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Heating  Heating

Brand

Lochinvar Lochinvar List all brands

Type:

Cadet CDN040 view Cadet CDN040 List all types

Error code:

b04
List all errors


Error code: b04

Cause of error code b04

The temperature rise across the heat exchanger has exceeded 60°F.

Solution for error code b04

- Verify that the system is full of water and that all air has been properly purged from the system.


- Verify that the boiler is piped properly into the heating system.


- Check for 120 vac to the boiler pump motor on a call for heat. If voltage is not present, check the wiring back to the main control board. Replace the main control board if necessary.


- If 120 vac is present on a call for heat and the boiler pump is not operating, replace the pump.


- Verify that the boiler pump is set to the proper speed or that the pump is the proper size.


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