baxi 105e - again!

[alwest197]

Hi, I've got a baxi 105e which is causing me some issues. It started with the DHW going cold and then hot again then cold again. I cleaned out the DHW HE to no avail so bought a new one and fitted that to no avail. The hot/cold thing only happened intermittently. Recently the 60 degree light is flashing and no hot water at all, the rest switch did nothing but I found that by turning off/on the electrics made it work again. I thought the system might be sludged up so bought some Fernox cleaner and left it in the system for a week. When I drained and flushed the system some dark matter emerged but not a lot. Whilst the system was drained I took out the Primary HE and cleaned it, again very little debris came out (I serviced the boiler at the same time). I also removed the pump head (the flashing 60 degree light suggests that either the water pressure is low or the pump is not working) again no issues it rotates ok and no debris.

On putting it all back together everything was working for a while then it went back to the flashing light. powering off and on again brought the system back to life. I have no problem with the CH this works all the time.

I have changed the DHW thermostat, no difference. I have also changed the diverter valve diaphragm and pin. Although the valve seems to be working ok even when the DHW does not turn on the flame.

Other things I've noticed both the DHW and CH seem to be rather hot and turning down the dials seems to have little affect.

So I'm a little perplexed as to what to try next.

Any assistance gratefully accepted as ever.

 

[alwest197]

Forgot to mention it had a new PCB about 2 years ago.

 

[James1991]

Are you gas safe registered?

 

[alwest197]

I think the answers in the title of this forum.....DIY.

I never touch the gas side only the water and electrics.

so any ideas?

 

[45yearsagasman]

Alwest197,the fact that you've accessed the combustion chamber to remove the primary heat exchanger means that you have " touched" the gas side which includes parts within the combustion chamber. I doubt you'll get much joy from the professionals on the open forum......that's why you were asked if you are Gassafe registered.

 

[gasright]

Did you check the Flux capacitor while taking out the Main Heat Exchanger?

 

[James1991]

I think the answers in the title of this forum.....DIY.

DIYnot you mean!

 

[alwest197]

interesting..

I've been using this site for years.. but you seem to have become be a self appointed Health and safety team.

If you cannot or do not want to answer the question may I respectfully, because I appreciate the expertise that's out there, request that you do just that.

Whilst its actually non of your business what I am or have done.... I will tell you that I'm a fully qualified Millwright and electrician. That said I am not a 'safe gas registered' qualified person.

I must be careful when cleaning my open gas fire next time as it appears to be part of a combustion chamber..

I'll leave it at that as it seems, at least on this question, I will not be getting any assistance.

Thanks for all your help in the past.

 

[alwest197]

Sorry I forgot... The flux capacitor is working well... see you in the future

 

[45yearsagasman]

Don't be offended, there was none intended. It is a policy of the site that no gas related advice is given. I realise there are many competent guys out there, but it's a blanket policy and is there to discourage any diy gas work. Good luck in the future.

 

[alwest197]

ok, thanks for your reply.. I have to admit to getting a bit bitter and twisted as I've always had helpful advise from the site in the past.

I've ordered a new micro-switch which may or may not be part of the cause but it was a suggestion from another site.. I fear its more likely to be a new PCB required...

I may just have a new boiler fitted..instead

thanks again.

 

[gasright]

All that time and money you've wasted!

Why don't you just get someone who's competent to repair the boiler?

 

[gasright]

It's not the Microswitch, though it is a common fault on a boiler that looks like a 105.

 

[ScottishGasMan]

You mean get a new boiler so you can install it yourself because it might work then?

As said, no DIY gas info, Someone expirienced with this boiler could have sorted it in one or two visits with minimal parts. And they would have been able to check it was safe.

Hope you dont have kids, as if the boiler or the fire become dangerous with you messing about with them the CO will affect them first.

 

[mfarrow]

First to the last... If you are worried about water being too hot get the PCB cover off and check the gubbins move when you turn the dial - I believe the shafts go right through the PCB/potentiometers so you'll see anything amiss without needing to take the PCB out. The shafts are loose and may have been lost on the last replacement.

The flashing light needs proper diagnosis. If the light flashes whilst the pin is fully up and engaged then it's likely a PCB fault but you need to confirm the switch function in this event using a multimeter. PCB faults are common and the newer design can suffer from dry joints at the connector blocks. This is more likely to be intermittent than a switch fault.