Worcester 47-406-54

Pre-Installation
6 720 811 922 (2014/07)12
In situations where there are likely to be extremes of temperature or
exposure, the use of a proprietary trace-heating system for external pipe
work, incorporating an external frost thermostat, should be considered.
If such a system is used, the requirement to use 32mm pipe does not
apply. However, all other guidance above and the instructions for the
trace heating system, should be closely followed.
Fig. 12 Soak away
Fig. 13 Condensate pump to external disposal
3.5 PRESSURE RELIEF PIPE WORK
• The pressure relief drain pipe (1) from the boiler should be at least
15mm diameter copper pipe and run downwards, away from any
electrical equipment or other hazard, preferably to an external drain
or soak away.
• The pressure relief drain pipe (1) should be finished with a partial
bend, near the outlet to face the external wall (as shown) to help
prevent freezing.
Fig. 14 Pressure relief pipe work
NOTICE: Unheated internal areas.
▶ Internal pipe runs in unheated areas such as lofts,
basements and garages should be treated as
external runs.
NOTICE:
▶ The pressure relief valve is a safety device for the
boiler and if activated may discharge boiling water or
steam through the relief valve drain pipe.
▶ Care should be taken when siting the outlet pipe so
that it does not cause an obstruction or discharge
above a window, entrance or other public access
where it could cause a hazard.
13
14
10
500mm min.
25mm min.
400mm
min.
1
12
11
9
6720644744-11.2Wo
9
10
*
25mm min.
14
13
1
7
6720644744-12.2Wo
*
2Outside wall
1,3 Drain pipe
4External drain
Table 10 Key to fig 7
6720643895-08.1Wo
1
2
3
4