Idear isar HE35 no hot water, only CH

[beejpikey]

My Ideal Isar HE35 has stopped firing up when a hot water tap is turned on.
The boiler fires up and sends hot water to the radiators if I push the thermostat up high enough for it to kick in, so I know the boiler works., but only for CH.

I thought it might be the diverter valve, but this seems to be moving between CH and DHW fine.
My guess is the problem is something to do with the electronics not telling the boiler there is a hot water demand and so the boiler doesn't fire up.

Just to add that the boiler indicates only a "0" when switched on, and correctly shows a "c" and the ignition light is on when the CH kicks in. I have turned on and off, pressed the reset button but still everything is the same. As we had no need for the CH over the last couple of months the water pressure had dropped below 0.5, and there seems to be some air in the heating system but surely this shouldn't affect the hot water coming on, or does it?

Any help would be really very much appreciated. Many thanks.

PS The boiler was serviced in April 2013 by someone who seemed to know their way around the model and wasn't as critical of the boiler as my previous service engineers had been! Also the PCB was replaced about 3 years ago, hope it isn't that again...

 

[Dan Robinson]

PS The boiler was serviced in April 2013 by someone who seemed to know their way around the model and wasn't as critical of the boiler as my previous service engineers had been! Also the PCB was replaced about 3 years ago, hope it isn't that again...

Your service man obviously didn't know the boiler if he wasn't critical of it .

 

[Dan Robinson]

So if you run a hot tap the display remains "0"?

If so then I guess a duff sensor or the PCB.

 

[beejpikey]

Thanks Dan, I was actually pretty shocked when he didn't completely write the boiler off on seeing what model it was as I had never heard a good word about it! I will do more research next time around....

If it is the PCB again, what in the long term is my best action, get another PCB fitted, or change my boiler completely?

Thanks once again.

 

[beejpikey]

Yes, it just stays at "0" the whole time, hence my thinking something not right with the electronics, so sensor or PCB then.

 

[Dan Robinson]

I would lean towards the PCB personally.

Whether you want to throw that kind of money at the boiler is up to you.

Few other boilers out there can garner the unified hate of our industry.

Funnily enough though Ideal bought up the one of the other brand names known for abortions.

Surprised they left Ferroli, but then i think everyone has limits.

 

[beejpikey]

Just an update on this problem. I fitted a new PCB and the problem persists, no hot water when a tap is turned on, only CH seems to work.

I wonder if it is now the diverter valve...

I have a grey Honeywell head, which I have removed and the plastic slider on the side seems fine...not sure if there is anything else I can check without replacing it now.

Thanks.

 

[beejpikey]

And to add that I had an engineer look at it, who suggested the PCB after testing the thermistor which seemed ok. Obviously he wasn't sure either, but now I have ruled out the PCB I am at a loss as to what else it might be.

 

[Agile]

Just an update on this problem. I fitted a new PCB and the problem persists, no hot water when a tap is turned on, only CH seems to work.

I wonder if it is now the diverter valve...

Thanks.

Rather than wondering about whats wrong why not get a better engineer to diagnose what is actually wrong?

A fixed price repair might have been a better solution!

Tony

 

[beejpikey]

Thanks Tony, I have been on the phone to a couple of engineers, but have not managed to get a fixed price repair however think I have found someone who could do find the problem after explaining my current situation to them. Getting a new boiler is my only other option...which may be cheaper in the long run too!

 

[Agile]

Fixed price repairs come from Brit Gas or from Ideal themselves.

It is quite repairable but needs someone who knows how to diagnose faults on boilers!

Not the most reliable boiler though.

Tony