Baxi HE 105 Intermittent Hot water Problem

[hatstand69]

Hi All,

I have a 3 year old Baxi HE 105 which has started to only give hot water sometimes and most of the time when the C/H is running and even then it’s not guaranteed.

I’ve read around on the internet and changed the diaphragm, (the 3” one) and cleaned the pushrod and ensured they are coming out fully an smoothly, which they are. But no change.

I have read that cleaning the DHW heat exchanger is worth a try but, would only do this if somesome advised me to.

Before I pay BG a £168 guaranteed fixed fee. Can anyone recommend what I could change or try first. I’m competent with plumbing, but not a plumber so have my limits.

 

[heytesto]

Does the hot water demand light come on when you open a tap? Try operating the microswitch with you finger.

 

[hatstand69]

The hot water is working this morning. It wasn't last night. So the demand light comes on (the one with teh tap sign) as well as showing that it's heating up to 50.

I'm sure it doesn't light when it's running cold though.

 

[fitz1]

probably dhw diaphram

 

[hatstand69]

Thanks for the reply. I thought it was the diaphram as well and changed it. Still nothing.

Just as an additional point. The HW seams to always work first thing in the morning, which would suggest a temperamental thermostat?

Any other idea's I could try.

 

[namsag]

More information is req.
When you get no hot water leave the tap running and go and look at boiler what lights are on, is the HW demand light on are there any other lights flashing for instance the one on fan/flue fault which is your 50 degree light this suggest faulty intermitent air pressure switch

 

[hatstand69]

Sorry for the late reply. Called away to work. Thanks for the pointer. I've ordered the part (Part Number 248466, for anyone who has the same problem). I'll post back the results when I've fitted it.

Here's hoping!