Mixer Shower from 22mm Bath Pipes

Hi

I am thinking about installing a mix shower from the 22mm pipe that feeds the bath taps. By Teeing off before the tap up the wall and then reduce the 22mm to 15mm.

Is this ok to do and will it be enough pressure for the mixer shower?

Thanks in advance.

Please give details of your hot and cold system. Are they both from a tank or do you have a combi boiler or some other system ?
A traditional boiler would have a hot water cylinder etc

Hi dal5band, Thanks for the quick response.

We have a this Potterton Boiler, as well as an immersion heater in the bathroom cupboard and cold water storage and central heating (smaller) tank in the loft. The pipes under the bath come straight off the boiler (i believe) which is in the kitchen below bathroom.

Hope this helps, let me know your thoughts.

Cheers

1. You have a vented hot water system.
2. It is likely that the bath is fed from the cold water storage cistern (CWSC) in loft.
3. Very unlikely the cold or hot are direct from the boiler. It is not a combi boiler.
4. The arrangement you are seeking to implement is likely to give very disappointing results. The hot and cold pressure is likely to be of the order of 0.1 bar, which is very low. This pressure is given by the vertical distance between the bottom of the CWSC and the shower head.
5. I would suggest your options are:
5.1 Move to an unvented hot water system. Expensive - around £1,500 for the cylinder, and the same again for fitting. Needs minimum incoming dynamic water pressure (approx 2.0 bar) and flow rates (approx. 20 lpm). NOT a DIY proposition as must be installed by G3 registered engineer. Needs local Building Control niotification and cylinder should have annual service.
5.2 Install a shower pump. Around £400 for a decent pump. Installation £300+ depending on pipework and access.
5.3 Install a power shower. £200 to £300 for the shower. Installation £250+. Shower adequate but not outstanding.
5.4 Install a combi boiler. Probably around the same cost as an unvented hot water system. Perhaps worth considering given the age of your existing boiler. Minimum incoming cold pressure and dynamic flow rates required. Around 1.5 bar pressure and 15 litres / minute.

or you could just fit a low pressure shower they give good results on .2 of a bar plenty of UK properties have over bath or combined tap and showers, not exactly the best shower but it does a job.

You can easily test the pressure by indirectly measuring the flow rate, grab a bucket , mark a line at ten litres and time how long it takes to fill. 10-seconds 3bar, 10-20 second 2 bar, 20 seconds plus 1 bar and lower dependant on the time taken. Then see if a shower is out there with your working pressure written on it.

You could just bang in the shower and then if its not up to spec add a booster, I like Stuart turner pumps, but then again I would.