Building Regulations and the Benchmark Commissioning
Checklist
Building Regulations (England & Wales) require notification of
the installation of a heating appliance to the relevant Local
Authority Building Control Department. From 1 April 2005 this
can be achieved via a Competent Persons Self Certification
Scheme as an option to notifying the Local Authority directly.
Similar arrangements will follow for Scotland and will apply in
Northern Ireland from 1 January 2006.
The Health & Safety Executive operates the ‘Gas Safe Register’,
a self-certification scheme for gas heating appliances.
These arrangements represent a change from the situation
whereby compliance with Building Regulations was accepted as
being demonstrated by completion of the Benchmark Logbook
(which was then left on site with the customer).
With the introduction of Self Certification Schemes, the
Benchmark Logbook is being withdrawn. However, a similar
document in the form of a commissioning checklist and service
interval record is incorporated at the back of these instructions.
The Benchmark Scheme
Benchmark places responsibilities on both manufacturers and installers. The
purpose is to ensure that customers are provided with the correct equipment for
their needs, that it is installed, commissioned and serviced in accordance with the
manufacturer’s instructions by competent persons and that it meets the
requirements of the appropriate Building Regulations. The Benchmark Checklist
can be used to demonstrate compliance with Building Regulations and should be
provided to the customer for future reference.
Installers are required to carry out installation, commissioning and servicing work
in accordance with the Benchmark Code of Practice which is available from the
Heating and Hotwater Industry Council who manage and promote the Scheme.
Visit www.centralheating.co.uk for more information.
Applications for the copyright owner’s permission to reproduce or make other
use of any part of this publication should be made, giving details of the proposed
use, to the following address:
The Company Secretary, Baxi Heating UK Limited,
Brooks House, Coventry Road, Warwick. CV34 4LL
Full acknowledgement of author and source must be given.
WARNING: Any person who does any unauthorised act in relation to a
copyright work may be liable to criminal prosecution and civil claims for damages.
This company is a member of the Benchmark initiative and fully
supports the aims of the programme. Its aim is to improve the
standards of installation and commissioning of central heating
systems in the UK and to encourage the regular servicing of all
central heating systems to ensure safety and efficiency.
Building Regulations require that installations should comply
with manufacturer's instructions. It is therefore important that
the commissioning checklist is completed by the installer. The
relevant section of Building Regulations only relates to
dwellings. Therefore the checklist only applies if the appliance is
being installed in a dwelling or some related structure.
The flowchart opposite gives guidance for installers on the
process necessary to ensure compliance with Building
Regulations.
IMPORTANT - Installation, Commissioning, Service & Repair
This appliance must be installed in accordance with the manufacturer’s instructions and
the regulations in force. Read the instructions fully before installing or using the
appliance.
In GB, this must be carried out by a competent person as stated in the Gas Safety
(Installation & Use) Regulations.
Definition of competence: A person who works for a Gas Safe registered company
and holding current certificates in the relevant ACS modules, is deemed competent.
In IE, this must be carried out by a competent person as stated in I.S. 813 “Domestic
Gas Installations”.
The addition of anything that may interfere with the normal operation of the appliance
without express written permission from the manufacturer or his agent could invalidate
the appliance warranty. In GB this could also infringe the Gas Safety (Installation and
Use) Regulations.
Warning - Check the information on the data plate is compatible with local supply
conditions.
Legislation
This company declare that no substances harmful to health
are contained in the appliance or used during appliance
manufacture.
The appliance is suitable only for installation in GB and IE and
should be installed in accordance with the rules in force, and
only used in a suitably ventilated location.
In GB, the installation must be carried out by a Gas Safe
Registered Installer. It must be carried out in accordance with
the relevant requirements of the:
• Gas Safety (Installation & Use) Regulations.
• The appropriate Building Regulations either The Building
Regulations, The Building Regulations (Scotland), Building
Regulations (Northern Ireland).
• The Water Fittings Regulations or Water Byelaws in
Scotland.
• The Current I.E.E. Wiring Regulations.
