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Heating  Heating

Brand

U.S.Boiler Company U.S.Boiler Company List all brands

Type:

MPO-IQ147 view MPO-IQ147 List all types

Error code:

ErP91
List all errors


Error code: ErP91

Cause of error code ErP91

Communication Error


 

Solution for error code ErP91

Communications error has been detected.
Remove all devices from the Enviracom connections, 3-pin plug and screw terminals "1-2-3".    
If the error does not clear within one minute, measure the voltage on terminals "2" and "3".    
If the voltage across terminals "2" and "3" is between 20VAC and 30VAC, replace control.    
If it is outside of that range, review boiler wiring.  There should be approximately 24VAC across "2" and "3".


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