Morning all, Had a new boiler installed last week, finally have hot water everywhere and more pressure through the hot taps. Previous to this the shower always had low hot water pressure and often went cold. We have the same problem with the new boiler. I'm assuming it must be the shower valve not putting enough load on the boiler for it to think it needs to supply hot water all the time? Also had the shower valve replaced in a previous property and that sorted both issues. Cheers, Paul.
I'd thought about this, but the cold water has no pressure issues. I'll remove later after work to check. Horizontal type like this https://www.screwfix.com/p/cooke-le...ostatic-mixer-shower-valve-fixed-chrome/117fv
I assume you have a combi boiler ? If the shower head is restricting flow the boiler may not fire up. There are also filters at the shower valve inlets that may need cleaning .
Sorry for the delay, yes it's a new Worcester Bosch. When the hot water comes through it's hot as it should be but keeps turning off and going cold. It doesn't do this on the taps so I'm assuming it's got a blockage. I've contacted the plumber I usually use so will get sorted. The house is old and we've already discovered quarter turn valves that have stopped working and had to be replaced.
Just an update on this. It turned out that there was an ancient thermostatic valve on the hot water feed from the boiler to the shower. Apparently they're quite often fitted for pensioners for baths etc and believe the hot water may have originally been to a tap. That was the cause of the temperature going hold and hot, the low water pressure and the awful noise. Now we have a lovely hot shower with good pressure.