burnt transformer in aquastat relay

Empire_2

There has to be something causing the slow burn of the t-former, I'm sure all will agree on that. Since you had everything under the Full load, I am at a loss, but did you check for any grounded circuits on the stat wires? I am searching for answers, but sounds like everything should be on line and fine. Any vent dampers, etc..? Just trying to get to the bottom of this nascence.....

Mike T.

jim armstrong_2

burnt transformer in aquastat relay

I have just replaced an aqua stat relay on a slant fin boiler. The transformer in the aqua stat went out a few hours later. Could a bad circulator pump be the cause. The aqua stat relay that I replaced was only a couple of months old.

Empire_2

Hi Jim

I would look more towards a lo voltage short. Possible grounded line somewhere. If you have a clamp on amp probe, check the circuit that actuates the boiler. Anything above 3 would be reason for concern. Remove wires and jump out the circuit and also see what your new reading is.

Mike T.

jim armstrong_2

burnt transformer in aquastat relay

Thanks for the reply Mike.
I will be going back to the job site this morning and will check. The only low voltage wiring on the boiler is the thermostat connection and the gas valve. The stat is connected to T and TV terminals and the gas valve to B1 and B2 terminals. The aqua stat relay is a Honeywell L8148E 1265.

Empire_2

Yea like I said

I would at least get the new Augastat in and eliminate the stat, jump it out and see what you get. Check the amp reading on the GV while your at it. Usually shorts like the 1 you describe are actually grounded circuits and draw just above what is normal. Smokes controls down the road is usually the result.

Mike T.

jim armstrong_2

burnt transformer in aquastat relay

I put my amp meter on everything. Under full load the transformer reads .27, the circ. pump reads .75, the gas valve reads .21, the jumper read .15 and the thermostat read .17 . The total load on the power source read .81

jim armstrong_2

burnt transformer in aquastat relay

Hi Mike,
I did check stat wires for grounding and did not discover any. I may be grasping at straws here but is it possible that the ambient temperature around the transformer is getting to high and causing this. The reason I ask is that the Honeywell emblem on the cover of the relay most recently changed was deformed, melted, but both decals were intact inside. I don't know if the previous was or not.

Empire_2

That's hot is discoloration happens....

It his from boiler, meaning the heat from it or is this a voltage problem? Something is creating the excess heat and has to be corrected. It's kind of hard to help is I cannot see what you have.

Mike T.

jim armstrong_2