Splitting UFH from main boiler circuit

[whoschuffed]

Mister Banks is correct, I have a fallback temperature of 4°c less than normal... which I currently run at 18°. The floor comes and goes as it's wants, in November it was once a day (usually in the morning) now it's more often now it's colder.

So are you saying you have your thermostat set to come on at 18c all the time or 4c less than 18c?

 

[Rodders53]

I'd never want UFH again... probably.

My oil fired system is on for 3 hours in the morning now, 0730-1030. Any earlier and the oil burner wakes us; it is in the garage under our bedroom (UFH manifolds also in garage). Then it has a 2 hour top up run at 1300-1500. It's set to come on again at 1800 but may or may not be required - or in the kitchen and hall only. (All loops pass through the lounge so warm that room and the plasma TV is a useful heat source this time of year). The Kitchen-diner, large, vaulted roof, needs a boost from the air to air ASHP for breakfast.

Rooms are. in winter, a bit cool very first thing but comfortable, otherwise. If the sun hits the Lounge and Kitchen they can overheat so I do need to manually tweak things to keep my better half happy temperature-wise.

The system was designed and installed by who have managed to leave cold patches on the floors where other parts are toasty. Incorrect thermostats (no day/setback) and the previous owner fitted a timer-thermostat with proportional control that used to switch things on and off far too often (thermal actuators are not instant on/off flow controls). I'm now using it as a dumber time switch effectively and it works better for how we want than when we arrived here.
There are other design anomalies: Hall and WC on same loop but WC 'freezing' no floor to speak of to emit heat. Ditto Kitchen and Utility (small cold room, off a warm kitchen).

 

[Mr Chibs]

Well, up to a week ago I was having the fall back to 14°c

One morning in particular, the batteries went flat in the thermostat, and when I got up in the kitchen it was cold.

Decided to try leaving it on 18°c all the time, yes, that means in the night it may come on, but my train of thought, is perhaps it's more efficient keeping the slab warm rather than doing a bit heat-up every morning.

As a coincidence I've just had the heating bill/usage through and I'm nearly a third lower on gas usage.
Previously I'd been setting the thermostats to around 19°c but being on 24/7 it seems permanently warm.

Might be a fluke, but I will run this way for another month to see.

 

[whoschuffed]

Well, up to a week ago I was having the fall back to 14°c

One morning in particular, the batteries went flat in the thermostat, and when I got up in the kitchen it was cold.

Decided to try leaving it on 18°c all the time, yes, that means in the night it may come on, but my train of thought, is perhaps it's more efficient keeping the slab warm rather than doing a bit heat-up every morning.

As a coincidence I've just had the heating bill/usage through and I'm nearly a third lower on gas usage.
Previously I'd been setting the thermostats to around 19°c but being on 24/7 it seems permanently warm.

Might be a fluke, but I will run this way for another month to see.

I've just been firing things on and off manually before today but have today tried to keep a constant of around 17c throughout the day and our usage according to the IHD so far is around £9.50 today which is quite a lot (inc electric but ive only had the sonos on briefly and some lights briefly), that is taking nto account a big warm up this morning at 5:30am when my partner got up for work no doubt.

I may try and leave it on 16c or 17c over night tonight to see what it is like tomorrow morning.

Whenever its been around 15c the Nest thermostat gives a time estimate of when it thinks it will reach your desired temp and its pretty much always wrong.