Boiler PCB failure: when the circuit board really is the problem
The printed circuit board is the boiler's brain, and it is also the most over-diagnosed component in the trade. A board should only be condemned once everything it controls has been tested and cleared.
What matters most with a suspected PCB fault
- Always find out why a board failed before fitting another
- Water ingress and lightning surges are the common killers
- Boards are among the most expensive single boiler parts
- On older appliances the board can exceed replacement economics
- Ask for the tested evidence before agreeing to the part
A suspected PCB fault explained in plain terms
Genuine board faults show as dead displays with proven power in, outputs that never energise despite correct inputs, or scorched tracks visible on inspection. Water ingress from a leaking flue or a weeping fitting above the board is a frequent underlying cause, so replacing the board without fixing the leak simply buys a second failure.
Scope of work
- Domestic boiler installation
- Boiler servicing
- Boiler maintenance and repair
Where we deal with this
Questions we get asked
- Is a PCB worth fitting to a 14-year-old boiler?
- Often not. We will give you the repair cost against a replacement quote so the decision is yours with numbers in hand.
- Are refurbished boards reliable?
- Quality varies, and warranty terms differ. We discuss the trade-off rather than deciding for you.
Talk to us about a suspected PCB fault
Where this leaves you: Demand the diagnosis, not just the diagnosis fee. A proven board fault is fine; a guessed one is expensive.
Use the enquiry form to describe the appliance, fault code and what changed before the problem started.
Related help pages
- Ignition noiseLoud bang at ignition: what causes a noisy boiler start
- Baxi fault codeBaxi E119: low system pressure on a Baxi combi
- Baxi fault codeBaxi E133: gas supply or ignition failure on a Baxi combi
- Fuel qualitySludge and water in an oil tank: symptoms and remedies
- Insurance considerationsHow boiler servicing relates to buildings insurance requirements
- Brand comparisonGrant vs Worcester Bosch oil boilers
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