The Honeywell V4043 series of two port Motorised Valves has a wide range of flow control applications in domestic and light commercial central heating systems.
 
The V4043H normally closed models have end switches forelectrical control of pump and/or boiler. The V4043B normally open model is particularly applicable to control of solid fuel systems, since it will always fail-safe in the event of a power failure.
 
Motor open
Spring return action
Manual lever for filling & draining the system
Powerhead replaceable without draining down
Potential free end switch for electrical control of pump and/or boiler
Quiet operation, minimal power consumption