ideal isar no heating

[luke060]

hi, i have an ideal isar which does not heat the water. the controls are calling for heat because the boiler displays d when the hot water tap is opened, but the burner dosent stay on for long before it cuts out. i can just about manage a warm shower, if i turn the water flowrate down to a bare minimum.

 

[petit_pablo]

Does heating work? Does heating get hot when you run a hot tap?

Favourite culprits would be plate heat exchanger / diverter valve / thermistor

 

[luke060]

hi thanks for the reply
just tried running the hot tap for about 5 min, the rads did not warm up. they do get hot when in c/h mode

 

[petit_pablo]

Does the boiler come on for a bit then go off then keep repeating that when the taps on.

 

[luke060]

yer thats what it does... the pump remains on but the burner comes on and off about every 30 sec

 

[petit_pablo]

Most likely to be a blocked plate heat exchanger then.

 

[luke060]

thanks petit,
can this be removed and cleaned i.e with a pressure wash or somthing?

 

[petit_pablo]

It can be removed and cleaned although they are very fiddly on the isar.

Cleaning with spirit of salts or a central heating cleaner should do the job. Search the forum for cleaning plate heat exchangers, its been done to death before.