Stupid question about Thermostats...

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...before I call someone out.
I have an old Baxi boiler, I have a care plan with them which has proved useful over the last few years and everytime they come out they mutter about it becoming too old to source parts so i'm expecting to have to replace sooner or later.
A year or so ago they fixed an issue and because the thermostat I had wasn't working properly they gave me a baxi one. which was great!
I wasn't there when the engineer explained the thermostat so i'm working off the principle of the previous one (you tube only reveals a guide in French https://www.bing.com/videos/search?...BF52EAA82BCF197BF544BF52EAA82BCF&&FORM=VRDGAR and I can find no manual)
Basically my issue is that we cannot stop the heating coming on even if its too warm. the only way we can switch it off is turn the boiler to hot water only. (fine in Summer but not useful now)
Can you check my understanding of the thermostat before I call someone out?
  • we have set the clock
  • we have set the timer to come on for an hour in morning, 4 in evening
  • Sun symbol, my understanding is that we set this to a temperature that if exceeded the heating turns off even during programmed period?
  • Moon symbol, my understanding is that we set temp to a figure where heating comes on if drops below?
  • Winter/snow symbol, i'm really not sure what this does!
  • on/off symbol, again confused here, seems to turn thermostat off but boiler happily chugs away?
The Baxi care plan is good but i'll have to go through a number of stages to get someone out and if its as simple as me not understanding the thermostat i'd rather not start the process, your advice would be appreciated.
 
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Room thermostats are not all the same and some have different functions. Trying to use a new thermostat based on the instructions for the one it has replaced is unlikely to provide you with the information you require. If you post the model details of the new Baxi room thermostat on here, someone should be able to point you in the direction of some instructions for it.

It seems that you may have a programmable thermostat (ie one that provides both time and temperature control) You don't give much detail about your existing heating system system, but this type of thermostat is more usually fitted to a combi boiler. You say yours is an old system and most of those tend to have separate hot water cylinders for stored hot water, if so it would be unusual to install a programmable thermostat on a system like this if there is also a separate programmer elsewhere providing time control of hot water and heating.

Regarding the symbols. The sun symbol will be the normal daytime temperature that you wish to maintain. The moon symbol is probably a 'night setback' which allows a lower temperature to be maintained during the night. With some thermostats this is entered as a temperature, others as the number of degrees lower than the set daytime temperature.

Winter / snow symbol will probably be 'frost protection' which will turn the heating on automatically if there is a risk of the plumbing freezing regardless of any other settings.

So in summary. You will need the correct instructions for the thermostat you have now, and if you have a programmable thermostat with separate time control elsewhere that is a bit of a bodge as can interfere with the set timed operation of the new thermostat.

I'm an electrical engineer, not a gas engineer, but I believe that a Gas Safe engineer is obligated to leave instructions for any new controls with a customer after installation, so that may be a recourse. If that's wrong, I'm sure one of the Gas Safe guys will collect me.
 
You should have been given the user manual for your thermostat. If this didn't happen, contact the service company and ask them to send you a copy.

The link you provided shows a Viessmann 30e thermostat. Does yours look exactly the same?

Which make/model boiler do you have?

Be wary of someone who tells you the parts are no longer available. They may be economical with the truth and looking to earn commission for selling a new boiler. If this happens, post a question here and you will get an honest answer.
 
Many thanks for your Replies, apologies for the vagueness...

Its a combi boiler.
The model is exactly the same as the video, but I believe it's branded as Baxi
(apologies, not in front of either at the moment)

To be fair to the Baxi Engineers who have come out, they've pointed out that there are some parts they'd struggle to replace rather than giving me a hard sell on a new one
They gave me a free thermostat, I didn't question not getting a manual. I have tried looking online for one but couldn't find the exact model.

Based on the information you have given me, I think we are using the thermostat correctly, so the boiler shouldn't be coming on during the day and should be turning off when its to hot, so I suspect a callout is required.
thanks
 
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just got home and no surprises, heating is on, even though the temp is high and the programmed on time hasn't been reached.
Everything is as i described, the only odd thing is that the moon symbol is showing, suggesting that it thinks its the middle of the night?
but i'm still confused as to why the heating is on
 
Thanks, I rang them today and they couldn't find a manual either!
I've tried looking for a manual for the viessmann one but no luck
They are sending an engineer who will probably say we've not set the thermostat correctly!
 

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