E20
Termet
Return / Flow Temperature Difference Too High
Display shows E20, furnace may run at reduced power or shut down intermittently.
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
Insufficient system flow, Closed radiator valves, Undersized or blocked piping, Faulty circulation pump on Termet unit
How to Fix / Troubleshooting
Safety: Turn off power before touching internal components; water may be hot.
- Open valves: Ensure all radiator or underfloor heating valves are open to allow adequate flow.
- Bleed air: Bleed radiators and high points in the system to remove trapped air.
- Check pump speed: If the circulation pump has adjustable speeds, set it to a higher speed according to Termet’s recommendations.
- Inspect strainers: Clean any system strainers or dirt separators that may be restricting flow.
If E20 persists, the circulation pump performance and system design should be evaluated by a heating professional.
Advertisements
Repair Difficulty
Medium
3/5
Required Part
Circulation Pump
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements