Keston E38 Fault Code: Causes, Fixes & Repair Costs
What does the Keston E38 fault code mean?
The E38 code on a Keston boiler signals a reset key fault — meaning the boiler's internal diagnostics have detected a problem with the reset button or the fascia PCB (the printed circuit board sitting behind the front display panel). The boiler cannot confirm the reset button is operating correctly, so it locks out as a safety measure. Keston's own guidance points directly to replacement of the fascia PCB as the remedy. Because this fault sits within the boiler's control electronics, it is not something a homeowner can resolve without the help of a Gas Safe registered engineer.
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
- Faulty or stuck reset button Common
The reset button on the fascia panel may have become stuck, jammed, or short-circuited, causing the control board to read it as permanently pressed. This is one of the most straightforward root causes and can sometimes be traced to a physically damaged button rather than the PCB board itself.
- Failed fascia PCB Common
The fascia PCB can develop an internal electrical fault over time, often accelerated by moisture or condensation getting into the boiler casing. When the board itself fails, the reset key signal cannot be correctly sent or received, triggering the E38 lockout.
- Water ingress or moisture damage Sometimes
Keston boilers occasionally suffer from water ingress — either from a nearby pipework leak or from condensation. Moisture on the fascia PCB corrodes the delicate circuitry and can cause exactly this type of interface fault.
- Loose or damaged wiring between fascia and main PCB Sometimes
The ribbon cable or wiring harness connecting the fascia panel to the main control board can become loose, corroded, or damaged. A poor connection here can cause the boiler to misread the reset key status and trigger E38.
How to fix it
- Do not repeatedly press the reset button DIY safe
It is tempting to keep hitting reset in the hope the boiler comes back on, but doing so with a fascia PCB fault can stress the board further. Try a single reset — if the E38 code reappears, leave the boiler switched off and avoid further resets.
- Switch the boiler off at the programmer or thermostat DIY safe
Turn the boiler off via your room thermostat or programmer and leave it for a few minutes. This removes any risk of you or an engineer accidentally triggering the boiler while investigating.
- Check for any obvious signs of a water leak near the boiler DIY safe
Have a look around the boiler casing for drips, damp patches, or corrosion marks. If you spot a leak, note its location to tell the engineer — water ingress is a common contributor to fascia PCB failure.
- Call a Gas Safe registered engineer — preferably one with Keston experience Gas Safe engineer
Keston boilers use a twin-flue design and a modulating pump, making them more complex than typical combi boilers. Not every engineer is familiar with them, so it is worth asking upfront whether they have worked on Keston appliances before. The engineer will inspect the wiring and connections first, before deciding whether the fascia PCB needs replacing outright.
- Engineer to inspect wiring harness and fascia connections Gas Safe engineer
Before condemning the fascia PCB entirely, a thorough engineer will check the ribbon cable and plug connections between the fascia and the main board. A loose connector is a quicker and cheaper fix than a new PCB.
- Engineer to replace the fascia PCB if required Gas Safe engineer
If wiring checks out, the fascia PCB itself will need to be sourced and replaced. Keston is now part of the Ideal Heating group, and parts can be ordered through them. The replacement process typically takes one to three hours and requires careful testing once the new board is fitted to confirm the fault has cleared.
Parts you may need
- Keston Fascia PCB (user interface board) · from £220
- Reset button / fascia keypad assembly · from £45
- Wiring harness / ribbon cable (fascia to main board) · from £30
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 £300–£550, depending on the underlying cause.
Frequently asked questions
Can I fix the Keston E38 fault myself?
No. Although you can safely try a single reset and check for obvious leaks, the E38 fault relates directly to the fascia PCB and its wiring — components that sit inside the boiler casing. Opening the casing and working on control boards requires a Gas Safe registered engineer. Attempting it yourself is unsafe and will also invalidate any remaining warranty.
How much does it cost to fix a Keston E38 fault in the UK?
Most people with this fault end up paying between £300 and £550 all-in, covering the engineer's call-out, labour (typically one to three hours), and the fascia PCB itself. If it turns out to be a loose wiring connection rather than a full PCB replacement, costs can be lower. In rare cases where the main control board is also affected, the total could climb higher — if your quote is approaching or exceeding £700, it is worth discussing whether a new boiler makes more financial sense, particularly if the appliance is over 12–15 years old.
Is it worth repairing a Keston boiler with an E38 fault, or should I replace it?
If your Keston boiler is under 10 years old and otherwise in good condition, replacing the fascia PCB is usually well worth doing — Keston boilers are high-efficiency appliances and the repair cost is a fraction of a new installation. However, if the boiler is 12–15 years old or has had multiple faults recently, it may be more cost-effective to invest in a replacement. A rough rule of thumb: if the repair bill is more than half the cost of a comparable new boiler, replacement is worth serious consideration.
Why should I look for an engineer with Keston-specific experience?
Keston boilers have a twin-flue design and a modulating pump that set them apart from standard combi or system boilers. Not all heating engineers work on them regularly, and unfamiliarity can lead to longer diagnosis times and higher labour costs. It is always worth asking a prospective engineer whether they have Keston experience before booking — or contacting Ideal Heating (Keston's parent company) for a referral to an approved engineer in your area.