I have a Vaillant hot water boiler (GA92-100 MV) w/ 2 zones that I am having some issues with. The other day we had some family over and one of them turned off the emergency switch for the boiler at the top of the stairs, we didn't notice it until the next morning when it was very cold so I turned the switch back on went downstairs and the boiler was working. It worked for maybe half an hour and then turned off and will not come back on. The pilot light is a continuous pilot light that does not go out and it's working, there's 120 volts coming into the control board and there's also 120 volts going out to the circulation pump. Both of the zones have 24 to 26 volts in that range going to them and both of the thermostats are commanding the two zone valves to turn on but on the two wires coming from the zone valves into the control board which would usually be about a 24 volt signal there's nothing, so I figured maybe there's an issue in the wiring and I wired up a new wire from the zone valves back down to the control board. It had 24 volts coming in for maybe 10 15 seconds and then dropped out and no longer gets 24 volts.
So I think there may be an issue there but I'm not 100%. I have not worked on furnaces before any help would be appreciated as it is a little cold out. I'm pretty handy electronically and don't have any issues testing the system
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