Water pressure problem - cause?

[gurgleenglish]

Hello, I just bought a period property.

There is one bathroom with a shower. The hot water and radiators run off gas, from a condensing boiler (which has a hot water tank).

when showering the pressure is super good when I turn it cold, but it drops massively when I turn it hot. I feel like I’m fighting with it to get a good even/balanced temperature for a shower.

I don’t know why the pressure drops like this on hot. It’s either cold or hot shower and takes a lot of fiddling to get it right.

any thoughts? :(

Hello , thanks for responding

it’s gas powered hot water and heating, not electric. It’s not an electric shower.

the tank is old fashioned cylinder. Definitely not a modern one.

it’s not pressurised at all.

Might it be an air lock? That happens very occasionally with my shower. I turn the shower on, lift the hose off the hook and lay it on the shower tray. It runs at a slow rate for a min or so then the air lock blasts out with such force the shower head spins round and blasts water everywhere. It’s usually fine then for several more months. Might be worth a try🤞

What are your flow rates like out the taps when you run them at max speed ?

I suspect you have a high pressure differential between the hot and cold.

There are a few things that might help.If you can raise the water temperature of the hot side, then you will need more cold water added to the mix in order to cool it down to the same temperature. This will improve the flow rate.

If you have good hot water flow out of the taps, it could be that your hot water input on the mixer shower has a filter which has become blocked. Time for a clean.

Everything else you are probably looking at some sort of pump or pressuried system which is expensive. Maybe you can replace the shower with an electric one, but it will be pricey per shower compared with gas.