SP-MAN-INSTALL-01
Revision 2 21-12-21
23
10.4
Filling the Sealed System
An air bleed vent(s) is fitted to the top of the boiler. Check that the vent plug on the top is screwed in fully, then unscrew it one complete
turn.
The procedure for filling the sealed system is as follows:
Only ever fill or add water to the system when it is cold and the boiler is off. Do not overfill.
1.
Ensure that the flexible filling loop is connected and that the double check shut off valve connecting it to the water supply is
closed. A valve is open when the operating lever is in line with the valve and closed when it is at right angles to it.
2.
Open the fill point valve.
3.
Gradually open the double check valve from the water supply until water is heard to flow.
4.
When the needle of the pressure gauge
(not supplied with boiler)
is between 0.5 and 1.0 bar, close the valve.
5.
Vent each radiator in turn, starting with the lowest one in the system, to remove air.
6.
Continue to fill the system until the pressure gauge indicates between 0.5 and 1.0 bar. Close the fill point valve.
7.
Repeat steps 4 and 5 as required.
8.
Check the Pressure Relief Valve
(See Section 10.6)
9.
Close the fill point and double check valves either side of the filling loop and disconnect the loop
10.5
Venting the Circulating Water Pump
It is important that the circulating water pump is properly vented to avoid it running dry and damaging its bearings. Please refer to pump
manufacturer’s instructions on how to vent the pump.
10.6
Pressure Relief Safety Valve (Not Supplied)
Now the pressure relief safety valve operation must be checked and set. The procedure is as follows:
1.
Check the operation of the safety valve by turning the head anticlockwise until it clicks. The click is the safety valve head lifting off
its seat allowing water to escape from the system.
2.
Check that the water is escaping from the system.
3.
Continue to fill the system until the pressure gauge indicates between 0.5 and 1.0 bar.
4.
Close the fill point valve and check the system for water soundness, rectifying where necessary.
5.
Water may be released from the system by manually operating the safety valve until the system design pressure is obtained. The
system design pressure (cold) should be between 0.5 bar and 1.0 bar. The pressure is equivalent to the maximum static head in
bar + 0.3 (1 bar = 10.2 metres of water), where the static head is the vertical height from the centre of the expansion vessel to
the highest point of the system.
6.
Now close the valves either side of the filling loop and disconnect the loop.
Sealed Systems
