3 Port Valve question/central heating problem

[jlyall]

Hi all,

I've got an intermittent problem with my heating thats driving me crazy. It can work perfectly for days, and then I'll get no heating. In order to get it going again I turn off the power to the central heating for literally 5 seconds, and I can hear the 3 port valve wind back under the spring, then all works again perfectly. I've checked the wiring so many times and it all seems correct to the y plan diagram.

I've got a worcester bosch greenstar 25i system boiler, nest thermostat, y plan with a hot water tank thermostat.

Any help would be really appriciated!

 

[HERTS P&D]

Have you thought you might have a dirty system where the 3 port valve is getting stuck?

Do you have a magnetic filter on your system?

Andy

 

[jlyall]

That could be possible I guess. I haven't checked the water in the system tbh, but why would turning off the electric reset everything? Could it be possible that when a combination of h/w on and/or c/h on is causing the valve to move to its furthest position and its not moving back except when the power is turned off, and there is no power on the orange wire?