Hello!
I'm new to the forum. Hello from downstate New York!
I had an unusual issue with a Resideo L8148E1257 AquaStat and would appreciate some input.
Tenant called with a no-heat complaint. I went over to find the L8148E1257 AquaStat circuit board burned where the 120v AC connections are. Circuit breaker on the house panel was blown and would not reset, indicating a short circuit.
My first thought was the circulator motor had shorted, burning out the board. I connected the Taco-007 pump directly to the AC supply, and it ran fine. The only other loads on the control box are a 24v gas valve, which operates normally, and a Crown 24v vent damper, which works and is original to the Crown boiler. There are no zone valves. The Crown boiler and associated parts are approx. 15 years old.
I replaced the L8148E with a new unit, and the system is running fine. My concern is that the problem will recur, since I did not find a cause.
At the shop, I opened the burned unit and tested some components. Transformer is fine and shows 28v AC at the secondary (no load) when 120v is applied to primary. Applying 24v to the relay will close it as normal. I looked carefully and did not find any wiring faults in the installation.
Pics are attached, note the damage mainly around the C1 terminal.
Would an unusual load from the circulator pump cause this type of damage? Have you heard of this happening before? Do you have any other input or suggestions?
Thank you in advance!
I'm new to the forum. Hello from downstate New York!
I had an unusual issue with a Resideo L8148E1257 AquaStat and would appreciate some input.
Tenant called with a no-heat complaint. I went over to find the L8148E1257 AquaStat circuit board burned where the 120v AC connections are. Circuit breaker on the house panel was blown and would not reset, indicating a short circuit.
My first thought was the circulator motor had shorted, burning out the board. I connected the Taco-007 pump directly to the AC supply, and it ran fine. The only other loads on the control box are a 24v gas valve, which operates normally, and a Crown 24v vent damper, which works and is original to the Crown boiler. There are no zone valves. The Crown boiler and associated parts are approx. 15 years old.
I replaced the L8148E with a new unit, and the system is running fine. My concern is that the problem will recur, since I did not find a cause.
At the shop, I opened the burned unit and tested some components. Transformer is fine and shows 28v AC at the secondary (no load) when 120v is applied to primary. Applying 24v to the relay will close it as normal. I looked carefully and did not find any wiring faults in the installation.
Pics are attached, note the damage mainly around the C1 terminal.
Would an unusual load from the circulator pump cause this type of damage? Have you heard of this happening before? Do you have any other input or suggestions?
Thank you in advance!
