Baxi Combi Instant 105E -water pouring out

[lemmy999]

Been having an intermittent issue with the DHW recently. No hot water in shower some mornings. Shutting shower off and then turning back on sometimes cured it, sometimes not. Turned boiler off, did the reset and it would come back up, hot water- great. Sometimes the 60 deg light would flash showing fault on pump or low pressure

Checking here the consensus was probably the diaphragm and or microswitch so I thought I'd check/replace them. Unfortunately I bought the wrong ones ( didn't realise the Instant is so different to the standard 105E ) Anyway on Wednesday I drained the system down, removed the diaphragm and found it to be good. The switch however is well flaky so my intention was to replace that on Saturday. Re-assembled and refilled the system.

I'm working away from home and got a call from my wife to say that water was p*ssing out of the boiler. Luckily my lad was at home. He knows a bit about boilers and reckons the leak is to the left of the heat exchanger.

Oh and to cap it all I reckon the PCB got very wet as well during this episode.

 

[Terry lambert]

Dry the PCB thoroughly with a hairdryer before putting power back through it

 

[lemmy999]

It may be too late on the PCB front- the RCD banged out whilst I was doing my long distance triage

 

[Terry lambert]

Dry the PCB and the harness/ all electrical parts thoroughly

Check fast blow fuses on board and system 3amp fuse.

It's worth a punt

 

[lemmy999]

Well it looks like I might have got away with it on the PCB. Checked it out, looks nice and dry. Few spots of water about but none actually on the board. Ran the wife's hairdryer over everything for 10 minutes just in case.

That only leaves the leak to deal with. Sons said that he reckoned the water was coming from the left hand side if the primary heat exchanger or the associated pipework. Is my best choice to slowly pressurise the system again and see if i can spot the leak?

Further question. When I drained the system to look at the diaphragm I just used the filling loop to refill. Is that the right thing to do or have I over-pressurised the system?

 

[lemmy999]

Update- just re-pressurised the system. Confirmed the leak is coming from the pipe to the left hand side of the heat exchanger. I have read on the forum that there are O rings in the joint between the pipe and the heat exchanger. How difficult is it to change them? Looks to be a bugger though as there is not much room between the casing and the heat exchanger

 

[bazdaman]

You should not be in the combustion chamber! They are easy enough to do though with practice!

 

[lemmy999]

You should not be in the combustion chamber! They are easy enough to do though with practice!

I have decided to get an engineer in to do the job. Looks to be a devil of a job and not one that I personally fancy.