Please help, no heating despite three "repairs"!

[faithlies]

We have a Baxi 105e boiler, no more than four years old.

Expansion vessel replaced 10 days ago, we knew it was on the way out, pressure needed to be topped up every week then every few days, heating otherwise functioning fine.

Had new wall-mounted expansion vessel added and new thermostat (wireless) as engineer realised old one wasn't communicating.

Thermostat didn't work though, engineer came back, said the router was interfering with it, moved it away from router, seemed to work for two days.

Then heating stopped working reliably, hot water is fine.

Heating often won't come on, whether thermostat is in use or not. The times it does come on, it heats up and then switches itself off. Boiler is still on and making noises.

Engineer came out for third time today, first blames dripping tap as he said the hot water light keeps flashing which means the boiler is heating water secondary to putting heating on. Taps all turned off tight, so that's not the problem.

Then he says the new wall mounted pressure vessel means we have lost the pre-heat function the original pressure vessel provided -- not too happy about that and were never told about it, but turning off the pre-heat function doesn't help.

Now he has said the valve which switches between the hot water and heating isn't working properly? And that he has to order parts and we've now got to freeze until Wednesday morning, with heavy snow due tomorrow.

I'm sick of this, the heating was working fine other than the pressure issue before the expansion vessel was changed.

Any other ideas anyone? Is it worth calling someone else out? Is it a coincidence that this valve has seized and we have only had problems since the boiler was first "repaired" ten days ago?

We are freezing, any advice welcome.

 

[Agile]

You are lucky to get anyone to come today!

Fitting an external EXV will not stop the preheat function, in fact you will get more preheat volume.

Continually topping up will have caused dirt in the water and that may have now caused the boiler to fault.

Radio stats can often be tempermental. I prefer to fit wired ones.

Its quite likely there is a further fault with your boiler.

You dont state your location! Getting someone else could depend on that.

The last forecast for my area showed no snow and its 4.7° outside now.

Tony

 

[theheatinghelper]

sounds to me that hes not a repair specialist, he could have disconnected the stat to see if that was the problem, the valve he talked about at the end is the diverter valve, i say to people if it make take time to get parts is that you can always get the boiler manufacturer out to repair you boiler .. it maybe a little bit more expensive but its more than likely they would have the part readily available. the dripping tap kicking in the flow switch is something i've never heard of, the new external pressure vessel should have no effect whatsoever with the pre-heat. As for the valve being a coincidence ... maybe ..maybe not .... it could be just "one of those things" i would think about getting a second opinion though!

 

[faithlies]

Thanks both.

He categorically stated that the external EXV would not have the pre-heat function. This is a British Gas engineer we're talking about

Am I right in thinking that now I've got the heating fired up and working (which is more than he managed) and the problem is this valve he's on about, that if I don't use the hot water tap the CH should stay on?

My thinking is if I'm not making that valve move to hot water, it should stay in the CH position?

As for thermostat, I've had the damned thing on and off for ten days.
It works intermittently. Engineer today said it worked, well it worked while he was here but I've disconnected it again now as it isn't communicating with the control panel at all, as far as I'm concerned it's another potential fault that I can keep out the loop.

Heating seems to be more likely to come on if thermostat is disconnected.

 

[faithlies]

Scrap the idea about the hot water tap. The green "heating on" light on the control panel has gone out Heating has gone off.

This is what it keeps doing, when it does start to heat up, it just turns itself off one the rads get hot

 

[tonybhoy]

Are you still getting hot water?

If so I would be looking at the heating sensor, NTC.

Tony

 

[faithlies]

Yes, DHW is fine.

I was thinking something like that. Or what about the PCB? Would the DHW still be functioning ok if it was a PCB fault?

I've pressed the "heating on" button again and for once the thing has come back on (usually the only wauy of getting it back on once it has heated up once is the cut the power for a few minutes, leave it and then start again). Rads are red hot now, but no doubt it will go off again shortly.

