using the supplied brush. Similarly
clean the combustion chamber when required. Avoid
damage to the ceramic sealing strip against which
the door closes.
NB remove spirals if tted.

7) Remove rear cleaning/explosion door. Clear loose
soot from the smoke outlet box and thoroughly clean
the box. Clean and examine the boiler backplate;
no hard deposit should be present. Remove any
build up occuring between the projecting tube ends.

8) Ret spirals if originally tted.

(9) Check conditions of cleaning/explosion door gasket.
Ret door, ensuring it seats correctly on the gasket
tighten the wing nuts only two full turns against
spring compression.

Gas (natural or LPG) - once per heating seaon
Oil BS Class D (35 sec) - twice per heating season

Oil heavy grades - 3 to 4 times per heating season

NOTE: Lengthy periods between cleaning
should only be resorted to when the
periodic inspections prove this is possible.

NOTE: Where any hard scaling is present,
use a propietary cleaning medium

to soften and assist removal.

NOTE: Where heavy oil is being used
on a circulatory fuel system,
ensure that fuel pump(s) heaters
and tracers are left in operation at

all times.

August 2014

21

9) Check condition of boiler door ceramic seal.
Inspect the lining material on the door and lle
material around burner tube. Minor damage to
insulating material can be carefully rectied using
a mouldable refractory (e.g. Pyruma) on
refractory lined doors. Where a door is lined
with ceramic bre is unlikely to suffer damage
in normal use but in the unlikely event please
consult Hoval. Any serious damage must be
reported to the Service Engineer for repair. Filler
material can be repaired similarly. The door
sealing strip must be in good condition and must
be replaced when an effective seal cannot be
obtained under normal pressure. Replace
sealing strip annually. Refer to Burner
Maintenance Instructions Page 22 whilst the door
is open.

10) Close the boiler door, and evenly tighten the
nuts using a tommy bar/spanner.

Maintenance - Summer shut down

11) If disconnected, plug in the boiler/burner electrical
connection.

12) Check boiler door is effectively closed (ineffective
closure will be detectable by sight or smell).

13) It is recommended that, when the boiler has
become thoroughly hot, a combustion efciency
check is made by the Service Engineer.

14) If the boiler is not immediately to be used, switch
OFF electrical supply to burner and turn OFF fuel
supply. Where using heavy oil do not switch off
fuel heaters and tracers. Switch off electrical supply
to gas booster.

Summer Shut Down

If the boiler is to be out of operation for a long period, e.g. during the Summer, the boiler
interior should be thoroughly cleaned.

Atmospheric condensation, activating acidic deposits in the boiler, is responsible for

considerable corrosion and metal wastage. Every effort should be made to reduce this by
the most thorough cleaning and by keeping the boiler dry.

A tray of absorbing material placed in the combustion chamber is helpful in this respect.
Close the boiler door.

August 2014

22

Maintenance - Burners

Burner Maintenance

Impor-

Before carrying out any work on the burner ensure that the main electrical isolating switch is
in the OFF position and the fuel isolating valve closed.

These instructions are provided for the benet of the
operator and are intended to be of assistance in making
minor adjustments and proving the burner with proper
maintenance, cleaning and lubrication. Additional
information can be obtained through your installer or
from the manufacturer.

• Fuel

The unit is designed to burn the fuel stated on
the burner nameplate. Under no circumstances
must any other type of oil or gas be used.

In the case of burner fuel conversion, check to see
that the fuel used corresponds with that marked on
the new burner nameplate.

• Starting and Stopping

• Emergency Stop

The burner can be stopped in an emergency by
switching off the mains isolating switch provided on
the line between the burner and the electric supply.
The installer must identify the switch. Check position
of this switch or any "panic button" available.

• Check the Burner Operation

Inspect burner ame periodically. If it becomes lop
sided or there is any noticeable change in ame
colour, call the service engineer.

When cleaning the room housing the heater unit,
always switch off the burner to reduce the amount
of dust and lint drawn in through the air inlet.

• Preventive Maintenance

Consult your heating engineer for advice on regular
prevetive maintenance intervals.

