Installation manual

MAINTAINING TWIN FLOW

All gas appliances must be serviced at least annually

by a CORGI registered engineer. This should include :

Water Heater

• Isolate electrics and valve off hot, cold, and gas to unit.

• Check the water filter and strainer to be sure there are no blockages.

• Remove the combustion fan and clean the impeller.

• Check the burner for wear or water damage. Vacuum out any debris.

Wipe out chamber.

• Check the heat exchanger for soot or hot spots that could be caused by

poor combustion.

• Clean carbon build up from ionisation and ignition probes.

• Check flue terminal for blockages or potential blockages, check that flue

is in good condition.

• Check all electrical connections are reconnected

• The gas pressures should then be re-set. The procedure is detailed in

the water heater manual.

• Verify temperature control by checking temperature at outlet, keep in

mind that there will be pipework losses.

• Check all gas joints inside the unit with an electronic gas detection

device when starting unit.

• Leak check all joints back to the service valve for commercial

installations, or tightness check the system in domestic properties.

Boiler

• Isolate electrics and gas

• Clean inside of casing with soft cloth

• Remove combustion fan and burner assembly

• Remove burner cassette check for damage, cracks etc. If cracked

replace complete cassette. Clean with soft brush and vacuum cleaner

• Replace all gaskets: burner, fan, and heat exchanger.

• Check venturi and gas/air distribution plate for dirt and clean

• Check heat exchanger for dirt, if necessary clean with soft brush and

vacuum cleaner. Taking care to prevent dirt falling back into the heat

exchanger. FLUSHING THE HEAT EXCHANGER FROM THE TOP

DOWN IS NOT PERMITTED,

• Check ignition and ionisation probes clean if necessary and replace if

cracked.

• Refit all components

• Check condensate drain to ensure it is not blocked

• Check flue to ensure it is clear

• Reinstate electrics and gas supply

• Fire boiler and check all safety devices

• Check combustion if alteration to the combustion is required refer to the

boiler manual