Where no specific instructions are given, reference should be
made to the relevant British Standard Code of Practice.
In IE, the installation must be carried out by a competent
Person and installed in accordance with the current edition of
I.S. 813 ‘Domestic Gas Installations’, the current Building
Regulations and reference should be made to the current ETCI
rules for electrical installation.
All Gas Safe registered engineers carry an ID card with their licence number and a
photograph. You can check your engineer is registered by telephoning
0800 408 5500 or online at www.gassaferegister.co.uk
The boiler meets the requirements of Statutory Instrument “ The Boiler (Efficiency)
o
Regulations 1993 N
3083” and is deemed to meet the requirements of Directive
92/42/EEC on the energy efficiency requirements for new hot water boilers fired with
liquid or gaseous fuels:-
Type test for purpose of Regulation 5 certified by:
Notified Body 0085.
Product/Production certified by:
Notified Body 0086.
For GB/IE only.
All systems must be thoroughly flushed and treated with
inhibitor (see section 6.2).
Codes of Practice - refer to the most recent version
In GB the following Codes of Practice apply:
StandardScope
BS 6891Gas Installation.
BS 5546Installation of hot water supplies for domestic
purposes.
BS EN 12828Heating systems in buildings.
BS EN 12831Heating systems in buildings - Calculation of load.
BS EN 14336Installation & commissioning of water based
heating systems.
BS 6798Installation of gas fired hot water boilers.
BS 5440 Part 1Flues.
BS 5440 Part 2Ventilation.
BS 7074Expansion vessels and ancillary equipment for
sealed water systems.
BS 7593Treatment of water in domestic hot water
central heating systems.
In IE the following Codes of Practice apply:
StandardScope
I.S. 813Domestic Gas Installations.
The following standards give valuable additional information;
BS 5546Installation of hot water supplies for domestic
purposes.
BS EN 12828Heating systems in buildings.
BS EN 12831Heating systems in buildings - Calculation of load.
BS EN 14336Installation & commissioning of water based
heating systems.
BS 7074Expansion vessels and ancillary equipment for
sealed water systems.
BS 7593Treatment of water in domestic hot water
The following advice should be adhered to, from when first handling the boiler to the final stages of installation, and also during maintenance.
Most injuries as a result of inappropriate handling and lifting are to the back, but all other parts of the body are vulnerable, particularly shoulders, arms and hands.
Health & Safety is the responsibility of EVERYONE.
There is no ‘safe’ limit for one man - each person has different capabilities. The boiler should be handled and lifted by TWO PEOPLE.
Do not handle or lift unless you feel physically able.
Wear appropriate Personal Protection Equipment e.g. protective gloves, safety footwear etc.
Preparation
Co-ordinate movements - know where, and when, you are both going.
Minimise the number of times needed to move the boiler - plan ahead.
Always ensure when handling or lifting the route is clear and unobstructed. If possible avoid steps, wet or slippery surfaces, unlit areas etc. and take special care
on ladders/into lofts.
Technique
When handling or lifting always use safe techniques - keep your back straight, bend your knees. Don’t twist - move your feet, avoid bending forwards and
sideways and keep the load as close to your body as possible.
Where possible transport the boiler using a sack truck or other suitable trolley.
Always grip the boiler firmly, and before lifting feel where the weight is concentrated to establish the centre of gravity, repositioning yourself as necessary. See the
‘Installation’ section of these instructions for recommended lift points.
Remember
The circumstances of each installation are different. Always asses the risks associated with handling and lifting according to the individual conditions.
If at any time when installing the boiler you feel that you may have injured yourself STOP !!
DO NOT ‘work through’ the pain - you may cause further injury.
IF IN ANY DOUBT DO NOT HANDLE OR LIFT THE BOILER - OBTAIN ADVICE OR ASSISTANCE BEFORE PROCEEDING !!
1. The Potterton Heatmax Combi HE is a fully automatic gas
fired wall mounted condensing combination boiler. It is room
sealed and fan assisted, and will serve central heating and
mains fed domestic hot water.
