Cost difference between New gas boiler heated water and a power shower?

worded

Anyone know the approx. difference

I have a power shower upstairs and another connected to the emersion downstairs.

Considering getting rid of the power shower.

Also approx. how long does it take a modern gas boiler to heat water?

Thanks

air

You may as well keep it unless you have another reason to remove it. Use the regular shower during winter when you're running the boiler anyway and the electric shower in summer. It's not really worth running a boiler in summer to heat hot water unless you're having really long showers.

Dardania

OP: length of heating time depends on a couple of factors (basically around the size of the cylinder, and kW of coil): a 30 minute run should be adequate

On a point of clarity, when you say power shower, do you mean one that generates it's own heat?

And when you say heated by immersion, do you mean one that takes it's water from the hot water cylinder? And is that hot water cylinder heated by electric immersion element, or from the gas boiler?

air wrote: »

You may as well keep it unless you have another reason to remove it. Use the regular shower during winter when you're running the boiler anyway and the electric shower in summer. It's not really worth running a boiler in summer to heat hot water unless you're having really long showers.

Don't know if I'd agree with the second part of your statement - heating water with gas is about a third of the cost compared to electrical: of course, it presumes good heating controls, insulation etc...

air

Dardania wrote: »

Don't know if I'd agree with the second part of your statement - heating water with gas is about a third of the cost compared to electrical: of course, it presumes good heating controls, insulation etc...

While the fuel cost of gas is about one third that of electricity the end to end efficiency is much worse in summer.

All the energy used to heat the boiler, circulation loop, piping, tank, fittings and any unused hot water left in the tank goes to waste.
In summer if your incoming water is 20C & you heat the tank to 60C for showers, you'll already have a minimum 50% hit as the energy used to heat it from 20C to 40C is wasted - when the tank drops to 40C the water won't be any good for showers as it's likely to be below 35C by the time it hits you in the shower. Any energy left in water still in the tank above 40C after the shower ends is wasted also.

In winter all the above doesn't matter as much since most of the losses above will contribute to keeping the house warm anyway.

What would be great would be an electric shower with proper modulation that could take in warm water and give it just enough of a top up to make the water the perfect temperature.

Dardania

air wrote: »

While the fuel cost of gas is about one third that of electricity the end to end efficiency is much worse in summer.

All the energy used to heat the boiler, circulation loop, piping, tank, fittings and any unused hot water left in the tank goes to waste.
In summer if your incoming water is 20C & you heat the tank to 60C for showers, you'll already have a minimum 50% hit as the energy used to heat it from 20C to 40C is wasted - when the tank drops to 40C the water won't be any good for showers as it's likely to be below 35C by the time it hits you in the shower. Any energy left in water still in the tank above 40C after the shower ends is wasted also.

In winter all the above doesn't matter as much since most of the losses above will contribute to keeping the house warm anyway.

What would be great would be an electric shower with proper modulation that could take in warm water and give it just enough of a top up to make the water the perfect temperature.

Do you have a presumption of no insulation in use?

air

Dardania wrote: »

Do you have a presumption of no insulation in use?

Nope, not at all, insulation doesn't affect any of the above significantly.

air

All told it depends on your usage pattern.
If you have 2 people living in the house that take a 4 minute shower each once a day then I'd say electric is the way to go in summer.
On the other hand if you have 4 teenage girls that spend a combined total of 2 hours a day in the shower then it's time to fire up the boiler. The crossover point probably lies somewhere in between & working out exactly where it lies is likey to be non trivial.