Possible Problem on 2-port Motorised Valve

Help_Me_Please

Our oil central heating system has been working OK until recently. An old property which has had additional radiators and underfloor heating added over the years. One end of the house the heating is working fine, but the other end is cold including the underfloor heating. The thermostats and programmers are all turned up/on. All of the radiators have been bled. The hot water system is working fine. In the one airing cupboard there are two 2-port motorised valves and when I lock the lever to manual on the one all of the radiators and underfloor heating which were cold then comes on and work fine. Does this give you any clues to what our problem might be. Is it harmful to lock this motorised valve in the manual position?

Your advice would be most appreciated.

gas4you

Sounds like the motor has gone in the valve head.

Needs testing before replacing though.

macman

Try waggling the lever on the valve a few times to see if you can free it off so that it works in the auto setting.