2. The boiler is set to give a maximum output of :-
24 models - 24 kW DHW
21 kW CH (Condensing)
28 models - 28 kW DHW
25.9 kW CH (Condensing)
33 models - 33 kW DHW
30.3 kW CH (Condensing)
3. It is designed for use on Natural Gas (G20).
4. The boiler is suitable for use only on fully pumped sealed
heating systems. Priority is given to domestic hot water.
5. The boiler data badge gives details of the model, serial
number and Gas Council number and is situated on the inner
door panel or the control box. It is visible when the case front
panel is removed (Fig. 1).
Control Box
Facia Door
Fig. 1
Data Badge
Information Label
6. The boiler model name and serial number are also shown
on the information label on the back of the facia door. This is
for user reference.
7. The boiler is intended to be installed in residential /
commercial / light industrial E.M.C. environments on a
governed meter supply only.
8. The boiler must be installed with one of the purpose
designed flues such as the standard horizontal flue kit, part no.
5118489 .
9. All systems must be thoroughly flushed and treated with
inhibitor (see section 6.2).
IMPORTANT: If the boiler is installed at a high point in the
system it is strongly recommended that Automatic Air
Vent Kit 720004701 is fitted.
1.2Optional Extras
Integral timers, RF room thermostats, wall ‘stand off’ kits etc.
are available as optional extras.
1Primary Heat Exchanger
2Burner
3Ignition Electrodes
4Flame Sensing Electrode
5Gas Valve
6Pump
7Automatic Air Vent
8Plate Heat Exchanger/Automatic By-pass
9Flow Sensor with Filter & Regulator
10 Pressure Relief Valve
11 Boiler Drain Point
12 Heating Return
13 Cold Water Inlet On/Off Valve and Filter
14 Gas Inlet
Domestic Hot Water Circuit
24
22
21
1
2
4
3
20
23
5 6
8
9
10
1213141516
15 Domestic Hot Water Outlet
16 Heating Flow
17 Pressure Gauge
18 Water Pressure Sensor
20 Fan
21 Diverter Valve Assembly
22 Diverter Valve Motor
23 Domestic Hot Water Flow Temperature Sensor
24 Safety Thermostat
25 Central Heating Temperature Sensor
26 Expansion Vessel
1
7
11
17
3.1Central Heating Mode (Fig. 2)
1. With a demand for heating, the pump circulates water
through the primary circuit.
2. Once main burner ignites the fan speed controls the gas
rate to maintain the heating temperature measured by the
temperature sensor.
3. When the flow temperature exceeds the setting
temperature, a 3 minute delay occurs before the burner
relights automatically (anti-cycling). The pump continues to
run during this period.
4. When the demand is satisfied the burner is extinguished
and the pump continues to run for a period of 3 minutes
(Pump Overrun).
3.2Domestic Hot Water Mode (Fig. 3)
1. Priority is given to the domestic hot water supply. A
demand at a tap or shower will override any central heating
requirement.
2. The flow of water will operate the Hall Effect Sensor
which requests the 3 way valve to change position. This will
allow the pump to circulate the primary water through the
DHW plate heat exchanger.
3. The burner will light automatically and the temperature of
the domestic hot water is controlled by the temperature
sensor.
4. When the domestic hot water demand ceases the burner
will extinguish and the diverter valve will remain in the
domestic hot water mode, unless there is a demand for
central heating.
IMPORTANT: When the selector switch is in the ‘0’
(Off) position the electrical supply to the boiler is isolated.
The boiler will not operate and the integral timer (if
fitted) will require resetting once the selector switch is set
to either Position ( ) or Position ( ).
1. The frost protection mode is integral to the appliance and
functions only with the selector switch (see Section 2.1) in
the domestic hot water and central heating position. If the
system temperature falls below 5° C then the boiler will fire
on its minimum setting until a flow temperature of 30° C is
reached. Further protection can be incorporated by using a
system frost thermostat.
