Boiler Repairs & Faults
Boiler PCB Replacement
A failing boiler PCB (printed circuit board) can cause lockouts, erratic heating, or a boiler that will not start. Boiler PCB replacement restores reliable control of your boiler safely, with proper testing to confirm the fault before any parts are fitted.
More information
What boiler PCB replacement covers
Boiler PCBs are the boiler’s control centre. This service is designed to identify PCB-related faults and get your heating and hot water working properly again.
- Fault finding using fault codes, measurements, and component checks
- Confirmation that the PCB is the cause, not wiring, sensors, pump, fan, or external controls
- Correct identification of the PCB for your boiler model and configuration
- Safe isolation, removal of the faulty board, and installation of the replacement
- Recommissioning and functional testing (start-up sequence, ignition, modulation)
- Safety checks and verification of correct boiler operation after repair
- Clear explanation of what failed and what was done to fix it
When this service is most suitable
PCB faults can look like several other problems, so this service is ideal when you need a confident diagnosis, not guesswork. It is commonly used when:
- The boiler keeps locking out or resets only temporarily
- There is no heating and or no hot water despite correct pressure and settings
- Fault codes point to control, ignition, fan, or communication issues
- The boiler behaves intermittently, especially after power cycling
- You have replaced external controls or batteries and the issue remains
How the service is delivered
The work starts with a structured fault-finding approach to avoid unnecessary parts.
- Initial checks: symptoms, fault history, and basic system condition.
- Testing: electrical checks, wiring integrity, component signals, and boiler feedback.
- Decision: confirm whether PCB replacement is the correct remedy.
- Replacement: fit the correct PCB and transfer any required settings or links.
- Commissioning: run the boiler through operating modes and confirm stable operation.
All gas-related work is carried out by a Gas Safe registered engineer.
After replacement: checks and next steps
Once the boiler is running, you should expect it to operate consistently and respond properly to heating and hot water demand.
- Final functional and safety checks are completed before sign-off
- You are talked through any settings, timers, or controls that may need adjustment
- If the original fault suggests wider issues (for example power quality or water ingress), you will be advised on practical next steps to help prevent repeat failures
Frequently Asked Questions
How do I know if my boiler PCB is faulty?
Common signs include repeated lockouts, intermittent operation, unexplained fault codes, or the boiler not responding to demand. A proper diagnosis is essential because similar symptoms can be caused by sensors, wiring, pumps, fans, or external controls.
Can a boiler PCB be repaired instead of replaced?
In most domestic and small commercial cases, replacement is the safest and most reliable option. Some boards can be repaired by specialist electronics services, but this is not always viable and can affect turnaround time and warranty.
How long does a boiler PCB replacement take?
If the correct PCB is available and access is straightforward, replacement and testing is often completed within a single visit. If the fault needs deeper diagnosis or parts must be ordered, it may take longer and require a return visit.
Will you confirm the PCB is the problem before fitting a new one?
Yes, testing is carried out to confirm the cause of the fault and reduce the risk of unnecessary parts. Where the evidence is unclear, you will be given the findings and options before any replacement goes ahead.
Is PCB replacement safe and does it need a Gas Safe engineer?
PCB replacement involves electrical work and recommissioning the boiler, and any gas-related checks must be completed by a Gas Safe registered engineer. Safety and operational checks are carried out after fitting the part to confirm correct performance.
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