Ideal isar 35HE DHW pre heat

[Robinh]

Hiya I have an Ideal isar 35 HE which brings up the Domestic Hot Water pre heat (t on the readout) about every 10 minutes instead of approx 2 hours. The result is the radiators upstairs are v hot all the time. Changed the DHW pre heat thermistor with no luck. Got me thinking that this could be the divertor valve because surely the DHW pre heat shouldn't affect the CH circuit. Any ideas anyone.

 

[LUNAT]

HI

you are right preheat function should not affect rads.diverter valve faulty.
replace the full kit and preheat problem should also be sorted.

 

[gas4you]

You need to check for any dripping hot taps or leaks on the hW pipe work. This will trigger the boiler into pre-heat as often as you are experiencing.

Turn off the cold water inlet to the boiler under the boiler and see if the pre-heat goes back to normal.

The rads getting warm upstairs/DV problem will be a seperate fault to this.

 

[superdupergasman]

You need to check for any dripping hot taps or leaks on the hW pipe work. This will trigger the boiler into pre-heat as often as you are experiencing.

.

Dont bother looking for a leak...its the divertor passing and not heating the domestic HE properly....very common...watch out as there are 2 different types of divertor cartridge on these.

 

[Robinh]

Thank you guys, changed the diverter valve and its cured the prob.

The old valve (only 2 years old) had a bit of gunge in it and was sticking but reckon it is servicable as a spare.