• Gas Supply

Should the gas supply be interrupted, the system
may require venting of air that may have
accumulated, before the burner is restarted. This
is achieved by unscrewing the pressure test point
situated down-stream of the main govenor or
combination valve and venting the air to atmosphere
until gas has reached the test point.

WARNING: No smoking or naked lights to be

allowed as a gas/air mixture is
dangerous.

Periodical examination of all pipework should
be carried out. The recommended method is
to brush a soap solution around all the jointed
areas. A leak in the system would have the
effect of forming bubbles.

CAUTION: Do not place any items in the boiler
combustion chamber as it is not
suitable for burning waste.

• Oil pump

See burner manufacturers manual.

• Gas train items and gas leak detectors

For maintenance of these units refer to the
manufacturers manual.

• Motor

Keep the burner motor clean and dry. Any deposits
of dust or lint should be blown out occasionally. On
motors provided with oiling holes, a few drops of
high quality SAE 20 oil should be injected every six
months. Surplus lubricant spreading from the
bearings should be wiped away. Some motors have
sealed-for-life bearings; these require no
maintenance.

• Fan Runner

Keep the fan blades clean and free from oil and
build up of dust or deposits picked up from a dusty
boilerhouse.

• Oil Strainer/Filter

Replace lter element anually.

• Nozzles, Flame Plate and Electrodes

Maintenance by the boiler operator is usually limited
to checking the condition of these items only whilst
the boiler door is open. Servicing the oil or gas
nozzle, which may require dismantling, and
replacement of parts should be left to the service
engineer.

The boiler operator may wipe off deposits of soot
and oil from the ame plate and nozzle taking care
not to disturb the parts. Check the electrodes are
set correctly after referring to the burner
manufacturers manual.

• Flame Sensor

Remove and clean the ame sensor which is an
ultraviolet cell for gas or photo-electric cell for oil
with methylated spirit on a lint free cloth. Do not
handle window of the ame sensor after cleaning.

NOTE: Remove the flame sensor before
attempting to remove the burner inner
assembly.

August 2014

23

NOTE: Rectication of any internal burner component must be done by a qualied burner

engineer.

Symptom

A. Burner will not start

B. Burner starts i.e. burner
motor runs but will not

light and burner goes to

'lockout'.

C. Burner lights but rapidly
extinguishes.

Possible Cause Action

1. Electrical supply failure

2. Control thermostat time or
water pressure switches or

other boiler systems controls
at fault

3. Manual reset on limit thermostat
tripped (when tted)

4. When using heavy oil tem-

pertures incorrect in oil pip-

ing or in burner preheater.

1. Check the following:
a) Main isolating switch of the
burner is on.

b) Overload protective device

of the burner motor.

2. Check that power is available

at the control panel and all

switches are closed.

3. Reset and check also control
stat setting and operation.

4. Check temperatures: ensure

preheating equipment is

operating.

1. Switch off burner. Check spark
plug gap. Check H.T. leads and
connections. Check and clean

ignition electrode(s) and insula­ tor

2. Open door and check whether

oil has been sprayed into
combustion chamber; if no
evidence of spray, clean or

replace burner nozzle(s).

3. Check as above. If no spray,
check the following:
a) There is oil in the fuel tank.

b) All necessary valves are

open.
c) The oil lter is clear.

d) There is no airlock in the fuel
pump (listen for any unusual

sound from pump).

e) For air leakage into the fuel

feed pump.
f) The re valve or re link has
not closed in oil line.

1. Remove cell, clean and ret.

2. Replace cell with new.

1. No ignition spark.

2. No oil spray into combustion
chamber but pressure indicated
on burner gauge (if fitted).

3. No oil spray into combustion
chamber and no pressure
indicated on the oil gauge.

1. Dirty photocell (causing 'lockout'
action).

2. Faulty photocell (causing 'lock­ out' action).

Oil Burner Fault Finding Chart

Oil Burner Fault Finding Chart

August 2014

24

Symptom

D. Smoky flame and/or
fumes from burner.
Flame shape alters from
normal. Boiler door
becomes hotter than
usual.

Possible Cause

1. Air inlet damper accidently

masked or other obstruction to

airow.

