E20
Alpha
Safety Chain / Limit Circuit Open
Display shows E20; unit may not start or may shut down unexpectedly.
Advertisements
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Advertisements
Possible Causes
Open high-limit thermostat, Tripped rollout switch, Loose safety wiring connection, Faulty safety device
How to Fix / Troubleshooting
Safety: Turn OFF power and gas. Do not bypass any safety devices.
- Locate safety chain: Identify the series of safety devices (high limit, rollout switch, flue limit) wired back to the Alpha control board.
- Check for manual reset: Some rollout or high-limit switches have a manual reset button. If tripped, press to reset once. If it trips again, stop and investigate the cause.
- Inspect wiring: Look for loose spade connectors, broken wires, or signs of overheating around safety devices.
- Investigate cause: A tripped rollout or high limit often indicates blocked burners, venting issues, or overfiring. Have a technician correct the underlying problem.
Never operate the heater with any safety device bypassed or jumpered.
Advertisements
Repair Difficulty
Professional Required
5/5
Required Part
High Limit Thermostat
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements