20
L
N
PUMP ELECTRICAL CONNECTIONS
Fig. 5-5f Wiring Connections
Note
Older systems need careful checking as
they will be operating at a higher pressure.
Note
The expansion vessel is factory set at 1.5
Bar.
5-5.9 Wiring
The wiring of the pump should be done by the installer to best suit the system timer/
programmer.
IMPORTANT
The pump MUST be wired so that it is ON at all times the Boiler is ON.
INST
INST
INST
INST
INSTALLA
ALLA
ALLA
ALLA
ALLATION 5
TION 5
TION 5
TION 5
TION 5
2
LIMIT STAT
CONTROL STAT
C
2 1
C
L
N
BL
BR
GY
BL
GY
R
TO BURNER
PREWIRED
BR
GY
MAINS SOCKET
PREWIRED
BL
L
N
GY
LIVE BROWN
EARTH G/Y
NEUTRAL BLUE
5-5.10 Cold Fill Pressure
The Cold Fill Pressure of the central heating system should be:-
Recommended Pressure - 2 Bar Max. Pressure - 3 Bar Min. Pressure - 1 Bar
It is advised to use a pressure gauge when filling the system to ensure correct pressure.
5-5.11 Expansion Vessel Pressure
The pressure of the expansion vessel should be set at 0.5 Bar below the cold fill pressure.
This should be done prior to filling the system using a conventional car tyre gauge and
pump.
IMPORTANT
The pressure of the expansion vessel cannot be checked when there is
water in the system.
5-5.12 Filling the System
1.
Switch OFF electrical supply to the Boiler.
2.
Check all drain cocks are closed.
3.
Check spare sockets on the Boiler are plugged.
4.
Connect the filling loop.
5.
Open the filling loop isolating valve part-way so that the system fills slowly.
6.
When full and vented make a note of the cold fill pressure on the Boiler pressure
gauge.
7.
Open drain cocks and vent to fully flush the system.
8.
If required, set the expansion vessel pressure to 0.5 Bar below the cold fill pressure
recorded in 6 above.
9.
Check all drain cocks are closed.
10. Refill and vent the system to the correct cold fill pressure see 5-5.7.
The correct amount of suitable corrosion inhibitor should be added to the system
strictly to the manufacturer’s instructions.
11. Shut filling loop isolating valve and disconnect one hose union.
12. Check for leaks.
55555
WIRE TO SWITCHED
PROGRAMME LIVE