2. Alteration to air inlet damper
position.

3. Burner nozzle(s) dirty or badly
tted.

4. Incorrect nozzle(s).

5. Excessive oil pressure.

6. Boiler tubes, ue or chimney
blocked or re stricted. Flue
damper closed.

7. Burner draught tube or ame
plate misplaced or faulty.

8. Door refractory failure.

Action

1. Clear obstruction.

2. Reset damper and make a

combustion check (special

instruments required).

3. Replace nozzle(s).

4. Replace with correct nozzle(s).

5. Reset pump pressure regulator.

6. Clean tubes. Open ue damper
and check why it became closed.
Clear blockage or restriction.

7. Call Service Engineer to correct
and replace if necessary.

8. Check for damage, replace if
damage severe.

Oil Burner Fault Finding Chart

Oil Burner Fault Finding Chart / 2

August 2014

25

NOTE: Rectication of any internal burner component must be done by a qualied burner engineer.

Symptom

A. Burner will not start

B. Burner starts i.e. burner
motor runs but will not
light and burner control
box goes to 'lockout'.

C. Burner motor starts but
stops and re-cycles.

D. Burner shuts down
during operation and
recycles.

E. Burner shuts down
during operation and
goes to 'lockout'.

Possible Cause

1. Electrical supply failure.

2. Air pressure switch on burner not
operating.

3. Control thermostat, time, water
pressure switches or other boiler
system controls at fault.

1. No ignition spark.

2. Gas starvation.

3. Ultra-violet cell fault.

1. Air pressure switch on the burner.

As C1 above.

1. Flame failure

2. Ultra-violet cell fault.

Action

1. Check:
a) Main isolator switch is on and
power is available at the
control panel.

b) Overload protective devices

of burner motors (if tted).

2. Switch contacts must be in the
burner start position. Check
switch is not stuck in the satised
position.

3. Check:
a) That all switches are closed

b) Booster is not locked out due

to low inlet gas pressure and
that pressure switches
function correctly.

4. Reset and check. Also check

control thermostat setting and

operation.

1. See action B1. (Page 27)

2. Purge gas pipe, check pilot valve
operation.

3. Remove, clean and check

connections and replace if

necessary.

1. Check:

a) burner damper is open to

usual extent.
b) air inlet to switch is not
blocked.
c) switch is not stuck.
d) electrical connection.

As C1 above.

1. Check gas supply and pressure.

2. As B3 above.

Gas Burner Fault Finding Chart

Gas Burner Fault Finding Chart

August 2014

26

Symptoms

F. Burner lights on pilot but
burner locks out after 3 ­ 4 seconds.

G. Smell of gas local to the
appliance.

H. Combustion noise

  becomes louder, ame

becomes yellow. Boiler
door becomes hotter
than usual.

Possible Cause

1. Ultra-violet cell faulty

2. Ultra-violet cell is not receiving a
sufcient signal from the
ame

1. Leakage from pipe line joints or

pilot or that the main gas valves

are not gas tight.

1. Air inlet accidentally masked.

2. Air inlet damper position
moved.

3. Burner head parts have moved,
become worn or overheated.

4. Gas pressure alteration.

5. Boiler tubes, ue or chimney
blocked or restricted.

6. Door refractory failed.

Action

1. As B3

2. Clean cell and check correctly
inserted facing the ame

1. Switch OFF burner and check
pipe line joints with soap solution.

2. Close pilot manual valve and then

main manual valve at the burner

to see if this isolates the problem.

Call gas engineer to check the

automatic valves. Do not operate
until this has been done.

1. Clear obstruction.

2. Call Service Engineer to reset
and make a combustion check.

3. Call Service Engineer to adjust or

replace and make combustion

check.

4. Check and nd cause.

5. Check and clear restriction.

6. Replace if damage is severe.

Gas Burner Fault Finding Chart / 2

Gas Burner Fault Finding Chart

August 2014

Conservation of Energy

Protection of the Environment

Hoval Limited, Northgate, Newark, Notts NG24 1JN

Telephone: [phone] Fax: [phone]

e-mail: [e-mail]

Web Site: www.hoval.co.uk

March 2014