It's just so intermittent, it would probably be less annoying if it was completely broken and didn't work at all, then I wouldn't keep trying to make it work

 

[tonybhoy]

Well your boiler is working in the sense that the divertor valve, microswitchs, fan, aps, pump, gas valve are all doing thier job so it is going to be a sensor issue or perhaps a faulty PCB with something on the board not connected properly or loose, a relay or something.

But the fact that you can bring the heating on by turning the boiler off means your resetting it (a stat or overheat stat or something).

Could even be a sticking pump.

Tony

 

[faithlies]

Well your boiler is working in the sense that the divertor valve, microswitchs, fan, aps, pump, gas valve are all doing thier job so it is going to be a sensor issue or perhaps a faulty PCB with something on the board not connected properly or loose, a relay or something.

But the fact that you can bring the heating on by turning the boiler off means your resetting it (a stat or overheat stat or something).

Could even be a sticking pump.

Tony

Thanks Tony. Difficulty is suggesting these things to the so-called experts, especially when you're a girl

You won't believe it but the stupid thing is now pumping out heat, full on (no thermostat) and has been for over two hours, longest time it has worked for several days

You watch, it'll work fine now until Wednesday until it gets messed with again

 

[tonybhoy]

Tony

Thanks Tony. Difficulty is suggesting these things to the so-called experts, especially when you're a girl

You won't believe it but the stupid thing is now pumping out heat, full on (no thermostat) and has been for over two hours, longest time it has worked for several days

You watch, it'll work fine now until Wednesday until it gets messed with again [/quote]

Write every single thing down no matter how insignificant you think it is.

EG, what was the boiler light status when it did A or what was going on when it did B that sort of thing.

Listen for odd noises or noise that are not what your used to when your boiler is on and write that down too with times etc.

Engineers hate that sort of thing but it definately works. I had a problematic boiler last month and the woman wrote every single thing down and between the two of us, over a period, of about two weeks we pinned the fault down which was a relay on the board shorting out.

I told her what to watch for and when etc and she diligently recorded everything.

Tony.

 

[faithlies]

I will, thank you.

It did seem it was a bit noisier than usual but now it is working (for now) it is back to normal noise-wise.

No chance that it could be something daft like air in the pump? Worth trying anyway?

 

[gas4you]

Sounds like and external control fault from here. I would want to disconnect the new stat from the boiler and link out the terminals.

If it fires all the time, then it is not a boiler fault.

 

[faithlies]

Sounds like and external control fault from here. I would want to disconnect the new stat from the boiler and link out the terminals.

If it fires all the time, then it is not a boiler fault.

Sorry not sure what you mean, the thermostat has the batteries removed and is not functioning, it is an ex thermostat as far as I'm concerned, I'll be putting the thing in the bin tomorrow.

The boiler doesn't fire all of the time, just sometimes after a full power down and reset.

Sod's law, heating has been on full tilt since before 3pm now. I'm leaving it on and I've turned the downstairs rads down, (we have been out for the evening, the wine is making me warm as is the house).

I'd rather cook than freeze! Though we haven't touched a hot tap for all this time , I'm thinking maybe it really could be the valve the gasman talked about?

 

[Agile]

Thanks both.

He categorically stated that the external EXV would not have the pre-heat function. This is a British Gas engineer we're talking about

If its BG then they are doing the work on a fixed price basis or an annual cover arrangement.

In that case you just have to pester them to sort it out for them.

I am rather surprised they did not replace the internal EXV for you. Thats odd for BG.

Its true that the external EXV will not become a heat store but the internal one will continue as a heat store and with added volume as being failed it will contain no air.

Tony

 

[Baxi-Remeha]

Sorry not sure what you mean, the thermostat has the batteries removed and is not functioning, it is an ex thermostat as far as I'm concerned, I'll be putting the thing in the bin tomorrow.

so u took the batteries out of the stat and wondered why your heating wont work.....


which light on the boiler is comming on when your getting heating??

sounds like either you have an external controls problem, or maybe a stat kicking the frost protection in.

or maybe the divertor valve is passing and your getting ch when its trying to do the preheat..