Tuesday, June 19, 2018
Honeywell V4043 - photos including microswitch
The Honeywell V4043 2-port central heating zone valve is amazingly badly documented. Honeywell don't offer an exploded diagram, nor even a line drawing of the inside of the head. I couldn't even find any reasonable-resolution images of the inside of the head, so here are my shots:
Note here that the microswitch (also called the end switch) sits a long way from the gold-coloured striker that is connected to the manual-open lever. Having taken the unit apart, I puzzled for ages about what I was doing wrong in mounting the microswitch because it looked as if it would never close. In fact, the microswitch does go in the obvious place - but while the Manual Open does open the valve (for filling and draining, Honeywell suggest) it does NOT operate the microswitch. Only electrical operation of the valve sees the striker move far enough to close the microswitch.
(If you need to replace the microswitch, it isn't offered as a standard spare for the V4043, but as noted by others, a suitably-rated Honeywell microswitch - eg V7-3E17D8 - looks like it should fit - but obviously it is up to you to check that it meets your needs)
Note that once a system is installed, operating the Manual Open lever will heat the relevant zone ONLY if there is another zone already calling for heat - or if you manually connect the call-for-heat wires (grey and orange wires) so that the boiler fires and the pump runs. Just closing the valve manually won't close the switch, so it won't call for heat by itself.
Recent V4043 valves have a head that you can remove without draining down the hot water system (some older ones do not - beware: removable ones are removed by undoing just two screws - if there are four to undo, this seems to be a sign that you have the non-removable type and if you undo all four screws, you will have water pouring out).
But how do you remove the head? Again, no help from Honeywell. Once you have undone the two retaining screws (the brass dome-headed screws shown in each picture) then it really comes down to wiggling: the head is a push fit onto copper bush on the main valve housing. From my experience, it can take a lot of wiggling.
Note here that the synchronous motor is held in place by a single screw (see second photo) - the screw hole on the motor tab that fits under the "finger" tab is NOT used.
Note here that the microswitch (also called the end switch) sits a long way from the gold-coloured striker that is connected to the manual-open lever. Having taken the unit apart, I puzzled for ages about what I was doing wrong in mounting the microswitch because it looked as if it would never close. In fact, the microswitch does go in the obvious place - but while the Manual Open does open the valve (for filling and draining, Honeywell suggest) it does NOT operate the microswitch. Only electrical operation of the valve sees the striker move far enough to close the microswitch.
(If you need to replace the microswitch, it isn't offered as a standard spare for the V4043, but as noted by others, a suitably-rated Honeywell microswitch - eg V7-3E17D8 - looks like it should fit - but obviously it is up to you to check that it meets your needs)
Note that once a system is installed, operating the Manual Open lever will heat the relevant zone ONLY if there is another zone already calling for heat - or if you manually connect the call-for-heat wires (grey and orange wires) so that the boiler fires and the pump runs. Just closing the valve manually won't close the switch, so it won't call for heat by itself.
Recent V4043 valves have a head that you can remove without draining down the hot water system (some older ones do not - beware: removable ones are removed by undoing just two screws - if there are four to undo, this seems to be a sign that you have the non-removable type and if you undo all four screws, you will have water pouring out).
But how do you remove the head? Again, no help from Honeywell. Once you have undone the two retaining screws (the brass dome-headed screws shown in each picture) then it really comes down to wiggling: the head is a push fit onto copper bush on the main valve housing. From my experience, it can take a lot of wiggling.