8
3.4Pump Protection
1. With the selector switch (see Section 2.1) in either the
9
23
10
11
17
1213141516
central heating or central heating and domestic hot water
position, the pump will automatically operate for 1 minute in
every 24 hours to prevent sticking.
Gas Supply-22mm
Central Heating Flow-22mm
Central Heating Return-22mm
DHW Flow Rate
@ 30o CRise11.4313.315.7
DHW Flow Rate
@ 35o CRise9.811.513.5
Min Working
DHW Flow Rate222
IMPORTANT: Where Low Flow Taps or Fittings are
intended to be used in the DHW system connected it is
strongly recommended that the DHW flow rate DOES
NOT fall below 2.5l/min. This will ensure reliable
operation of the DHW function.
l/min l/minl/min
Cold Water Mains Inlet-15mm
DHW Flow-15mm
Pressure Relief Discharge-15mm
IMPORTANT: If the boiler is installed at a high point in
the system it is strongly recommended that Automatic
Air Vent Kit 720004701 is fitted.
1. The Potterton Heatmax Combi HE Condensing Combination
Boiler is a ‘Water Byelaws Scheme - Approved Product’.
To comply with the Water Byelaws your attention is drawn to
the following installation requirements and notes (IRN).
a) IRN 001 -See text of entry for installation
requirements and notes.
b) IRN 302 -Byelaw 14.
2. Reference to the WRc publications, ‘Water fittings and
materials directory’ and ‘Water supply byelaws guide’ give full
details of byelaws and the IRNs.
6.2Central Heating Circuit
1. The appliance is suitable for fully pumped SEALED SYSTEMS
ONLY.
Treatment of Water Circulating Systems
• All recirculatory water systems will be subject to corrosion
unless an appropriate water treatment is applied. This means
that the efficiency of the system will deteriorate as corrosion
sludge accumulates within the system, risking damage to
pump and valves, boiler noise and circulation problems.
• When fitting new systems flux will be evident within the
system, which can lead to damage of system components.
• All systems must be thoroughly drained and flushed out
using, for example, Sentinel X300 or X400 or Fernox F3.
They should be used following the flushing agent
manufacturer’s instructions.
• System additives - corrosion inhibitors and flushing
agents/descalers should comply to BS7593 requirements, e.g.
Sentinel X100 and Fernox MB-1 which should be used
following the inhibitor manufacturer’s instructions.
• Full instructions are supplied with the products, for further
information contact Sentinel (0800 389 4670) or Fernox
(0870 870 0362)
Failure to flush and add inhibitor to the system will
invalidate the appliance warranty.
• It is important to check the inhibitor concentration after
installation, system modification and at every service in
accordance with the manufacturer’s instructions. (Test kits are
available from inhibitor stockists.)
• For information or advice regarding any of the above
contact Technical Enquiries.
6.3Bypass
1. The boiler utilises the primary side of the DHW plate heat
exchanger as an automatic integral bypass.
1. The boiler is designed for use in a heating system that
incorporates external controls, i.e. a minimum of a timer
device.
2. Suitable timer kits are available as optional extras.
3. For optimum operating conditions and maximum economy
the fitting of a programmable room thermostat is
recommended.
6.0System Details
6.5System Filling and Pressurising
Fig. 4
Filling Loop
Connections
Stop
Valve
DHW
Mains
Inlet
Fig. 5
Double
Check
Valve
Temporary
Hose
Stop
Valve
CH
Return
1. A filling point connection on the central heating return
pipework must be provided to facilitate initial filling and
pressurising and also any subsequent water loss
replacement/refilling.
A filling loop & instructions are provided with the boiler.
2. The filling method adopted must be in accordance with all
relevant water supply regulations and use approved
equipment.
3. Your attention is drawn to:
for GB: Guidance G24.2 and recommendation R24.2 of the
Water Regulations Guide.
for IE: the current edition of I.S. 813 “Domestic Gas
Installations”.
