Baxi Solo 3 Issue

[dilalio]

just swap the heads its just 4 Allen bolts and leave the old body in situ

Wish I could do that with the missus... But it'd be the body I was swapping!

 

[griffog]

if the pump connections are hard to access get the same pump and just swap the heads its just 4 Allen bolts and leave the old body in situ

Yup, that's what I did last time this needed replacing, much easier!

 

[stem]

If the pump wasn't moving enough water through the heat exchanger, the Overheat should trip. This stops the boiler (the pump continues) and a warning light comes on.

This has to be reset manually by turning the thermostat dial to the off position and then back to its original position. So you would know if it was happening.

 

[griffog]

If the pump wasn't moving enough water through the heat exchanger, the Overheat should trip. This stops the boiler (the pump continues) and a warning light comes on.

That definitely is not happening here. Boiler starts up, runs for a minute or so accompanied by increasing clanking from the feed or outlet pipes at the top and then shuts down. Overhead light does not illuminate.

 

[griffog]

As a follow up I decided it was time to call an expert in. Quickly diagnosed a blockage in the system and a failing pump. There was an almost complete blockage just above the pump requiring a short section of pipe to be replaced. Also the three way valve was corroded and the vent was similarly knackered due to corrosion. All parts replaced and now working again. Also moved pump further up as it was poorly sited (see earlier pics) with and fitted gate valves. Has advised a get the system flushed, hot water header in loft looked more like sewage than water

 

[stem]

Thanks for the update....so despite your thread title, no repairs to the Baxi required in the end then . Funny how the boiler always seems to get the blame, but in this case it was everything but . Odd that the overheat didn't trip though.....

 

[griffog]

Indeed, fair play to the Baxi, not the guilty party on this occasion. I have however now got a replacement PCB which I'll fit as a precaution.

 

[dilalio]

It's usually the system first and when that gets ignored, the boiler eventually goes kaput!

 

[Helping Hand]

In case anybody is interested the chattering relay problem which will eventually burn the relay contacts out is caused by failed decoupling capacitors on the supply rail. From memory they are the ones rated 47uf 100v and I think there are 4 of them, replacing these will fix most Baxi solo 2/3 control panel faults.

For safety reasons the pump relay is configured to always supply mains power to the pump unless the relay is activated to turn it off therefore is should always fail safe preventing over heating.