Installing a new shower- gas or electric?

jt118

Gas showers deliver more hot water per minute than an electric shower which is why they normally feel "better". But it takes a certain amount of energy to raise water temperature. (1Kcal raises 1 litre of water by 1 degree ). A gas shower running off a combi boiler will use more energy than an electric shower BUT that energy from gas will be considerably cheaper.(About 5p /kWh gas against 13p / kWh for electric) Therefore a gas shower using a 28kW boiler will cost about £1.40 per hour to run. and deliver over twice as much water as a 10Kw electric shower which will cost £1.30 per hour to run. BUT the Gas shower will deliver just under 2.6 times more water at the same temperature. (A modern gas boiler is about 93% efficent and a an electric shwoer near enough 100% efficient; so very little difference in efficiency). So unless your gas combi boiler is set to use a lower setting ie less kW for hot water the cost per hour is similar, BUT the amount of water and therefore the perceived comfort of the gas shower is greater.

jt118

To Add; if your combi gas boiler is fully modulating then it will turn down its gas useage to suit water flow (ie more for central heating less for Domestic Hot Water). Of course water flow then reaches the same rate as the electric shower but costs 2.6 times less per hour (53p / hour).

Therefore approximate Figures:
Gas combi boiler 10 litres per minute about 60p per hour; Gas combi boiler 23 litres per minute cost about £1.40 per hour. 10kW Electric shower 10 litres per minute cost about £1.30 per hour.

jt118

Just think about this in annual cost terms; a household of 4 people with a couple of teenagers and may well use a shower for about 1 hour per day, if so your electric or high flow gas shower will cost you £474.50 per year to run!!!!!!!!!!!!!!!!!!!!!!!!!

jt118

Last post on this subject your hot water from your boiler will have some cold water added at the mixer tap to get the water temperature to a reasonable level, therefore it if gas boiler is delivering 10 litres / min there will be an additional few litres from the cold. In the case of an electric shower the whole flow is heated to a reasonable level.

Gas 10 litres very hot water + say 4 litres cold = 14 litres flow warm water out. 53p / hour

Electric 10 litres cold in = 10 litres warm out; No Additional Cold Water. £1.30 / hour

Sublime_2

jt118 wrote: »

Last post on this subject your hot water from your boiler will have some cold water added at the mixer tap to get the water temperature to a reasonable level, therefore it if gas boiler is delivering 10 litres / min there will be an additional few litres from the cold. In the case of an electric shower the whole flow is heated to a reasonable level.

Gas 10 litres very hot water + say 4 litres cold = 14 litres flow warm water out. 53p / hour

Electric 10 litres in = 10 litres out; with no Additional Cold Water. £1.30 / hour

Are gas showers a lot dearer to buy, as they're obviously economical to run?

jt118

Prices vary hugely but gas will need a hot and cold supply so there will be additional plumbing cost, cold supply only to electric. Screwfix selling gas shower mixer unit for just £100.00 similar to electric shower price.

ukjoel

We have always gone with both.

Sounds silly but if your doing a bathroom from scratch the cost to put two in isnt that much more than the one and for me the key points are that while combi boiler powered is fantastic, spending that extra bit for peace of mind that I can have a hot shower every morning is worth it.

19times

I have a gas power shower and have noticed that the water doesn't seem to be as hot as it used to be. After two 5-10 min showers straight afer each other when my daughter gets in she says the water has gone cold. I have both the immersion on and the HW from the boiler 24 hrs. Does this make any difference? Where does the shower take the hot water from first

Thought about electric for guaranteed hot water but put off by extra installation costs/running costs/water flow?

Any advice please.

gavin246

I've had both and there is no comparison.

1. Electricity per unit is hugely more expensive. About 11p per kWh that means on a 10kW shower it costs 11p for every 6 mins shower. Say a family of 4 have 12min showers thats 22p a shower 88p a day £27.28 a month.

Gas on the other hand is around 3p a unit making the exact same showers cost £7.44 (excluding boiler efficiency new combi's can clock over 90%). Or if you spent the same money you could get 3.66 times more flow for the same money.

2. Simply a combi boiler can heat hugely more water than an electric shower. Just look at the difference in size between the two units and you'll get the idea.

3. For anyone with green thoughts most electricity in UK is made in gas powered turbines and sent through the grid. Through losses in the turbines and the grid (keeping those pigeons on the wires warm) 70% of the energy is lost by it gets to your house. So your effectively using three times the fuel and creating three times as much environmental impact for the same shower.

Note. I realise that combination gas boilers are very expensive and this initial cost is the only saving grace of an electric shower. As a note you can get an electric pump fitted to increase the pressure of older gas systems with a tank in the loft. They just come on when you turn the tap on.

Also some people can't get gas at all which is a shame. BTW I'm an engineer and know my numbers.

poppasmurf_bewdley

Our shower is supplied via an LPG Combi boiler through mixer taps fitted to the bath.

We have also fitted a little 'widget' given away free by Severn Trent Water which fits between the mixer taps and the shower hose which regulates the pressure and keeps it constant. Since fitting this, with the water temperature control set on the boiler to it's lowest setting, all we have to do is turn the hot water tap on and the water is perfect for a shower.

Before we fitted the widget, we had to fiddle around with hot and cold to get a suitable temperature and water flow but that's now a thing of the past. :j:j:j