4. The sealed primary circuits may be filled or replenished by
means of a temporary connection between the circuit and a
supply pipe, provided a ‘Listed’ double check valve or some
other no less effective backflow prevention device is
permanently connected at the inlet to the circuit and the
temporary connection is removed after use.
6.6Expansion Vessel (Central Heating only)
1. The appliance expansion vessel is pre-charged to 0.5 bar.
Therefore, the minimum cold fill pressure is 0.5 bar. The
vessel is suitable for correct operation for system capacities up
to 125 litres. For greater system capacities an additional
expansion vessel must be fitted. For GB refer to BS 7074 Pt 1.
For IE, the current edition of I.S. 813 “Domestic Gas
Installations”.
Safety Pressure
Relief Valve
Fig. 6
Discharge Pipe
6.7Safety Pressure Relief Valve (Fig. 6)
1. The safety pressure relief valve is set at 3 bar, therefore all
pipework, fittings, etc. should be suitable for pressures in
excess of 3 bar and temperature in excess of 100°C.
2. The pressure relief discharge pipe should be not less than
15mm dia, run continuously downward, and discharge outside
the building, preferably over a drain. It should be routed in
such a manner that no hazard occurs to occupants or causes
damage to wiring or electrical components. The end of the
pipe should terminate facing down and towards the wall.
3. The discharge must not be above a window, entrance or
other public access. Consideration must be given to the
possibility that boiling water/steam could discharge from the
pipe.
4. A remote relief valve kit is available to enable the boiler to
be installed in cellars or similar locations below outside
ground level (kit no. 5121379).
1. All DHW circuits, connections, fittings, etc. should be fully
in accordance with relevant standards and water supply
regulations.
2. Your attention is drawn to:
for GB: Guidance G17 to G24 and recommendation R17 to
R24 of the Water Regulations Guide.
for IE: the current edition of I.S. 813 “Domestic Gas
Installations”.
Fig. 7
Check
Valve*
Pressure Reducer
Valve*
Stop Tap
To Hot
Taps
* See 6.8 for instances when
these items may be required
3. The Water Regulations recommendations for England and
Wales prohibits backflow from appliances into the
wholesome water supply due to thermal expansion.
However this type of instantaneous combination boiler, with
less than 15 litres of stored capacity, does not require any
backflow prevention device as any thermal expansion is
accommodated within the appliance.
It is possible in certain circumstances that other cold water
demands (e.g. washing machines, flushing of W.C.s) may
affect the DHW function of the boiler. In these instances the
fitting of a backflow prevention device and expansion vessel
is recommended.
4. Also if there is an existing check valve, loose jumpered
stop cock, water meter or water treatment device already
fitted to the wholesome water supply connected to the
boiler domestic hot water (DHW) inlet supply then a
suitable expansion device may be required.
5. If the hot water expansion is not provided for, then high
pressures can develop which may result in damage to fittings
and devices on the system.
6. The boiler’s maximum working mains pressure is 8 bar,
therefore all pipework, connections, fittings, etc. should be
suitable for pressures in excess of 8 bar. A pressure reducing
valve must be fitted for pressures in excess of 8 bar. The
manufacturer of any outlet fittings, such as a shower valve,
may require a lower maximum pressure. The pressure
reduction must take account of all fittings connected to the
DHW system.
1. If a shower control is supplied from the appliance it
should be of the thermostatic or pressure balanced type.
Thermostatic type shower valves provide the best comfort
and guard against water at too high a temperature. Existing
controls may not be suitable - refer to the shower valve
manufacturer.
6.10Hard Water Areas
1. If the area of the installation is recognised as a HARD
WATER AREA then a suitable device should be fitted to
treat the mains water supply to the boiler. Contact your
Water Distribution Company for advice on suitable devices.
7.0Site Requirements
5mm Min
Fig. 8
450mm
5mm Min
200mm Min
(300mm Min if
using 80/125mm
flueing system)
780mm
150mm Min*
7.1Location
1. The boiler may be fitted to any suitable wall with the flue
passing through an outside wall or roof and discharging to
atmosphere in a position permitting satisfactory removal of
combustion products and providing an adequate air supply.
