Shower turns on automatically and banging sounds All aspects of plumbing questions and answers, help, tips and information

[szd55pilot@gmail.com]

Hi, Hoping I can get some help here cos the landlord isn't forthcoming with any. There are some symptoms, here is the layout, modern combi-boiler on ground floor, Triton bar mixer shower over bath on 1st floor in bathroom, also bath and sink.
1. When we use the sink in the bathroom, the shower over the bath, turns on and there is a loud banging sound. The shower 'volume' knob is fully off. The 'temp' knob is at coldest position. To get the sound to stop and the shower to stop I have to turn on the bath or sink cold tap.
2. The shower is never warm enough to use. The boiler water temp is set at 57 deg. The shower internal temp valve is set to fully hot. The water flow is fine, it's only barely luke warm. The bath side is glued in place so I can't get to the pipework easily.
3. If we use some downstairs taps, the shower comes on upstairs and the banging starts again.
4. Sometimes at night the shower turns on and the banging all starts without anything else happening in the house.

Please advise what might be causing this and how I should tackle it.

Huge thanks to anyone who can help because it's driving me mad getting up at 5am to stop the noise :-)

[stoneyboy]

Hi szd55pilot,
Have you checked your mains pressure and the maximum operating pressure for the Triton valve. I suspect you are on mains direct for cold and a reduced pressure for hot via the combi.
Regards S

[stoneyboy]

Hi szd55pilot,
Have you checked your mains pressure and the maximum operating pressure for the Triton valve. I suspect you are on mains direct for cold and a reduced pressure for hot via the combi. Your valve does need balanced pressures.
Regards S

[szd55pilot@gmail.com]

All I know is that the cold water pressure is high. Also the bath/sink hot tap appears to be either on or off. There is almost no adjustment in between. I checked the water stop cock and it's fully on. I have zero plumbing experience.

[stoneyboy]

Hi szd55pilot.
Suggest you get a pressure regulator fitted in your mains in pipe (not a flow regulator). Pick one that is adjustable and has a pressure gauge you will then be able to balance your hot and cold supplies. It should be fitted in the mains in pipe close to your mains stopcock.
Regards S

[szd55pilot@gmail.com]

Thanks, I'll investigate, however I think this would need to be the landlord.
If anyone else has any further suggestions, please shout, we are desperate and still no response from the landlord.