Replacement Synchronous Motor for motorised valves ACL Honeywell Landis Gye Satchwell Sopec Tower DIY Replacement 2-Port 3-Port Valve Failure

Product Information

When using two 2-port valves, the control system may be known as a Sundial S Plan system or a Honeywell S Plan system. If the motor cap says “Synchronous” rather than “SYNCHRON ®” it may cost less than half but you’ll probably be changing it again before long! A normally-closed valve is closed when no power is being applied to it and needs electrical power to drive it open.

So, if you set the system for Heating Only (Hot Water must be off or satisfied on the cylinder stat) the valve motor drives the valve to close port B while it leaves the heating port A open. If it has seized up you may be able to free it temporarily by gently moving it backwards and forwards but it will probably seize up again before long. i guessed it was me putting the valve into manual but it wasnt working again this morning and the same process didnt get me anywhere.

The grey wire is used to drive the valve to the Water Off position, in which only the heating port A is open; it closes port B. When using a 3-port valve, the control system may be known as a Sundial Y Plan system or a Honeywell Y Plan system.

Only one replacement motor (40002737-003) is required for all modern motorised valves irrespective of body size, pipe connection type or whether 2 or 3 ports. Old Satchwell Sunvic valve bodies used to turn through a full circle, as did Switchmaster Midi valve bodies. The valve won’t be driven open and the end switch will not be made (connected) so power will not be sent on to the boiler or pump.Cookies are small text files placed on your device that remember your preferences and some details of your visit.