As said depends where the stat is assuming the rads are the correct size.
If the t/stat is cycling it will take a long time.
Is the t/stat in the room you are measuring?
The thermostat is in the room I'm measuring. How can I tell if it's cycling?
In my book a room should warm up from stone cold to nice in less than half hour.
Your problem is probably a combination of:
draft
heat from rad cooling off against cold window
often heat getting trapped behind curtains
improper balance
soil
unsersizing
Draughts may be a problem, but do we keep the door closed.
The curtains are usually closed by the time the heating is on full, and I always make sure that no heat is getting trapped behind them.
The system is probably out of balance, but the rad does get very hot anyway.
What do you mean by soil?
How do I work out what the correct size rad should be?
In my house never. If boiler is on 80 degrees all day we can achieve 18.5 max if that is of any help to you.
It's a matter of aclimatising.
Are you saying your system won't heat above 18.5c at all even if it's on all day? Sounds as if something is wrong there.
I take your point about aclimatising but I'd like to know if I'm throwing gas at a problem I'm never going to solve if you know what I mean.
i.e 1hr 45mins from 16 - 21C. (slower than I thought actually).
For info, the outside temp was 6C at the time.
One of the reasons I'm fitting a thermal store actually, heatup times are slow.
Much better than mine, so there's something wrong somewhere as we seem to have similar sized rads. What's a thermal store?
The official definition was if the OUTSIDE temp was minus 1 then the house should be at 21 degrees inside in an hour .
That's what I wanted to know, which means I've got a problem somewhere.
Have you considered larger radiators... normally helps.
Is your room stat in a warm area i.e. near a rad. If it is then it may think the house/room is up to temp. when actually it isn't.
Haven't had the thermostat long, and tend to keep it on the coffee table in the middle of the room. It's definitely not near a rad.
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Thanks for all of your comments. How hot should a rad get at full blast?