IDEAL ISAR- NO CENTRAL HEATING

top banana · 20 Aug 2007

hello all,well i guess its that time of year when heating is switched on and problems occur!
have an ideal isar that is fine on hot water but doesn't supply heating.
i have overiden the radio signal from the thermostat but when the boiler has a 'c'on the readout the burner light flashes slowly but doesn't ignite.
any help please.

corgiman · 20 Aug 2007

Bet you its the diverter valve

Dan Robinson · 20 Aug 2007

Indeed. can't remember what the rest position of the diverter is... but...

hav it · 20 Aug 2007

dont they have that grey actuator box, that goes on at a funny angle, then twist and locks on..

Dan Robinson · 20 Aug 2007

No, that as the later Honeywell. The earlier ones had a Cp diverter valve, which worked the same way but has a diferent manifold and actuator.

Easy enough to change as long as adequate space and proper servicing valves where fittted.

gas4you · 21 Aug 2007

My money would be on the pcb, as boiler is getting signal for heat as in 'c' but is not firing. If it was firing but no heat then I would go for DV. PCB is notorious unreliable on these.

edit, maybe the thermistor/ntc for the ch is knackered. Worth checking first.

Agile · 21 Aug 2007

Since most of the internal operation is the same on DHW and Ch then its more likely to be the diverter valve.

With the boiler cold select CH and see if it fires up for 10-20 seconde to heat up the inside of the boiler.

The head can usually be taken off the diverter and the operating pin vigourously pushed up and down like external cardiac resusitation. That will often free it up for a few weeks!

Tony

gas4you · 21 Aug 2007

Yes but if the burner light is flashing slowly, then the boiler is thinking it is up to temp and just in circulating mode. OP says that it is going no further, fast flashing or lighting.

Another simple though OP, have you turned off mains for 30 secs at switched fuse outlet?

top banana · 6 Sep 2007

thank you very much for replies, i've just got back from summer hols and i'll keep you posted on resultsof your replies. thanks again.

the.ideal.man · 14 Sep 2007

Dan_Robinson said:
No, that as the later Honeywell. The earlier ones had a Cp diverter valve, which worked the same way but has a diferent manifold and actuator.

Easy enough to change as long as adequate space and proper servicing valves where fittted.

we dont make that valve anymore, if you have seen any of the boilers this year you will know all copme with the grey head!!

top banana · 10 Oct 2007

well,had to get the sparkys in as nothing wrong with boiler but apparently problems with thermostat etc.
if i get a better low down i'll post it!
thanks for all your replies

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IDEAL ISAR- NO CENTRAL HEATING

hav it

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