E9
Protherm
System Capacity / Addressing Error
E9 error and thermostat indicates that maximum number of devices or zones has been exceeded.
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
Too many zones configured, Duplicate addresses on bus devices, Firmware limit reached for connected devices
How to Fix / Troubleshooting
Safety: Power down bus devices before changing addressing switches.
- Step 1 – Review system design:
- Check Protherm documentation for maximum supported zones and devices.
- Step 2 – Remove unused devices:
- Delete unused zones or devices from the thermostat configuration.
- Step 3 – Check addresses:
- Ensure each zone module or bus device has a unique address (via DIP switches or software).
- Step 4 – Reboot system:
- Power cycle all bus devices and the thermostat.
- Step 5 – If E9 persists:
- Consider upgrading to a Protherm controller that supports more zones or simplifying the system layout.
Advertisements
Repair Difficulty
Medium
3/5
Required Part
Protherm Zone Control Modules / Bus Devices
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements