Hot Water only or H&W more cost efficient?

jessilu1

Might sound like a daft question but is there a big difference in cost on my Glow-worm boiler to turn the heating and water on for a couple of hours each day or to just have it switched to heat water only!

I have the timer set to turn the H&W on for an hour in the morning and again at night for an hour, but is it greatly more cost efficient to just have it heat the water and have no heating?:)

notbritishgas

Yes it is more cost effective to just have the hot water on.
If the water circulates round the radiators it loses heat which then has to be heated up again by the boiler.

macman

You may have noticed that your gas bill is higher in winter when the CH is on?

Pincher

I try to use the programmer so that the hot water is heated when not heating the house, like 5am. This means that when I want to heat the house, all the heat from the boiler is applied to the radiators, so the house warms up quicker.

Some systems plumb the bathroom towel radiators into the hot water circuit, so they will get hot even in summer. This is to keep your towels dry all year round, and to provide a circulation bypass should all the other radiators have TRVs and are closed automatically.

jessilu1

Thank you everyone Pincher I never thought of that , what a good idea, I'll be doing that from now on. Thanks muchly :T

jrrowleyws

Pincher wrote: »

I try to use the programmer so that the hot water is heated when not heating the house, like 5am. This means that when I want to heat the house, all the heat from the boiler is applied to the radiators, so the house warms up quicker.

Thats actually inefficient as you're heating up the boiler components straight from cold.

If you're still using heating then the best way is to have the hot water on just before or just after the heating, then the boiler only has to heat its components once. But to be honest, the boiler should have enough capacity to power them both simultaneously, especially as the water volume for the hot water is significantly lower than for heating so doesnt impact that much.

Either way, you're going to make very little difference in gas usage!

cybergibbons

Pincher wrote: »

I try to use the programmer so that the hot water is heated when not heating the house, like 5am. This means that when I want to heat the house, all the heat from the boiler is applied to the radiators, so the house warms up quicker.

I'd question any advantage this brings. For 95% of the time my heating is on during the year, the room and boiler stats will be coming in and out as the boiler will be sized to deal with a negative temperature day.

I could use the remaining capacity to heat up water, and avoid any losses due to cycling.

Pincher

jrrowleyws wrote: »

Thats actually inefficient as you're heating up the boiler components straight from cold.

If you're still using heating then the best way is to have the hot water on just before or just after the heating, then the boiler only has to heat its components once. But to be honest, the boiler should have enough capacity to power them both simultaneously, especially as the water volume for the hot water is significantly lower than for heating so doesnt impact that much.

Either way, you're going to make very little difference in gas usage!

The idea is not to save gas, but to get the room(s) warm quicker after I hit the BOOST button. I go in and out of the house at irregular hours, so I don't want to keep the heating on all the time. When I do want it, I want it quick, i.e. from when I walk in.

Pincher

cybergibbons wrote: »

I'd question any advantage this brings. For 95% of the time my heating is on during the year, the room and boiler stats will be coming in and out as the boiler will be sized to deal with a negative temperature day.

I could use the remaining capacity to heat up water, and avoid any losses due to cycling.

I try to only switching on the heat when it's actually cold.
On good days in winter, my windows are wide open.