Boiler Internal Drain; Pressure Relief Pipe Work - Worcester GREENSTAR 35 CDi Installation, Commissioning And Servicing Instructions

Minimum hole size for the condensate soak away must be
400mm deep by 300mmØ .
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.
NOTICE: Unheated internal areas.
▶ Internal pipe runs in unheated areas such as lofts,
basements and garages should be treated as external
runs.
*
1
500mm min.
13
14
9
11
12
Fig. 12 Soak away
14
*
1
7
Fig. 13 Condensate pump to external disposal
3.5

BOILER INTERNAL DRAIN

The CDI Classic has the facility to drain the water direct from the boiler
through the condensate pipe.
If the boiler uses a soakaway or a condensate pump:
▶ Use an external drain point on the system to prevent excess system
water being drawn through the soakaway or condensate pump.
6 720 812 175 (2014/07)
3.6
• 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.
• Pipe (1) should be finished with a partial bend, near the outlet to face
the external wall (as shown) to help prevent freezing.
9
1
10
2
25mm min.
3
400mm
min.
10
4
13
Fig. 14 Pressure relief pipe work
2
1,3
4
Table 12 Key to fig 7
25mm min.
6720644744-12.2Wo

PRESSURE RELIEF PIPE WORK

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.
1
2
3
4
Outside wall
Drain pipe
External drain
PRE-INSTALLATION
2
6720646608-123.1Wo
13