Low hot water pressure in mixer shower

[Joleen Hall]

Hi all, I'm brand new to this so I apologise in advance if I'm asking a question that has already been asked, but looking through similar posts, my question does not appear to be answered.

Ok, so, we recently had a new bathroom installed. We have a combi boiler that we had installed 2 years ago when we moved in. Our new shower is a Triton Benito Bar Mixer Shower. The pressure is brilliant for the cold water, but when we try to use the hot water (combined with the cold), the pressure reduces massively and you are left with very low pressure.

We have a shower head fitted to our bath taps and the pressure on that is amazing, so I don't think it is an issue anywhere other than the new shower.

We have checked the boiler and the pressure gauge is between 1.5 and 2, which I believe is where it should be.

I have checked online and cannot seem to find an answer. Our plumber is ghosting us at the minute and when we did get him to come and have a look, he said it was just the way it was?????

 

[Kiaora oap]

Hi
It may help if you check a couple of things,
Reference the basin, or bath taps,
Run the cold tap and calculate the “flow rate” (not pressure)
And then the hot tap, flow rate,

to calculate the flow rate, get a jug, with 1lt mark, run the tap, and using a stop watch ,
how long to fill to 1lt mark,
Ie 5 seconds = 12 lpm

this will tell you the performance of the hot and cold supplies, if they both say, over 9/10 lpm I could be the shower faulty, if it’s thermostatic, they have fail safe to avoid getting scolded

good luck

 

[Hausfix]

If you can isolate the water supply to both the hot and cold feeds to the shower, try unscrewing the large silver nuts that connect the bar mixer to the pipes that supply it. It’s possible that there is a rubber washer there with a dome shaped mesh filter. This filter may be clogged with debris from the installation and causing a blockage on the hot supply or even the cold supply (which will make the thermostatic valve restrict the overall supply to keep the water at a safe temperature)