I have a fully pumped gas CH system with Horstmann Centaur Plus C27 programmer and Honeywell V43073A1088 motorised valve.
When HW or CH are on separately each work fine, and motorised valve (with cover off) can be observed moving from one side to the other accordingly as Boost/Advance are pressed, or programmer kicks in.
Problem arises when 2 are operated together, as follows:
If Boost and Advance are pressed simultaneously, valve moves to mid position, and both HW and CH work. However, if Boost is pressed when Advance is already activated (or programmer is programmed for HW to come on after CH) valve doesn't move from CH side and we get no hot water.
In all above cases tank stat and thermostat are switched up high, but both work correctly.
Any thoughts? Is this a wiring problem or motorised valve problem, or is there a simple test?
Many thanks for any ideas!
When HW or CH are on separately each work fine, and motorised valve (with cover off) can be observed moving from one side to the other accordingly as Boost/Advance are pressed, or programmer kicks in.
Problem arises when 2 are operated together, as follows:
If Boost and Advance are pressed simultaneously, valve moves to mid position, and both HW and CH work. However, if Boost is pressed when Advance is already activated (or programmer is programmed for HW to come on after CH) valve doesn't move from CH side and we get no hot water.
In all above cases tank stat and thermostat are switched up high, but both work correctly.
Any thoughts? Is this a wiring problem or motorised valve problem, or is there a simple test?
Many thanks for any ideas!