Thermostat turns heating off downstairs but still comes on upstairs

[Kimberley_125]

Hello I am hoping someone can help. We currently have a combi boiler and the heating is controlled by a thermostat in the living room. We have recently moved into the property so are unaware if there were any problems before. I have programmed the thermostat so that the heating should be off all the time. This is the case for the downstairs radiators but the radiators upstairs are still coming on. This is at random times of the day/night and there doesn’t seem to be a pattern. I have had to close all the valves to stop the radiators coming on and boiling! However I have left the bathroom one on to monitor the problem, trying different settings on the thermostat to see if this makes any difference but no!
Does anyone have any ideas, is this a plumbing problem or an electrical one?
Thanks in advance.

 

[Gasmk1]

sounds like a pipework problem you need someowne to do an investigation on your system could be a couple of problems

 

[Kimberley_125]

Thank you, that helps to narrow it down as I wasn't sure if this would be a plumbing issue or an electrical one.

 

[Riley]

Daft question there isnt another thermostat upstairs is there

 

[SimonG]

Any recent work done on the boiler or system?

 

[Kimberley_125]

Not a silly question at all. I searched everywhere for one just in case but there is only the downstairs one. We have only just moved into the property but no previous work as far as I'm aware of and the boiler is only 4 years old. I am wanting to replace the thermostat as well but wasn't sure if it's best to do this first or get the problem solved first and foremost?

 

[Riley]

Well easy task would be to remove the thermostat and see if the problem still occurs. If not you know that it's the thermostat if it does then you know that you need someone out to look at the boiler

 

[jtsplumbing]

Strange fault, combi should only fire for heating when called for, sounds more like an control problem something is telling heating to work , What make boiler & Controls do you have ?

 

[Riley]

Where is the boiler and are there any particular times when the heating comes on i.e. if you're running a bath or having a shower

 

[jonnyswamp]

Do all the upstairs rads come on and are they all the same temp (roughly by touch)
And as Riley says above, does this coincide with hot water usage, if so you'll need someone to look at the boiler
How big is your house, beds etc
Do the downstairs rads warm up at all
What stat have you got, RF (wireless) or hard wired

 

[Kimberley_125]

 

[Kimberley_125]

I have attached some pictures so hopefully this helps. The boiler is an Ideal Logic + and the thermostat ESI ESRTP RTP Programmable Room Thermostat.

The boiler is in the loft and there is no pattern to the heating coming on upstairs in relation to the running of hot water etc seems to be at random times. All the readiators also seem to be the same temperature to the touch.

I've tried to look online but I'm not getting anywhere, seems a complete mystery.

 

[jtsplumbing]

Well that's quite a good boiler with long warranty, may be a good idea to get Ideal out to check boiler under warranty B4 you start spending any money.

 

[Stoney Ground]

Well that's quite a good boiler with long warranty, may be a good idea to get Ideal out to check boiler under warranty B4 you start spending any money.

Is their a frost/ pipe stat in loft kicking it in when temp drops near boiler.

 

[Kimberley_125]

Thank you for all your replies. Just an update. Unfortunately the boiler was just out of warrenty but I have purchased a new thermostat which is on the way. Although there is no frost pipe I have monitored the situation more and although the radiators are on at various times they are actually boiling hot when we have run the hot water a while such as having a shower. Not sure if this sheds any more light on the mystery?

 

[thereisawizza]

Try turning the "preheat" setting on the boiler to the off position, if this cures the fault it pin-points a fault with a boiler part which is then an easy fix for a GSR fitter.

 

[Riley]

Yep. You need a GSR engineer

 

[Last Plumber]

What kind of boiler is it ?
Does it have a preheat on the hot water ?
It's unusual but I have known the diverted valve to pass slightly ( giving a low flow rate to heating circuit), and when the preheat is running it will pass into heating circuit.

Bit of a shot in the dark I know but if it does have preheat on the hot water side the user manual will tell you how to turn it off. Try it for a few days and see. If this gets you anywhere, you need a heating engineer to look at the boiler for you.

Hope I'm on right track and this helps you.

 

[Kimberley_125]

Thanks again all. Sorry it takes a while to reply the boiler is currently up in the loft and each time I try something I need to wait until someone is around to climb up there for me! It's an ideal logic + boiler. I've attached a pic further up the thread if this helps. Turned the pre heat off yesterday and although the radiator isn't boiling hot anymore it is still warm at the bottom where the water would flow into the radiator. Therefore I'm not sure if turning off the pre heat has helped to pinpoint the problem or not?

 

[Riley]

Sounds like you still need an engineer to take a look

 

[Last Plumber]

It does sound like the diverter valve is passing.
When you run hot water it will still pass into the heating circuit.
If it's not as hot now you've turned the preheat off, I think the valve is still favourite, without having seen it obviously.
A good gas safe registered engineer will be able to sort it, even if it's something different than we think.
My advice is to find someone who's been recommended and remember, ask to see their gas safe i.d. card ! He or she will be proud to show it to you, as it cost a lot to get it.

 

[Riley]

Careful with the advice you offer buddy this poster may not DIY but someone else searching for the subject might

 

[Last Plumber]

Point taken,
My apologies .