Gas vs Electric Shower

PinkSherbetPip

My fixed rate ends today and I’m rather stressed about it!  Over the last few months, we have been trying to reduce our spend and this has been easier having just had a smart meter fitted.  What I have no control over, is how long my teenagers spend in the shower when I’m out!!  So my question is, as we have both a gas and electric shower (8kW), which would use less energy?

Thank you

grumbler

 Very strange question... I thought everyone knows that gas is MUCH cheaper, even with not the most efficient boiler.

PinkSherbetPip

grumbler said:

 Very strange question... I thought everyone knows that gas is MUCH cheaper, even with not the most efficient boiler.

Well you certainly live up to your username!  If I had known the answer, I wouldn't have asked the question, but thanks for the response.  Nice way to welcome a new member.

Chris_English

PinkSherbetPip said:

My fixed rate ends today and I’m rather stressed about it!  Over the last few months, we have been trying to reduce our spend and this has been easier having just had a smart meter fitted.  What I have no control over, is how long my teenagers spend in the shower when I’m out!!  So my question is, as we have both a gas and electric shower (8kW), which would use less energy?

Thank you

For heating a given volume of water by a given amount the energy use will be the same, but in general, at the moment, gas is going to be far cheaper.

Just to check, though, I've not heard of a gas shower; do you mean a shower running off your gas boiler (or your hot water tank)?

FreeBear

grumbler said: Very strange question... I thought everyone knows that gas is MUCH cheaper, even with not the most efficient boiler.

Whilst gas is cheaper for heating water, it is not always the most efficient. If you have a system boiler, heating a tank of water for just one or two showers is wasteful if it has to be heated from cold each time. An electric shower in this situation would work out more economical.

With a combi-boiler, it is certainly going to work out cheaper to heat the water with gas.

PinkSherbetPip

Chris_English said:

PinkSherbetPip said:

My fixed rate ends today and I’m rather stressed about it!  Over the last few months, we have been trying to reduce our spend and this has been easier having just had a smart meter fitted.  What I have no control over, is how long my teenagers spend in the shower when I’m out!!  So my question is, as we have both a gas and electric shower (8kW), which would use less energy?

Thank you

For heating a given volume of water by a given amount the energy use will be the same, but in general, at the moment, gas is going to be far cheaper.

Just to check, though, I've not heard of a gas shower; do you mean a shower running off your gas boiler (or your hot water tank)?

Sorry, just to clarify, it is a shower running from the gas boiler, which is now quite old, no hot water tank.  We do have a combi boiler, but the shower doesn't run off this one.  We live in a terrace house, which used to be two back to back houses and we have a boiler in both the back and front.

QrizB

PinkSherbetPip said:

Chris_English said:

PinkSherbetPip said:

My fixed rate ends today and I’m rather stressed about it!  Over the last few months, we have been trying to reduce our spend and this has been easier having just had a smart meter fitted.  What I have no control over, is how long my teenagers spend in the shower when I’m out!!  So my question is, as we have both a gas and electric shower (8kW), which would use less energy?

Thank you

For heating a given volume of water by a given amount the energy use will be the same, but in general, at the moment, gas is going to be far cheaper.

Just to check, though, I've not heard of a gas shower; do you mean a shower running off your gas boiler (or your hot water tank)?

Sorry, just to clarify, it is a shower running from the gas boiler, which is now quite old, no hot water tank.  We do have a combi boiler, but the shower doesn't run off this one.  We live in a terrace house, which used to be two back to back houses and we have a boiler in both the back and front.

That's a trifle unconventional but (unless your gas-fired shower is uncommonly inefficient and/or delivers a huge flow rate) the gas will still be cheaper.

PinkSherbetPip

Thanks, I'm not sure about the flow rate, etc, so I think I need to look into this.  I suppose our boiler situation does seem unconventional, but it made sense at the time.  I think we kept things separate due to the output of the combi boiler and the fact that it was only a year old at the time.  Also, it meant that we were never without hot water should one breakdown.

QrizB

PinkSherbetPip said:

Thanks, I'm not sure about the flow rate, etc, so I think I need to look into this.

If it's a regular rose-on-a-hose shower you don't need to worry about the flow rate. If it's pumped and/or has multiple heads then give some details here.

Edit: this shower, for example, can deliver 21 litres a minute. Heating that much water will need (assuming mains water at 10C is heated to 40C) 42kW of gas. At that sort of flow, your 8.5kW electric shower might be cheaper.

PinkSherbetPip

Thanks. I'll need to check when I get home, but I think we have a Bristan Trinity 200mm shower head (it won't let me post a link).

Chris_English

That’s a new one on me, I’ve never come across a gas shower before.

Anyway, it’s nearly certain, given the difference in costs nowadays that it’s cheaper heating with gas, all other things being equal.

One reason that they may not be equal of course is that your electric shower may put out far less hot water than a gas one. I hate electric showers; where I grew up the incoming cold water would be around freezing, and the best that an electric shower could offer was a good flow of tepid water or a measly flow of sort of hot water, so they’d tend to come with heads with teeny-tiny holes in that put out something more like scotch mist than the waterfall I’d have liked.

So if that’s the two choices, a 9kw electric shower vs a 30kw gas one, then you may, in theory, be better off with the electric one.