Problems with Baxi 105e combi despite new expansion vessel

[faithlies]

Hope someone can help please.

Had an engineer out in the week to replace expansion vessel on Baxi 105e combi boiler as the pressure kept dropping - we knew the expansion vessel was on the way out and had already had it pumped up once. He mounted the new vessel on the wall for easier access.

He also changed the PRV and replaced the wall thermostat, which he said wasn't communicating with the control panel.

Heating worked fine on Thursday and Friday.

Last night, heating turned itself off, water pressure had dropped again so added more (to be expected I suppose until system has balanced itself?)

Now this morning, heating didn't come on as timed, house is 9c Still had hot water though.

Checked boiler, tried resetting it several times and the pilot light just wasn't firing. This has not happened before.

In the end, I turned the dial to "hot water only" and it did fire, then quickly flicked it across to heating and hot water and now the heating has come on.

House is freezing though and will take a while to warm up and we just can't rely on it working for Christmas now.

Engineer coming back on Tuesday. Any ideas what this could be please?

I was just hoping that the system was settling after the work done on Thursday, but now I'm dreading it being unreliable again and it ruining the holiday.

 

[faithlies]

Getting really desperate here folks.

I've taken the thermostat off the wall and set it next to the control panel -- but still the receiving light on the wireless box isn't communicating (ie it isn't flashing "receive" every so often as it should). It was when it was fitted on Thursday, but I don't think this is the issue as the old thermostat didn't work anyway and heating still did.

Have turned the heating off twice today, turned it back on, nothing, it won't fire.

Have had to go back in the loft to the boiler and turn it off and re-set it, then turn the heating on again at the control panel, restart the boiler and it eventually fires.

 

[mcmarshon]

Try removing the wireless thermostat from your system to prove this out. Do the radiators actually get hot when you are doing all your resetting etc ?

 

[faithlies]

Thank you. I will try that, but I have just turned the thermostat down rather than turn the heating off again (I'm scared to turn it off in case we can't get it on again) and the temp in the radiators has reduced, so the thermostat is either working, or the boiler has conked out again.

I can't get back in the loft for the 20th time today to see which it is, so I'll wait for a bit and see if they start heating up again later.

The heating does work, but once it has been turned off, it won't come back on without resetting the boiler, and even then it is a gamble as to whether the pilot comes on at all.

I end up having to switch it off, leave it off for a bit, switch the control panel to heating off, then reset boiler, then press heating on.

This didn't happen before the engineer came out, the only problem we had was having the pressure keep dropping -- once you filled it again, the heating worked fine but only for a few days at a time before the pressure went again.

 

[faithlies]

I didn't actually touch the boiler at all today, heating has been on and off, getting hot then going off, getting slightly warm then going off, or not responding to the control panel at all.

I've messed about with the thermostat, reset it next to the control panel etc and eventually, each time, I was getting it working. But it was either going off itself or once I turned it off at the control panel, it wouldn't come back on.

Now, it stayed on fine overnight and the thermostat was working as we left it set low and the heating came on only to bring it up to temperature.

But once you turn the heating off at the control panel, it won't come back on properly without a lot of fuss.

So, I have removed the battery from the thermostat and it's worked ever since, obviously the heat is just blaring out but we were told the old thermostat wasn't working anyway.

What are the chances of the thermostat being faulty vs our wireless router interferring with it or something like that? Because we noticed the only times the heating worked yesterday was when we were not using our computers.

Alternatively, could the engineer have messed up the control panel, though it appears to be set up normally? It seems to be a problem in telling the heating to come on, once it is on the heating is getting hot so I'm not thinking anything mechanical?

 

[NatB]

Try changing the channel on your wireless router as multiple 2.4ghz transmitters will impact on each other.

 

[staffs]

We have had this before and it drove us nuts. Howeber turned out to be the secondary heat exchanger at the top of the boiler which was leaking and water was going down the condense line so therefore no visible leaks.

 

[45yearsagasman]

We have had this before and it drove us nuts. Howeber turned out to be the secondary heat exchanger at the top of the boiler which was leaking and water was going down the condense line so therefore no visible leaks.

Not on this boiler. You have got it all wrong, so why resurrect old threads.
Keep up.

 

[Agile]

Staffs, different boilers have different designs!

The problem you had was on your boiler!

Other people have different faults and the only person able to correctly diagnose the problem is the engineer at the boiler.

This thread is from 2009 and I am sure the fault was fixed by her engineer at that time. Its all long over now.

Tony