E14

EHC Communication Fault (PCB to Controls)

Boiler displays E14, no response to thermostat or programmer, or erratic operation.

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.

Possible Causes

Faulty room thermostat or programmer, Broken low-voltage control wiring, Incorrect wiring at terminal block, PCB communication failure

How to Fix / Troubleshooting

Safety: Isolate power before accessing wiring terminals.

User checks:

Confirm the room thermostat has power (batteries or mains) and is set above room temperature.
Check programmer or timer is set to an ON period and not in holiday mode.

Engineer checks:

Verify correct wiring of the EHC boiler control terminals according to the installation manual.
Test continuity of thermostat and control cables; repair any breaks or shorts.
Temporarily link the boiler’s call-for-heat terminals to see if the boiler responds; if it does, the external controls are at fault.
If the boiler still shows E14 with a direct link, suspect the PCB and replace if necessary.

Always label and document wiring before making changes to avoid misconnection.

Repair Difficulty

Medium 3/5

Required Part

Room Thermostat / Programmer

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