Skip to main content

Ready to hire?

Post your job in minutes, browse real reviews and choose who to speak to.Post a job

Need some tips or advice?

Ask a question
Plumbing

Increasing shower pressure: hot water from combo boiler, cold from loft tank

Anonymous user 09/03/2024 - 2.33 PM

The current setup I have in my bathroom is: hot water coming from a combo boiler supplied from the mains; cold water coming from a tank in the loft (about 1m higher than the shower head). The shower is then one where there's a dial to set the temperature and a valve system behind to mix the two water feeds. Because of this setup, the pressure from the hot water feed is higher than that from the cold water. So, to get the shower working properly (it pulses on and off otherwise) I need to have a hot tap slightly open at the same time as having a shower (thereby reducing the hot water pressure to a similar level to the cold). This makes the shower work, but at a fairly low overall pressure. I'm interested in any recommendations people have for how to increase my shower pressure. What I've thought of are: 1. Bypass the cold water tank altogether by directly connecting the in-out feeds, thereby effectively having 2 separate mains pressure cold water feeds for the property. Concerns in doing this are: all the pipework from the tank onwards is used to low pressure, then suddenly getting mains pressure it may start leaking; that cold water feed also goes to my washing machine and toilet - both of which have low pressure fittings that would need replacing. 2. Extend the current mains cold water feed on to the shower, leaving the remainder of the water-tank feed in place (to the toilet, sink and washing machine). Downside to this is it will need quite a bit of tiled flooring being removed in order to get access. Are there any things I'm overlooking? Is there some kind of power shower I can buy that would work with this combination of hot from combo boiler and cold from a tank? Is there a way of locally boosting the pressure from the water tank? Any suggestions would be very welcome.

Are you a tradesperson and able to answer this question?

Log in

4 Answers

Anonymous user

As you suggested just takes the mains feed for the cold. Either that or fit a pressure equalising valve.
Answered2 September 2015
2

Anonymous user

Usually a bathroom cold supply is fed from a header tank and the hot supply comes from the hot water storage tank. When a combi boiler is fitted the hot water tank and the cold water header tank become redundant and are removed. If you have a combi boiler you shouldn’t have a cold water header tank? The solution is to find the mains cold water feed to your header tank and connect this directly to the outflow cold supply from this tank thus bypassing the tank. You can then remove the tank and create loft space as well as increasing cold supplies to mains pressure. For safety you can at this joint fit a pressure reducing valve. Regards Gareth
Answered8 January 2026
1

PDunn

Rating: 5 out of 5
Holloway, London
Decommission the cwsc by turning off the cold feed. Drain down. (Leave or remove Tank) Connect mains cold feed to gravity tank fed outlet/s Turn on mains to replenish all cold feed outlets to equalise balance hot and cold feeds on your combi System... And don't go down a power shower route.?!?!!?? Pd
Answered14 March 2019
0

Nicholas & George builders ltd

Rating: 5 out of 5
Northampton
Just reject the tank , from the time you have a combi boiler no longer needed. Make a connection 2 pipes the inlet to the tank to outlet and job done
Answered16 December 2023
0