Protherm 100 User Instructions - page 20
20
To replace gas valve
•
Ensure that gas supply is turned off at gas cock.
•
Remove gas valve module as described previously.
•
Undo nuts securing gas supply pipe between burner and
gas valve and remove pipe, taking care not to lose seal-
ing washers, see diagram 21.
•
Remove gas inlet connection to boiler.
•
Unscrew four screws securing gas inlet flange and gas
valve to its mounting bracket.
•
Remove gas valve by lifting upwards and out of boiler.
•
Fit replacement gas valve in reverse order to removal.
To replace burner
•
Remove burner as described in ‘Cleaning the burner’.
•
Fit replacement burner in reverse order to removal.
To replace domestic heat exchanger
•
Drain down heating circuit of boiler as described previ-
ously.
Drain down hot water circuit of boiler as follows:
•
From below boiler, close cold water inlet isolating valve.
•
Open a hot tap to drain hot water circuit.
•
Supporting the domestic heat exchanger, undo con-
nections and turn heat exchanger until vertical.
•
Manouvre heat exchanger up and forwards out of boil-
er, see diagram 22.
•
Fit replacement heat exchanger in reverse order to re-
moval, ensuring seals are correctly positioned in hy-
draulic block.
•
Open isolating valves on flow and return connections,
refill, vent and pressurise boiler. Check for leaks
•
Open cold water isolating valve. Check for leaks.
To replace overheat thermostat
Important:
Isolate boiler from electrical supply before this
Diagram 22
Diagram 21
Diagram 20
To replace pressure gauge
•
Drain boiler as described in
‘To replace pump’
.
•
Unscrew pressure gauge capillary pipe nut on right hand side of hydraulic block.
•
Unclip pressure gauge and pull out of lower front panel.
•
Fit replacement pressure gauge in reverse order to removal.