Cheaper to heat cylinder via gas or electric?

Juliebump92

Hi just a quick question, would it be cheaper to heat my hot water cylinder via the immersion? Or gas powered via the boiler? Or would it be cheaper to run with the immersion on 24/7?

southcoastrgi

just a quick answer, gas

Juliebump92

Thank you, will my airing cupboard still be as warm if I switch the immersion off and do it by gas?

rogerblack

Juliebump92 wrote: »

Thank you, will my airing cupboard still be as warm if I switch the immersion off and do it by gas?

Yes.
If the cylinder and boiler are not next to each other, the gas can end up at about as much as the electric, due to inefficiencies.
Set the hot water for a couple of hours a day, 12 hours apart, to minimise losses in the pipework if they are far apart.

Juliebump92

As I see, but we use a fair bit of hot water, is that going to mess things up if I switch it to gas? We currently use the immersion 24/7 and the airing cupboard is great for drying things out.

southcoastrgi

the heat in your cupboard will be more as the pipes from the boiler going to the cylinder will be hot, the cylinder will heat up quicker using the boiler, you could set the timer an hr before you need hot water in the morn & if you really need lots of hot water during the day then leave it on until an hr before you last use it, if you have a gas boiler then the immersion is only as a backup if the boiler breaks, it must be costing you a fortune leaving that on 24/7

Wywth

Gas is cheaper, unless you can take advantage of low rate electricity.

There's a MSE thread about the myths of keeping heating on 24/7
The same can be said for heating hot water

macman

You may have to reprogram your timing on the DHW side if you use a lot of hot water in the day. Otherwise a properly lagged tank will stay hot all day.
It's crazy to heat your hot water by immersion (especially 24/7!) if you can use your boiler. Gas is 4p per kWh, standard rate electrcity is 12p per kW-so it's about 300% more expensive.
Unless you are saying that you still have an E7 tarrff?
However you heat your hot water, your airing cupboard will still be warm due to heat loss from the cylinder and the local pipework.

David_Partington

If you need a quick top up you can just switch the electric immersion on for 15mins its usually quicker than the boiler. In fact its usually possible to have both on for rapid H.W. You elec bills may not be as bad as you fear because if you have the boiler on a lot the elec immersion will knock itself off on its thermostat a lot of the time because its already at the preset temp, although the reverse may apply if you hardly use the central heating also depends on C.H controls and how they are set.

HappyMJ

David_Partington wrote: »

If you need a quick top up you can just switch the electric immersion on for 15mins its usually quicker than the boiler. In fact its usually possible to have both on for rapid H.W. You elec bills may not be as bad as you fear because if you have the boiler on a lot the elec immersion will knock itself off on its thermostat a lot of the time because its already at the preset temp, although the reverse may apply if you hardly use the central heating also depends on C.H controls and how they are set.

It's not quicker. The immersion element is rated at 3kW. The boiler is rated at least at 12kW.

David_Partington

Yes but it depends on what else the boiler is heating and all sorts of other factors; i.e the starting point of the central heating water temp. Bear in mind the CH heats the water through a coil of hot water (in effect another radiator) wheras the immersion heater is directly immersed in required hot water.

So with gas theres a delay while it heats the water in the primary coil and anything else that is demanding hot water from the boiler, i'm not saying electric is more efficient just faster for the equivalent KW, unless you apply the flame directly to the cylinder....