Pressure Relief Valve; Expansion Vessel; System Filling And Pressurising - Baxi Combi 130 HE Installation & Servicing Instructions Manual

Double
Stop
Check
Valve
Valve
DHW
Mains
Inlet
Fig. 3

Expansion Vessel

removed for clarity
Fig. 4
Expansion Vessel
Discharge Pipe
Fig. 5
Stop
Valve
Temporary
CH
Hose
Return
Pressure Relief
Valve
6.0 System Details
6.3 System Control
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 the Baxi Intellistat, is
recommended.
6.4

System Filling and Pressurising

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.
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.
5. To aid removal of air from the system whilst
filling, move the diverter valve to the CH position by
using the installer parameters (see Section 10.5).
6.5 Expansion Vessel - CH only(Fig. 4)
1. The appliance expansion vessel is pre-charged
to 1 bar (10 lb/in 2 ). Therefore, the minimum cold fill
pressure is 1 bar. The vessel is suitable for correct
operation for system capacities up to 125 litres
(27.5gal). 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".
6.6 Pressure Relief Valve (Fig. 4 & 5)
1. The pressure relief valve is set at 3 bar,
therefore all pipework, fittings, etc. should be
suitable for pressures in excess of 3 bar.
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.
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