suitable shower to use with combi boiler?

skintpaul

Old shower unit wore out, which was fed from (on same floor) hot water tank..

water piping to where the shower was still remains, isolation valves on hot and cold feed- also the wiring, leading away to a fused switch.

Not sure what is still connected, as we have since had a combi boiler fitted in kitchen, also on same floor.

As I am rather tall, wondering what unit is suitable to give the hot water feed an extra boost, to about 8 feet high.

MX5huggy

You can't easily boost water from a combi, but you probably don't need to. The combi supplies mains pressure hot water this will provide a good shower even for a few tall person.

The limiting factor for how good (if a good shower is one with lots of water) the shower is the power of the combi.

skintpaul

pressure gauge about 1.5 bar ? Not sure what the old boiler was like, but shower flow was rather feeble!

benjus

The hot water pressure will depend on 2 things - the pressure of the water coming in, and the power of the combi - i.e. can it heat the water up as fast as it comes in, or does it need to slow it down?

You'll want a thermostatic shower for use with a combi to smooth over any temperature fluctuations.

C_Mababejive

skintpaul wrote: »

pressure gauge about 1.5 bar ? Not sure what the old boiler was like, but shower flow was rather feeble!

The gauge isnt showing supply water pressure,its showing system pressure so for the purposes of your question, it isnt relevant.

MX5huggy

Your old shower only used the height difference between the cold water tank (likley in the loft) and the shower head to push hot water.

Time how long it takes to fill a bucket from a hot tap work it out in litres per minute 7 is ok 9 good and 11 excellent. But ofcourse the higher the rate the higher the running cost.

lstar337

What power rating is your combi?

We have a combi on the same floor as our thermostatic mixer shower and it has plenty of power! At full pace it is enough to hurt your scalp.

I think you are comparing wildly different technologies and worrying over nothing.

A thermostatic mixer is the best you can use with a combi anyway, so just get one.

Lungboy

I had no idea about not having a power shower with a combi boiler, my mum has 2 power showers, one only about a year old, and nobody ever mentioned the fact that as she's got a combi with no storage tank she shouldn't have a power shower.

macman

If by 'power shower' you mean a conventional shower fitted with a booster pump, then no, you can't run that off a combi, as power showers must be tank fed.
If you mean an electric shower, then that's fine as they are fed from the rising main.

Lungboy

Oh, didn't now there was a difference, we've always called them power showers. One is an ancient Mira Sport, the other is a new Mira Advance (I think).

benjus

Lungboy wrote: »

Oh, didn't now there was a difference, we've always called them power showers. One is an ancient Mira Sport, the other is a new Mira Advance (I think).

Those two models are instantaneous electric showers - they take a cold (mains) water supply only and heat it up using electricity. Generally they are not powerful enough to heat mains water to a comfortable showering temperature at the rate the water comes in, so they have to reduce the pressure.

Power showers take both hot and cold water from tanks and pump them at high pressure through a mixer to create a comfortable temperature at a good pressure. You need a pretty big tank though, as the pump can drain a small tank quite fast. This is why you can't use them with a combi boiler - the combi boiler can only produce hot water at a fixed rate, and no amount of pumping will increase that.