Is this a dumb idea?

breaking_free

Got a new combi boiler installed last year - lovely piping hot showers...until the winter kicked in, bah humbug! 
Auntie Google tells me that this is because the incoming water is much colder than in summer; as the boiler only raises the water temp by X amount over and above the incoming temp the result is a warm shower, rather than a hot one.

More Googling has explained everything obvious (turn boiler temp to max, turn thermostatic shower mixer to max) but beyond that I don't believe anything more can be done.

So here's my dumb question: I have a very large shower enclosure so I wondered if it would be possible to fit an electric shower in there as well, which I'd only use in winter. Is this idea a non-starter?

TadleyBaggie

If the incoming water pipes are a reasonable depth underground, there isn't going to be a huge difference in temperature from summer to winter.

Regardless I would have expected a boiler to be able to cope with this, unless it is underpowered.

Apodemus

Absolutely no reason why you can't have both types of shower, with separate heads.  Of course, the electric shower will also suffer from the cold incoming water temperature in winter and give you a reduced flow at any given temperature.

silvercar

breaking_free said:

More Googling has explained everything obvious (turn boiler temp to max, turn thermostatic shower mixer to max) but beyond that I don't believe anything more can be done.

I would have thought a combination of these 2 would work. Can you get hot water out of any other tap?

ThisIsWeird

Hi b-f.

What size combi is it? Regardless of its size, tho', it's always going to be shed-load better than an electric shower - at least twoandahalf times better, likely much more. Are you considering using both at the same time (lawdie!), or just the leccy as a better alternative in winter? If the former, then blimey. If the latter, it just won't be.

So, there's most likely summat amiss.

I have a 30kW combi. It gives great showers in summer. And great showers in winter. Don't really notice a significant difference.

What's the most powerful leccy shower? 10.8kW? What's the least powerful combi? 25kW.

plumb1_2

Ya you can install a electric shower, but will look silly imo.
Dont go below a 10.5 kw, as you say the cold main temp will be lower in winter. That’s why it’s swings and roundabouts with Combi ( that’s another kettle of fish).

wont be cheap, so will have to pipe it up in chrome pipe,unless you have spare wall tiles and can sink the pipe in the wall.
And run a cable back to the consumer unit.

FreeBear

plumb1_2 said:

Ya you can install a electric shower, but will look silly imo.
Dont go below a 10.5 kw, as you say the cold main temp will be lower in winter. That’s why it’s swings and roundabouts with Combi ( that’s another kettle of fish).

wont be cheap, so will have to pipe it up in chrome pipe,unless you have spare wall tiles and can sink the pipe in the wall.
And run a cable back to the consumer unit.

If you bury the pipe in the wall, make sure to sleeve it to reduce the risk of corrosion from plaster/cement - 15mm copper is a nice fit inside 20mm conduit. And no buried joints either.

An electric shower will need to be signed off by a competent electrician to comply with Part P of the building regs - It is not a job I'd recommend someone DIYs.

Ayr_Rage

My thermostatic shower has a hidden adjustment that allows a higher maximum temperature, it is adjusted by an Allen key, I had to set mine higher to get a really hot shower.

ka7e

I have 2 electric showers and I'm sure they are both affected by incoming water temperature. Neither are warm enough on eco setting during the winter and I definitely had to turn up the dial during the recent freeze.

breaking_free

Thanks all.
It's a Worcester 32Cdi compact - apparently this is a 30 kWH boiler (and less than a year old).
I'm female and always turn the temp up on my bloke's leccy shower when I stay over (yes of course I turn it back down afterwards). I'm pretty sure women like a significantly higher temperature than most men.
The shower is hottish, but nothing like what I'm used to. Wish I could measure the actual output temp...

grumbler

As suggested above, measure the flow and the temperature in a bath tap or other tap. If it's good enough, then the problem is with the shower, not with the lack of power.