my ideal classic boiler ff270 fires up even when no heat is called for. i.e. when the programmer for the ch and hw is in the timed position but 'off' i can hear water passing through the pump and the boiler periodically fires up. it also fires up if i turn the bioler thermostat up to 6 from its normal 4 position and then cuts out if turned back down. the system seems to work fine at other times when heat is called for. any ideas.
has the boiler got a frost protection thermostat on it? this will make the boiler fire up if faulty or below the set temperature.
dr andy bartle
December 2009
thanks for your coments, the two port valves are about 12 years old, the programmer is new so i think that can be ruled out so will try the wire test on the zone valves. thanks.
ezayid
December 2009
Its a zone valve sticking, disconnect orange wire from each valve in turn until it stops coming on and that will tell you what valve microswitch is sticking.
32yrs in gas
December 2009
do you have 2 port valves in the airing cupboard (above the pump)if so are they old?
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