Parts & Repair
Combi Boiler Control Board (PCB) Replacement
The printed circuit board is the brain of your combi boiler. When it fails, the symptoms can look like almost anything — accurate diagnosis matters.
The control board — also called the PCB (printed circuit board) — coordinates everything your combi boiler does: ignition, the gas valve, the pump, the fan, temperature sensors and safety lockouts. Because it touches every function, a failing board can produce confusing, intermittent symptoms that mimic other faults, which is exactly why proper diagnosis is so important before any part is replaced.
Replacing a PCB involves safely isolating power and gas, transferring or re-entering configuration settings, confirming sensor and actuator wiring, and running a full commissioning test. Boards are also among the more expensive components, so confirming the board is genuinely the cause — and not a cheaper sensor or connector — protects you from an unnecessary repair.
Common signs of a control board fault
- Boiler won't power on or display is blank/garbled
- Random lockouts or error codes that don't match any single component
- Pump, fan or ignition behaving erratically
- Settings reset themselves or won't save
- Intermittent operation that comes and goes with no clear pattern
Our diagnosis-first approach
Because PCBs are costly and their symptoms overlap with sensor, wiring and connector faults, we always confirm the diagnosis before recommending replacement. Many "board" faults turn out to be a failed flame sensor, a corroded connector or a faulty thermistor — far cheaper fixes. We test methodically so you only pay for the part you actually need.
Why a certified technician is required
Control board work involves mains electricity, the gas valve and the appliance's safety interlocks. Incorrect wiring or configuration can disable safety functions or damage the new board. Under BC code this is licensed work — and manufacturers require certified installation to keep your warranty valid.
This is not a DIY repair
Combi boilers are gas-fired appliances regulated under the BC Safety Standards Act. Opening the unit, touching the gas valve, or working on the flue without a valid BC gas-fitter licence is both unsafe and illegal. Diagnosing the fault is helpful — fixing it should always be left to a certified technician.
Call 778-909-5731Frequently Asked Questions
Get an Accurate, Diagnosis-First Repair
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