Aquastat wiring

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Vtech23

New Member
Feb 7, 2020
2
Iowa
Hey there. I have recently bought a northwoods boiler that I have built a little shed and put outside the house. The problem I am having is I can get the stove to run up to temp and shut off but when the thermostat calls for heat my pump will not kick on. I have been researching everything I can about different wiring but I think my aquastat is different from every other one I see. Could somebody help me identify what honeywell model my aquastat may be. I only seen a #125017aaa on the side but nothing I search turns that up. Any ideas?
 

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Are you running a 2 or 3 wire thermostat? I seem to recall an issue on older oil burners that originally had 3 wire stats but then a 2 wire was installed.
 
Basically all Stats are just relays and can be tested for continuity. Just have to figure out whether there normally closed or open and test accordingly. Once you confirm that the stat is telling the device what to do then you can start troubleshooting that. Just a wild guess but if the stat is sending a proper signal I'd start checking pump capacitors and starters.
 
I currently has a 2 wire thermostat. If I wire the pump straight to my power it will run so the pump is good. I am wondering if I hook a thermostat wire to the screw for the vavle on the relay/transformer and run a 3 wire set up if that will work. I took a few picture of the relay and the schematic it has on the bottom for a reference.
 

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Is the thermostat closing properly. If the two terminals are jumped the pump should start. Otherwise the relay maybe bad
 
What model of thermostat is it. I'm no boiler guy but the schematic shows what should happen when the thermostat calls for heat
1: no call, the stat should be open with no continuity between the wires
2: call for heat, the stat closes, there should be continuity.
3. When T1 and T2. Are closed the valve should actuate and open and the relay should close sending power to the pump.

Again, not a boiler guy, but it would make sense that the aquastat should tell the boiler what to do and the thermostat should tell the pump what to do.