CTC Stuck Fan Relay / Post-Purge Malfunction

CTC water heater fan runs continuously even when no hot water is being used (gas models)

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

Stuck relay on main control PCB, Faulty fan speed feedback, Control logic error, Shorted wiring to blower

Safety first: Turn off power and gas before inspecting the blower circuit.

Steps to check:

Allow several minutes after hot water use; some post-purge is normal. If the fan never stops, proceed.
Inspect blower wiring for shorts or miswiring.
Check the main control PCB for signs of overheating near the blower relay.
If the blower stops when the control board connector is unplugged, the relay is likely stuck and the main control PCB should be replaced.

Hard 4/5

Main Control PCB

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