INSTALLATION
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Codensate Discharge
The condensate discharge hose from the boiler must have
a continuous fall of 2.5
o
and must be inserted by at least
50mm into a suitable acid resistant pipe - e.g. plastic waste or
overow pipe. The condensate discharge pipe must have a
minimum diameter of 22mm, must have a continuous fall and
preferably be installed and terminated to prevent freezing.
The discharge pipe must be terminated in a suitable position:
i) Connecting into an internal soil stack (at least 450mm
above the invert of the stack). A trap giving a water seal of
at least 75mm must be incorporated into the pipe run, there
also must be an air beak upstream of the trap.
ii) Connecting into the waste system of the building such as
a washing maching or sink trap. The connection must be
upstream of the washing machine/sink. If the connection is
downstream of the waste trap then an additional trap giving
a minimum water seal of 75mm and an air break must be
incorporated in the pipe run, as above.
iii) Terminating into a gully, below the grid level but above the
water level
iv) Into a soakaway
Note: If any condensate pipework is to be installed externally
then it should be kept to a minimum and be insulated with a
waterproof insulation and have a continuous fall. The total
length of external pipe used should not exceed 3 metres.
Some examples of the type of condensate terminations can be
found below.
1. Connection of condensate discharge pipe to internal soil
and vent stack.
2(a). Connection of condensate discharge pipe downstream
of a sink, basin, bath or shower waste trap.
2(b). Connection of condensate discharge pipe upstream of a
sink, bath or shower waste trap.
1
8
2
5
7
6
4
3
450
75
1000
52
Minimum pipe
gradient
75
8
2
11
12
≥25
4 3
9
6
10
≤ 3000
≥ 100
5
1
7
1000
52
Minimum pipe
gradient
≥ 100
75
1
4
6
2
8
9
10
≤ 3000
≤ 25
3
7
1000
52
Minimum pipe
gradient
1. Boiler
2. Visible air break
3. 75 mm trap
4. Visible air break and trap not required if there is a trap
with a minimum condensate seal of 75 mm incorporated
into the boiler
5. Soil and vent stack
6. Inverter
7. 450 mm minimum up to three storeys
8. Minimum internal diameter 19 mm
1. Boiler
2. Visible air break
3. 75 mm trap
4. Visible air break and trap
not required if there is
a trap with a minimum
condensate seal of 75
mm incorporated into the
boiler. In this case the
100mm is measured to the
trapin the boiler.
5. Sink, basin, bath or
shower.
6. Opem end of condensate
discharge pipe direct into
gully 25 mm min below
gratin but above water
level; end cut at 45°. Note:
the maximum external
condensate discharge
lengh is 3 metres.
7. Sink lip
8. Minimum internal diameter
19 mm.
9. Pipe size transition
10. Minimum internal diameter
30 mm
11. UV resistan, Water/
weather proof insulation.
12. Drain cover/leaf guard
1. Boiler
2. Visible air break at
plug hole- alternative
connection can be below
sink trap.
3. 75 mm sink, basin, bath or
shower waste trap
4. Sink, basin, bath or
shower with integral
overow
5. Open end of condensate
discharge pipe direct into
gully 25mm min below
gratin but above water
level; end cut at 45°. Note:
the maximum external
condensate discharge
lengh is 3 metres.
6. Minimum internal diameter
19 mm.
7. Pipe size transition
8. Minimum internal diameter
30 mm
9. UV resistan, Water/
weather proof insulation.
10. Fit drain cover/leaf guard.