Underfloor Heating and Heating Water

bobs99

Hi All,

I wonder if you could help. Myself and my partner recently moved into a small property which has underfloor heating and a Timer for Hot Water. Neither of us have much experience with either of these kinds of systems as we both had constant hot water and standard gas central heating in the past.

Based on assumptions we have been leaving the underfloor heating constantly on, even when out of the house but just at 15 degrees which we assume means that the system wont be using any energy to sustain. From our understanding turning the system off and on is actually less economical than just leaving it at a constant low comfortable temperature but then spiking it briefly to 18-2- degrees to heat up the apartment when home. Is this assumption correct?

We also wonder if there are any guidelines as to how long the water should be heated. So far we have set the timer to heat for an hour in the morning and about 45 mins after work. We are wondering if there are any ways to figure out on average how much that may cost us.

Many thanks in advance for the advice!

Laurensalive

I know B and Q sell under floor heating. Why not look on there site to see if there are any guidelines. Either that or go into store as mine does have a display with under floor heating. B and Q should have some leaflets regarding this too.

MallyGirl

I certainly wouldn't run the UFH all day if you aren't there. I love my UFH but it costs a bomb to run. Just program it to come on before you get up, go off half an hour before you leave and back on before you get home - how long before depends on how intelligent the controller is and how big the space to heat is.

bobs99

Hi,

Thanks for the replies. I guess my question comes down to: Does it not cost more to heat up from scratch every day?

I only ask because our electrician advised not turning it off and on for this reason but he admitted he doesnt have UF heating himself.

Smiley_Dan

Wait a minute... is this electrical or wet UFH?

The thing with UFH is that it runs at a much lower temp than rads. But the heat needs to come through the floor covering (which is?) and also conduct down into the floor (I hope there's insulation in the floor) and so can sometimes take a long time to respond. That's why a lot of advice is there to leave it on a long time.

There are a lot of variables.

Regarding "does it not cost more to heat from scratch" see the thread on heating water 24/7. The answer is that it uses less energy, but whether that means it's cheaper or not depends on how you generate and pay for energy (sorry to sound vague).

Maikeru

Is this a modern type of underfloor heating (which runs off peak rate electric or gas) or the older 1960s type that heats up the concrete floor (on an off peak electric rate e.g. Economy 7)?

I have the latter in my house and leave it on all day during the winter - it's turns on itself during the off peak hours and turns off during the peak hours. The concrete floor basically acts as a massive storage heater and retains the heat during the off peak hours.

If you have modern underfloor heating it would be mad to leave it running all day; would cost a fortune.

macman

Your assumption about 'heating from scratch' is completely incorrect: the longer you leave it on, the more it will cost. UHF is no different in this respect to any other form of heating. It may well be more comfortable to leave it on for longer, but that is an entirely different question.