BAXI 105 HE Pump Noise

[davidha1]

Hello,
Can anyone help please? I have a BAXI 105 with a whining noise that sounds like it’s coming from the pump. It starts after the central heating has been on for around 30 minutes, as soon as you turn the hot tap on it goes off. I was going to change the pump head but after reading a few posts on here I’m not sure if that is it. Some say the hot water washer, diverter o rings, pump etc..
It is a fairly new diverter (3-4 months).
Any help appreciated.
Thanks
David

 

[ianmcd]

Hi David

Would be surprised if it was the pump head but would have to be in front of the boiler to be sure, the pump on your boiler circulates at the same speed no matter if it is heating CH or HW, the diverter valve when in CH mode can cause that as the CH water gets hot , there are service kits available for the diverter valve and are not expensive, and nothing prohibits you from doing it yourself on that boiler, but if you do make sure you cover the PCB bousing with cling film or something and a towel, they are terrible when doing that for any water to get straight into the PCB housing

 

[davidha1]

Hello Ian,

Thank you for taking the time to reply and the advice on the diverter. I learned the hard way about water going on the PCB - I had to use a hair dryer . I said I would never do another one ha ha. It was a cheapish valve off eBay, false economy I guess.
Any tips on how to diagnose it with the front off?

Regards

David

 

[ianmcd]

Hello Ian,

Thank you for taking the time to reply and the advice on the diverter. I learned the hard way about water going on the PCB - I had to use a hair dryer . I said I would never do another one ha ha. It was a cheapish valve off eBay, false economy I guess.
Any tips on how to diagnose it with the front off?

Regards

David

Best way is if you have a long screwdriver or similar, that you can touch the boiler with and put to year ear, we call it a listening stick and when the boiler is making the noise you will hear it loudest where the noise is being generated from, beleive it or not but water supply companies use a similar method to detect water leaks, very old technology, but it works, ebay can be OK to buy spares off, but when they say refurbished they meat removed from an old boiler and cleaned up doesnt mean it didnt have problems, for a competent DIYr installing the service kit is not a big job, many videos on youtube to see how easy it is

 

[davidha1]

Thanks Ian, I remember doing that on cars years ago (I’m old haha) I will try that tomorrow.
Cheers again for taking the time to help.