Er6
Heatit Internal Relay/Triac Failure

Display shows Er6 and thermostat cannot switch heating on even though demand is present

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

Worn or welded relay contacts, Failed triac on PCB, Damage from overcurrent or short circuit, Manufacturing defect in power stage

How to Fix / Troubleshooting

Safety first: Turn OFF power at the breaker. Do not attempt to repair the internal electronics; they are not user-serviceable.

Steps to troubleshoot:

  • 1. Confirm load and wiring:
    • Verify that the load (floor heating, panel heater) is correctly wired to the thermostat's load terminals.
    • Check that the load itself works by temporarily connecting it directly to mains (only by a qualified electrician).
  • 2. Check thermostat output:
    • With power ON and a heat demand present, measure voltage at the load terminals.
    • If there is no output and Er6 is displayed, the internal switching device is faulty.
  • 3. Replace thermostat:
    • Remove the faulty thermostat and install a new Heatit smart thermostat of the same rating.
    • Ensure the connected load does not exceed the new thermostat's maximum current rating.
Advertisements

Repair Difficulty

Hard 4/5

Required Part

Heatit Thermostat Power Module / Relay-Triac Assembly
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements