"Andy Hall" wrote in message news:47717409@qaanaaq...
On 2007-12-25 20:05:25 +0000, "Arthur2" said:


"Andy Hall" wrote in message news:47716036@qaanaaq...
On 2007-12-25 18:31:37 +0000, "Arthur2" said:

What do you mean by "fires up"? Fan runs and burner lights?

Does it run at full power or low power? Presumably if it is firing
up
as in the burner lighting, after a short while the burner goes off
because
heat is not being transferred to the hot water?




When a hot tap is turned on the boiler fires up as in makes the usual
noises..then
remains like this until the tap is turned off, as though its running fine
except the water
remains stone cold.

So the heat has to be going somewhere. What happens if you turn down
the room thermostat and then run the HW? My guess would be that the
radiators will get warm.

If so, it suggests the diverter valve inside the boiler that directs the
primary (heating) circuit water to the heat exchanger instead of the
radiators. A common fault is that they stick.

I don't know anything about low or high power.

Many boilers have variable output power. On high output the boiler is
usually making more noise because of the fan running faster.



Should it be easy to see if the burner lights up?

If there isn't a sight glass then check the meter.



Just checked the manual and it points out the cut-off button. There seems
nothing to lose by trying it but it
seems to be stuck unless we're supposed to apply a heavy action to it.

Arthur