There are 2 showers in the house. When the 1st floor shower is turned on, the water first runs warm but then cools off after about a minute or less. On the ground floor however, both the kitchen tap and the shower give hot water normally and there is no problem, so Im thinking it can’t be a central heating boiler issue. Could the upstairs shower be faulty and if so, what could be wrong with it? Thanks
an insufficient supply of hot water, sediment build-up in the water heater, or a broken dip tube.
Given that the issue is solely associated with one shower alone it’s highly likely to be an issue with the shower valve itself rather than your plumbing system.
Possible issues could be a faulty cartridge, faulty non return valves etc.
To truly know what the issue could be, you’d need to have a plumber attend to inspect the existing cartridge, attempt to repair or source a replacement part.
Pressure problem with the shower
If your shower turns cold after a few minutes, it could be due to an insufficient supply of hot water, sediment build-up in the water heater, or a broken dip tube. Address these issues by cleaning the water heater, checking the hot water supply, and replacing the dip tube if required
Yes, it could be a defective tap, it doesn't mix well.
A lower pressure could give such results in general if both showers are used simultaneously. If only the upstairs shower is used, it could have a faulty thermostat.