The boiler should be fitted within the building unless
otherwise protected by a suitable enclosure i.e. garage or
outhouse. (The boiler may be fitted inside a cupboard-see
Section 7.3).
2. If the boiler is sited in an unheated enclosure then it is
recommended to leave the ON/OFF Selector Switch in the
domestic hot water and central heating position to give frost
protection.
3. If the boiler is fitted in a room containing a bath or shower
reference must be made to the relevant requirements.
In GB this is the current I.E.E. Wiring Regulations and Building
Regulations.
In IE reference should be made to the current edition of I.S.
813 “Domestic Gas Installations” and the current ETCI rules.
4. If the boiler is to be fitted into a building of timber frame
construction then reference must be made to the current
edition of Institute of Gas Engineers Publication IGE/UP/7
(Gas Installations in Timber Framed Housing).
450mm Min
For Servicing
Purposes
At Least 1.5°
*This is the MINIMUM recommended dimension. Greater
clearance will aid installation and maintenance.
7.2Clearances (Figs. 8 & 9)
1. A flat vertical area is required for the installation of the
boiler.
2. These dimensions include the necessary clearances around
the boiler for case removal, spanner access and air
movement. Additional clearances may be required for the
passage of pipes around local obstructions such as joists
running parallel to the front face of the boiler.
1. Where the appliance is installed in a cupboard or
compartment, no air vents are required.
2. BS 5440: Part 2 refers to room sealed appliances
installed in compartments. The appliance will run sufficiently
cool without ventilation.
7.4Gas Supply
1. The gas installation should be in accordance with the
relevant standards. In GB this is BS 6891. In IE this is the
current edition of I.S. 813 “Domestic Gas Installations”.
2. The connection to the appliance is a 22mm copper tail
located at the rear of the gas service cock (Fig. 10).
3. Ensure that the pipework from the meter to the
appliance is of adequate size. Do not use pipes of a smaller
diameter than the boiler gas connection (22mm).
Fig. A
Zone 1
Zone 0
Zone 1
Zone 0
Window
Recess
Zone 2
Zone 2
Window
Recess
Zone 2
0.6 m
In GB Only
Window Recess
Zone 2
Zone 2
0.6 m
2.25 m
Ceiling
Outside Zones
7.5Electrical Supply
1. External wiring must be correctly earthed, polarised and
in accordance with relevant regulations/rules. In GB this is
the current I.E.E. Wiring Regulations. In IE reference should
be made to the current edition of ETCI rules.
2. The mains supply is 230V ~ 50Hzfused at 3A.
NOTE: The method of connection to the electricity
supply must facilitate complete electrical isolation of the
appliance.
Connection may be via a fused double-pole isolator
with a contact separation of at least 3mm in all poles
and servicing the boiler and system controls only.
7.6Bath & Shower Rooms
1. If the boiler is fitted in a room containing a bath or
shower and NOT FITTEDwith any optional integral timer
or thermostat, it can be fitted in zone 2, (Figs. A & B shows
zone dimensions for a bathtub. For other examples refer to
the Current I.E.E. Wiring Regulations) reference must be
made to the relevant requirements.
In GB this is the current I.E.E. Wiring Regulations and
Building Regulations.
In IE reference should be made to the current edition of I.S.
813 “Domestic Gas Installations” and the current ETCI
rules.
Examples are shown of the following methods of termination:i) to an internal soil & vent pipe
ii) via an internal discharge branch (e.g. sink waste) downstream of the trap
iii) to a drain or gully
iv) to a purpose made soakaway
v) pumped into an internal discharge branch (e.g. sink waste) downstream of the trap
vi) pumped into an external soil & vent pipe
vii) to a drain or gully with extended external run & trace heating
It is strongly recommended to discharge internally into the household
drainage system. If connecting to a rain water drain, that drain MUST
discharge into a foul drain.
