Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Remove the cap from the expansion vessel Schrader valve
Drain the boiler central heating circuit
Drain the boiler central heating circuit
Observation:
Attach a foot pump to the Schrader valve of the expansion vessel and check the air charge pressure is approximately 0.75 bar.
Isolate as per TOPs P4
and refit as necessary