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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 5648
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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I have a dunkirk pwx 5ent2 boiler. It is not getting any

Customer Question

I have a dunkirk pwx 5ent2 boiler. It is not getting any power that I can see ( no lights on and not working). What could the problem be?
Submitted: 26 days ago.
Category: HVAC
Expert:  Phil replied 26 days ago.

Hello, problem could be a tripped breaker in the breaker panel or a blown fuse (if any) in the disconnect switch,

However you might be mistaken about no power, no boiler will fire unless there is water flow though the boiler, flow switches are fit for that purpose, look for a flow switch in the boiler piping near the boiler, and insure that the pump is running

If the pump is running and the flow switch is not tripped then the system could be vapor locked due to air trapped in the radiators etc,

Look all that over, let me know, we can go from there,

Customer: replied 26 days ago.
The pump is not running. I don't see any breakers popped
Expert:  Phil replied 26 days ago.

thanks, turn all the thermostats in the house up to 90F and tell me if the pump runs or not, if not, look for an off switch at the pump,

Look for a 12 x 14 or 16" box on the boiler room wall, marked Taco Relay or some such, it will have wires running to each thermostat and to the boiler and the pump. This can get quite involved, tell me a lot about your technical skill sets so that I can coach you most effectively.

Customer: replied 26 days ago.
Pump not running. I am an aircraft mechanic.
Customer: replied 26 days ago.
Can you send instructions to my email***@******.***? I have to work in the morning and have to wake up early.
Expert:  Phil replied 25 days ago.

Hello again, virtually all of these systems are different from one another, there is no telling which design strategy was used in laying out the system.

Thus, no standard set of trouble shooting instructions other than the following very general advice:

1 Trace the power supply to the pump back to its source switch or relay.. if you are lucky it will be simply turned off, if however the power source goes to a relay box and a relay with a printed circuit card inside, extensive and complex trouble shooting will be required and that will vary with the brand, model number and type of relay or zone controller.

as mentioned earlier make sure that all of the zone thermostats are set to heating and 90F (for testing only).

Meantime I will opt out so that other experts here can see your situation and respond.

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