21.5mm
50mm per metre of pipe run
2.5° Minimum fall
32mm
i) Termination to an internal soil and
Insulation
vent pipe
7.0Site Requirements
7.7Condensate Drain
FAILURE TO INSTALL THE CONDENSATE
DISCHARGE PIPEWORK CORRECTLY WILL AFFECT
THE RELIABLE OPERATION OF THE BOILER.
CAREFUL CONSIDERATION MUST BE GIVEN TO THE
POSSIBILITY OF THE PIPEWORK BEING SUBJECT TO
FREEZING CONDITIONS AND APPROPRIATE
MEASURES TAKEN TO PREVENT BLOCKAGE.
CORRECT INSTALLATION IN ACCORDANCE WITH
THIS SECTION WILL CONSIDERABLY MINIMISE THE
LIKELIHOOD OF BLOCKAGE AND SUBSEQUENT
BOILER LOCK-OUT.
A CONDENSATE DISCHARGE PUMP AND PIPE ‘TRACE
HEATING’ ARE AVAILABLE AS ACCESSORIES - see
paragraphs 7.7.12 to 7.715 for further details.
The condensate discharge pipe MUST NOT RISE at any
point along its length. There MUST be a fall of AT LEAST
2.5° (50mm per metre) along the entire run EXCEPT
when employing a suitable condensate pump in basement
and cellar or similar applications.
The boiler condensate trap incorporates a seal of 75mm,
therefore it is unnecessary to install an air break and trap
in the discharge pipework.
3
1. The condensate outlet will accept 21.5mm (
overflow pipe. It is strongly recommended that thisdischarges internally into the household drainage system.
Where this is not possible, discharge into an outside drain is
permissible providing every possible precaution is taken to
prevent freezing.
/4in) plastic
Sink
450mm min*
Boiler
50mm per metre of pipe run
2.5° Minimum fall
ii) External termination via internal discharge branch
*450mm is applicable to
properties up to 3 storeys.
For multi-storey building
installations consult BS 6798.
e.g sink waste - downstream*
Pipe must terminate above
water level but below
surrounding surface. Cut
end at 45°
2. Ensure the discharge of condensate complies with any
national or local regulations in force. BS 6798 & Part H1 of
the Building Regulations give further detailed guidance.
3. The discharge pipe should be run in a proprietary drain pipe
material e.g. PVC, PVC-U, ABS, PVC-C or PP.
4. Metal pipework is NOT suitable for use in condensate
discharge systems.
5. The pipe should be a minimum of 21.5mm diameter and
must be supported using suitably spaced clips of the correct
design to prevent sagging.
6. It is advisable that the full length of condensate pipe is run
internally and preferably be less than 3 metres.
7. Internal runs greater than 3 metres or runs in cold areas
should use 32mm waste pipe.
8. External runs MUST be a MINIMUM of 32mm and fully
insulated with material suitable for external use.
9. If the boiler is fitted in an unheated location the entire
condensate discharge pipe should be treated as an external
run and sized and insulated accordingly.
10. In all cases discharge pipe must be installed to aid disposal
of the condensate. To reduce the risk of condensate being
trapped, as few bends and fittings as possible should be used
and any burrs on cut pipe removed.
*It is NOT RECOMMENDED
to connect upstream of the
sink or other waste water
receptacle !
17
7.0Site Requirements
Boiler
50mm per metre of pipe run
2.5° Minimum fall
iv) Termination to a purpose made soakaway
Boiler
iii) Termination to a drain or gully
Pipe must terminate above
water level but below
surrounding surface. Cut
end at 45°
Further specific requirements for soakaway
design are referred to in BS 6798.
500mm min
7.7Condensate Drain (cont.)
11. When discharging condensate into a soil stack or waste
pipe the effects of existing plumbing must be considered. If
soil pipes or waste pipes are subjected to internal pressure
fluctuations when WC's are flushed or sinks emptied then
back-pressure may force water out of the boiler trap and
cause appliance lockout.
50mm per metre of pipe run
2.5° Minimum fall
Holes in the soak-away must
face away from the building