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Jumper wire in Vent Damper receptacle on Laars mini-therm JVT75N boiler

asher Member Posts: 2
Hi, I was wondering if someone could help me please.

I have a Teledyne Laars mini-therm JVT75N boiler and the jumper wire in the power venter/Vent Damper receptacle got accidentally pulled out. I put it back according to diagram A in the installation document C1056A however I have now realized that my receptacle is actually turned 180 degrees from the picture. This means that I actually put the jumper wire between the Y and O wires in the receptacle! See Figure 9c on page 12 of this document for wiring diagram

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When I turned the boiler back on and the thermostat turned on there was loud clicking noises every 0.5 seconds. I quickly turned the boiler off and eventually found a wiring diagram that showed my mistake i.e I had put the jumper wire in wrong. I have now managed to put the jumper wire where it should be but now when the thermostat turns on I can see the zone valve open very slowly but the boiler does not come on.

Is it possible for you to predict from the wiring diagram what I might have damaged by putting the jumper wire wrong? Have I damaged the zone valves or the zone pump relay?

I think the loud clicking noise is the same as when the thermostat usually turns on but I am not sure if that noise normally comes from the zone valve itself or the zone pump relay?

Many thanks for any help you can provide.



  • asher
    asher Member Posts: 2
    Issue resolved

    Sorry, I got a bit over paranoid about my issue and wasn't thinking straight. Checked the boiler fuse and it was blown. Replaced it and everything is working fine.
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