Theromstat In New Home

[slid_away]

Hi All
I'm hoping someone can help with this
We moved into a new home back in May and I thought I had sussed the central heating out, but with it being May, the heating didn't start to come on until recently so now I'm baffled.
We have 2 thermostats, one in the lounge and one in the main bedroom.
The one in the lounge is set at 18.5 and the one in the bedroom is programmed to be at 18.5 most of the time but an hour before bed it is set to come on at 21 degrees.
What is happening though is the upstairs is not getting warm even when the bedroom thermostat drops below 21 at the desired time. It will only come on if the heating it on down stairs.
My way of thinking was that both thermostats work independently of each other and either one would fire up the boiler. Its worth noting that the bedroom boiler, when it reaches it's desired temperature , it clicks ( I assume the valve?) and the panel lights up with a flame indicating it is on, but still all the radiators remain cold.
If I were to go downstairs and turn that thermostat up, then the upstairs heating will come on.
I'm not sure if I'm being stupid and missing something but I don't see the point of having 2 thermostats if one controls upstairs and downstairs anyway.
Any advise is greatly welcome
Kind Regards

[ivor4781]

one boiler.. one thermostat.not two

[donny48]

You can have a two thermostat system, as well as switching the boiler on/off they also operate automatic valves that as an area gets up to temperature can shut down while still allowing heat to another area.

[slid_away]

Thank You Donny. Seems I may need to get an engineer in to look at it then

[donny48]

These systems are complicated to pipe up and even worse to wire up, definitely not a job for the amateur to attempt to trace faults. Right decision to call in engineer, surely you must be still under some form of warranty. At very worst you might be doing something wrong with the controls, I doubt you are, so ask his advice and watch what he does.

[slid_away]

Thanks again Donny. I think we are still covered by the housing developments warranty so I'll give them a call. Definitely something not right there.

[Garaman]

It could be a fault, but it could just be that the system is configured so that upstairs is an optional addition to downstairs. In the latter configuration, the downstairs thermostat would be controlling the boiler, and the upstairs thermostat would control a valve. That sort of arrangement would mean that you could set the upstairs to switch off at a lower temperature than downstairs, but never higher, and you could never have the upstairs on without the downstairs. Might sound odd, but most people would prefer the upstairs lower, or off even, most of the time to conserve energy.

[alavahalf]

As you know hot air rises and the bedroom is probably warmer than you think. The stat in the bedroon may well be stopping the zone valve from opening and heating the bedroom.
It is quite normal these days to have a thermostat on each floor.
Have a glance at this .. it will save me typing.

http://home.howstuffworks.com/home-thermostat4.htm

[Hard@it]

Is it possible that one is frost stat and the other a room stat. Why don't you turn them both to the highest and let the thermostatic radiator valves, (if you have them), control the individual rooms. Meanwhile if one stat has a lower setting, set it to 5 and set the other to say 25 and see if the system runs.
The only other possibility could be is that the stats are controlling individual zones.

[slid_away]

Many thanks for your answers. I have tried that hard@it, but it still didn't come on.
Garaman, seems like the answer and certainly makes a lot of sense. I'm getting the company out to look at it just in case though.
Thanks for the info alavahalf
Appreciate all your time in answering. Many Thanks

[slid_away]

Problem is fixed...it was wired incorrectly and working fine now :-)