We often see where these cause problems with combi boilers when they fail due to check valve (if installed) failure or thermostat failure where cross over from cold to hot may occur.
If they are installed with check valves and the hot check valve fails or gets some crap under its seat then the thermostat must also have failed or again have something stopping it from closing off the hot port??.
I havn't got a thermostatic shower so in a correctly working thermostatic shower if the temperature control is turned to fully cold does the
combi boiler stay off??.
Below is a sectioned thermostatic valve which doesn't look quite right to me as there is no clearance(s) between either the cold inlet at the top of the shuttle and the hot inlet at the bottom of the shuttle.
Also a photo of a TMV shuttle (plastic piston) that i found lying around somewhere.
If they are installed with check valves and the hot check valve fails or gets some crap under its seat then the thermostat must also have failed or again have something stopping it from closing off the hot port??.
I havn't got a thermostatic shower so in a correctly working thermostatic shower if the temperature control is turned to fully cold does the
combi boiler stay off??.
Below is a sectioned thermostatic valve which doesn't look quite right to me as there is no clearance(s) between either the cold inlet at the top of the shuttle and the hot inlet at the bottom of the shuttle.
Also a photo of a TMV shuttle (plastic piston) that i found lying around somewhere.
