After setting water temp for shower if any one turns on cold water or flushes Instant scalding water comes from tap. Local plumbers have problem finding solution to problem. Just bought this house about a year ago
Could you advise us what equipment you have there to supply your hot tap water.
Do you have an instant hot water heater hung on the wall, a stand-alone (gas-fired, oil-fired, electric) HW heater; or is there a tankless HW heater connected to a boiler, or an indirect tank connected to the boiler, etc.
There are also more recent "combi" boilers in some houses that combine the HW supply & heating system into one boiler.