Is under floor heating really expensive to run?

[Newnamefornow12]

We moved to our new house last week. Thier is a garage conversion and the only heating in it is underfloor heating. We will be using this room as a playroom so will likely have the heating on in there alot! I'm just wondering if anyone with underfloor heating has found it really expensive to run? Never had it before. Still awaiting the dreaded first bill's for this house! Thanks x

We’ve got underfloor heating and don’t find our bills too high.

Is it a wet system or is it electric? Our wet system in the extension doesn't cost much (less than a radiator would) but the electric underfloor heated floor in the shower room costs a fortune.

Electric underfloor heating is horrendous. We have it in a shower room and only run it for 2 hours a day on economy 7 because it's so pricey. We didn't buy a house which had it in the kitchen/diner for that reason.

Energy from electricity costs more than four times as much as energy from gas.

So if you mean "is electric heating expensive to run?"

then the question is "yes"

If you have information about your underfloor heating you just need to find out the wattage output (if it's electric) measure the size of the space that is heated and cost per unit from your supplier.
Eg ours runs at 140w / m2 (which is quite typical)
Currently our electricity cost is 13.4295p /kWh
Our heating mat is a total of 18m2
So 140w/m2 X 18m = 2520w per hour /1000 = 2.52kw per hour X 13.4295p = a running cost of 34 pence per hour
Remember to measure the area that is actually heated and not the whole of the room. Ideally there shouldn't be furniture covering the heating mats.
This link could help you figure out the cost www.ukpower.co.uk/tools/running_costs_electricity
Hope that helps

We have underfloor heating throughout the downstairs of our house and we don’t find it particularly expensive. The cheapest way to run it is to keep it on all the time (except summer when it’s off obviously!) and just keep it low, turning it up on really chilly days.

Stillwatchingfriends that's a debatable one and I'm not sure which way I go on that. Check out the following link and click on 'should I leave the heating on low all day' www.moneysavingexpert.com/utilities/energy-saving-myths/#heatingon

Gettingin that information is for regular central heating. Not underfloor, which is different and is more efficient if left on all the time.

"Not underfloor, which is different and is more efficient if left on all the time."

can you explain the calculation?

If its electric heating it's expensive. If it's a wet system it's the most efficient and comfortable way to heat your home. How the water is heated is another matter.
Ps. I.m a plumber

Heating from gas will be phased out. Electric will be the way to go.

If it's electric your meter will turn like it's in a spinning class. I had this in a kitchen for comfort heating and had to stop using it as the bills here crazy. If its gas heated, it will cost more than rads but should be manageable. Gas will be around for a long time yet, as electric systems are still no where near as efficient. And there's nothing on the horizon, that will change this.

Generally running costs will depend on how well insulated the house is and the cost of energy which depends on the fuel (electricity being four times the cost of mains gas).

Garage floors are frequently built 150mm below the floor level in the house - so hopefully when they did the conversation they put down something like 80mm of insulation then 50-60 mm of screed (concrete) with UFH pipes in. Add say 10mm for carpet or tiles and you raise the floor 150mm making it level with the floor in the house. 80mm is about the minimum amount of insulation you should have under UFH. More would be better. Some self builders are using 200mm.

Was building control approval obtained for the conversion? It should have been and if so building control rules mean it should have insulation on the walls.

Worse case would be if they didn't involve building control, put no insulation in the floor/walls and went for electric UFH. That could indeed make it expensive to run.

Sister had electric UFH for her kitchen. First Bill was astounding and has been switched off since. Having her gas heating extended in now so she has a radiator in there.

We have wet gas UFH. Brilliant and economical

Just for info..

There is a good energy cost comparison site that compares different fuels. It takes into account the efficiency of the boiler or heat pump.

Scroll down to the table. The column headed "Pence per kWh (after boiler efficiency)" is the one to look at.

nottenergy.com/resources/energy-cost-comparison/
.
Its possible to argue with their figures because there are so many different tarriffs available but its still the only one I know that compares different fuels.

Interesting the electricity produces more CO2 than gas per KWh.

Interesting the electricity produces more CO2 than gas per KWh
That would depend how the electricity is generated, so very difficult to quantify.

I've sent an email to ask them why. Data here..
www.ofgem.gov.uk/data-portal/electricity-generation-mix-quarter-and-fuel-source-gb
..suggests we make a lot of our electricity from gas and most of the rest comes from fossil free sources. So the average for electricity should be lower than that of gas not higher.

If I get a reply I will post here.

The efficiency of heating your house using electricity generated by burning gas a hundred miles away, sending it to you through a huge transmission and distribution network, then turning it back into heat, is poor. This is why, in your house, the cost of energy from electricity is more than four times the cost of energy from gas.

At the time I write this, 32% of the electricity the UK is using comes from large Gas stations. 10GW

Wind is unusually high at 25%. 7.6GW

Nukes are 22% 6.9GW

When usage increases in the morning, gas will be cranked up (you can't turn up the wind) to about 20GW

www.gridwatch.templar.co.uk/
Online display from the National Grid.

The answer to your question is no not fundamentally more expensive than radiators, but depends on the usual factors such as how much insulation as it's even more critical with ufh, and whether it's powered by gas, electric, heat pump, etc

As expected, big gas has been cranked up to 21. This is approaching its max. Nukes still at 6.8, they are normally run full on, night and day, if they are in good working order, as there is negligible incremental cost, they will sell into any market, no matter what the price.

Wind has dropped a bit to 6.6

Solar is negligible because its cloudy.

Coal fired are at 1.6GW, which is very little. During the summer they were about zero as they were mostly closed down. This will be to have them hot and ready to fire up if needed, as the big gas stations have little capacity in reserve, nuke is at max, and wind cannot be increased.

Other sources are fairly insignificant.