Potterton E152 Fault Code: Causes, Fixes & Repair Costs
What does the Potterton E152 fault code mean?
The E152 code indicates that the boiler's PCB (Printed Circuit Board) has detected a second-type internal fault within its own circuitry. The PCB acts as the control centre of your Potterton boiler, coordinating every component from the fan and ignition through to the pump and gas valve. When it logs this fault, the boiler will typically lock out completely and refuse to fire until the underlying issue is resolved. E152 is considered a more serious variant of the related E151 code — both point to PCB self-diagnostics flagging a problem, but E152 suggests a deeper or more persistent internal failure. Because the PCB communicates with components such as the fan and air pressure switch, a fault in any part of that chain can sometimes cause the PCB to log E152 even when the board itself is not the root cause.
General guidance only — not a substitute for professional advice, and not certified by a Gas Safe engineer. Always have your specific appliance assessed by a qualified professional. Any gas work must be carried out by a Gas Safe registered engineer. If you smell gas or suspect carbon monoxide, leave the property and call the National Gas Emergency line on 0800 111 999.
Common causes
- Failed or faulty PCB Common
The PCB may have developed an internal hardware fault, meaning it can no longer send or receive the correct signals to operate the boiler. This can happen through age, component degradation, or a sudden electrical failure. A complete board failure will trigger E152 and prevent any reset from holding.
- Water ingress or leak damage to the PCB Common
Leaks from internal components — such as the heat exchanger, pump, or pipe connections — can allow moisture to reach the PCB. Even minor water exposure can short-circuit tracks on the board or corrode connectors, producing exactly this type of internal fault code.
- Loose, corroded, or damaged wiring Common
The PCB relies on a network of wiring looms to communicate with components like the fan, air pressure switch, and sensors. A loose connector or a wire that has chafed through its insulation can cause intermittent or missing signals that the PCB interprets as an internal fault, even if the board itself is physically intact.
- Fan or air pressure switch fault Sometimes
The air pressure switch monitors whether the fan is running correctly by measuring air pressure inside the flue system. If the fan is running poorly or the pressure switch is sending an incorrect signal, the PCB may log E152 as it cannot verify safe flue conditions. This can sometimes be resolved without replacing the PCB.
- Power surge damage Sometimes
A significant mains voltage spike can damage the PCB's internal components and may also affect connected parts such as the fan or ignition system simultaneously. If E152 appeared shortly after a power cut or electrical storm, this is worth mentioning to your engineer.
- Faulty sensor sending incorrect data Rare
In some cases, a sensor elsewhere in the boiler — such as a thermistor or flow sensor — may be providing out-of-range readings that confuse the PCB into logging an internal fault. The PCB itself may be perfectly serviceable once the rogue sensor is identified and replaced.
How to fix it
- Reset the boiler once or twice using the reset button DIY safe
Most Potterton boilers have a dedicated reset button on the control panel. Press and hold it for around 3–5 seconds. If the boiler fires up and runs normally, monitor it over the next hour. If E152 returns promptly, do not keep resetting — repeated resets will not clear a genuine PCB or wiring fault and may mask useful diagnostic information for your engineer.
- Switch the boiler off at the mains, wait 30 seconds, then power it back on DIY safe
A full power cycle can occasionally clear a transient sensor error that caused the PCB to log a fault incorrectly. Turn the boiler off at the isolator switch or fused spur, wait at least 30 seconds, and restore power. If the code returns immediately or within a short test run, the fault is persistent and requires professional diagnosis.
- Check that your gas supply is working DIY safe
Confirm that other gas appliances in your home (such as a gas hob) are functioning. If there is no gas supply to the property, contact your gas supplier. A loss of gas supply is unlikely to cause E152 specifically, but it is a quick check worth doing before calling an engineer.
- Visually inspect for any obvious signs of a water leak near the boiler DIY safe
Look around the base of the boiler and any visible pipework for drips, water stains, or corrosion. If you see evidence of a leak, turn off the boiler and do not attempt to restart it — report this to your engineer as it may have contributed to PCB damage.
- Do not open the boiler casing or attempt to inspect or replace internal components Gas Safe engineer
All internal work — including inspecting the PCB, testing the wiring loom, checking the air pressure switch, or replacing any component — must be carried out by a Gas Safe registered engineer. Opening the casing and working on internal parts without the correct qualifications is both dangerous and illegal in the UK.
- Contact a Gas Safe registered engineer to diagnose and repair the fault Gas Safe engineer
An engineer will use electrical testing equipment to trace the fault systematically — checking the wiring loom for continuity, testing the air pressure switch signal, and evaluating the PCB itself. Depending on findings, the fix may be as straightforward as reseating a connector or as involved as a full PCB replacement. Ask for a written quote before authorising any parts.
Parts you may need
- Replacement PCB (Potterton compatible) · from £280
- Air pressure switch · from £45
- Fan assembly · from £120
- Wiring loom / harness · from £55
The exact spare depends on your boiler's GC number (on the data badge). Check this against the part before buying.
Typical repair cost
Expect to pay roughly £150–£500, depending on the underlying cause.
Frequently asked questions
Is E152 worse than E151 on a Potterton boiler?
Both E151 and E152 are PCB self-diagnostic fault codes, but E152 is generally considered the more serious of the two. E151 indicates a first-type internal PCB fault, which can sometimes be a transient error, whereas E152 points to a deeper or more persistent problem with the board's internal circuitry. In practice, neither code should be ignored — both require a Gas Safe engineer to investigate, and a persistent E152 often ends in PCB replacement.
Can a Potterton E152 ever fix itself after a reset?
Occasionally, if E152 was triggered by a brief power fluctuation or a momentary sensor glitch, a reset or power cycle will clear it and the boiler will run normally afterwards. However, if the code returns within a few hours or immediately after reset, the fault is genuine and will not resolve on its own. Continuing to reset the boiler repeatedly is not recommended — it will not repair damaged wiring or a failing PCB.
How much does it cost to replace a PCB on a Potterton boiler in the UK?
A PCB replacement on a Potterton boiler typically costs between £350 and £550 for parts and labour combined, with most jobs in 2025 falling around the £400–£500 mark. The PCB part itself usually ranges from around £180 to £350 depending on the specific model. London and the South East tend to sit at the higher end of that range. Note that if the board has been damaged by a water leak, the underlying leak must also be fixed at the same time, which adds to the total. If the repair cost approaches or exceeds half the cost of a new boiler — and your boiler is over ten years old — a full replacement may represent better value.
My Potterton boiler is over 10 years old and showing E152 — should I repair or replace it?
This is a common dilemma. As a general guide, if the repair cost exceeds roughly half the price of a comparable new boiler, replacement is usually the more sensible investment — particularly given that a modern A-rated condensing boiler will run more efficiently and lower your energy bills. A Gas Safe engineer can give you an honest assessment of your boiler's overall condition during the diagnostic visit, which should help you make an informed decision. If the boiler is still under a manufacturer's parts warranty and has been serviced annually, some or all of the PCB cost may be covered — check your warranty documentation before committing to a paid repair.