Typical problems with instant water heaters are
- not enough water flow to raise the gas valve; cure is to improve the water pump flow rate.
- pilot light not up to the duty: cure is to use a pricker (available from Calor gas shops) to clean the jet.
- flue not working properly: cure is to inspect and improve (especially the flue termination where it goes outside)
The main difficulty you may have is getting your repair work past the Boat 'Safety' Scheme. You are supposed to use original spares only.
I had to junk a perfectly working Vaillant heater because my installation, in a sea-going boat, so NOT subject to BSS, could not meet BS PD 5482-3.
Roger Morgan
September 2009
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