Warning: Your Navien boiler has detected a blockage in the condensate drain line. This could lead to water damage if not addressed promptly.
How to Fix Navien Code E594
Locate the condensate drain line and follow it to the exit point, usually a floor drain or outside
Check for any obvious blockages or kinks in the line
If you find a blockage, try to clear it using a wet/dry vacuum or a plumber's snake. If you're unsure, contact a professional
How to Reset Navien Code E594
Turn off the unit using the power button on the front panel.
Turn off the gas supply valve.
Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
Restore power at the breaker, then open the gas valve.
Turn the unit back on. If the error returns, the underlying issue needs repair.
What does E594 mean?
The E594 error on your Navien boiler indicates that the condensate drain line is blocked. Condensate is the byproduct of combustion, and it needs to be safely removed. When the drain line is blocked, water can back up and potentially cause damage to your boiler and surrounding areas. It's important to address this issue as soon as possible to prevent any further problems.
This error occurs when the main controller does not operate properly. ● Turn off the furnace, turn it on again, and check if the furnace is operating properly. ● If this error occurs continuously, contact Technical Support at 1-800-519-8794.