Intergas F028 Fault Code: Causes, Fixes & Repair Costs
What does the Intergas F028 fault code mean?
The F028 code appears on Intergas Xclusive and Xtreme boilers when the PCB has detected an unexpected or repeated reset signal. In simple terms, the boiler's control board has registered a reset event it wasn't expecting — this could be as straightforward as the reset button being accidentally activated, or it could point to a deeper electrical problem with the board itself, or incorrectly mounted sensors triggering abnormal behaviour. When F028 triggers, the boiler locks out and stops functioning until the underlying cause is properly addressed.
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
- Accidental reset button activation Common
The most common trigger for F028 is the reset button on the boiler fascia being pressed unintentionally — for example, during routine cleaning of the front panel, or something resting against the controls. The PCB interprets this as a spurious reset signal and locks the boiler out.
- Faulty PCB Common
If there is no obvious physical explanation for the reset signal, the control board itself is likely at fault. The PCB can develop internal faults that cause it to register false reset events. This is the most significant and costly outcome, as the board will need to be replaced by an engineer.
- Heat exchanger sensor (S0) not correctly seated Sometimes
If the primary heat exchanger sensor S0 is loose or displaced from its correct mounting position, it can feed erratic temperature data to the PCB, contributing to abnormal fault conditions including F028. An engineer will need to check the sensor is properly located and secured, and verify its wiring and resistance readings.
- Domestic hot water sensor (S3) incorrectly mounted or faulty Sometimes
Similarly, the DHW sensor S3 sitting out of position or with degraded wiring can cause the board to receive inconsistent signals. If re-seating the sensor does not resolve the issue, the sensor itself may need to be replaced.
How to fix it
- Check the boiler fascia for any obvious obstruction near the reset button DIY safe
Look at the front panel of the boiler and check whether anything is pressing against the reset button — a cloth, a shelf bracket, or anything stored nearby. If you find an obstruction, remove it and then press the reset button once deliberately to attempt a clean restart. Only reset the boiler once or twice; repeated resets without resolving the fault can place unnecessary stress on the PCB.
- Do not attempt repeated resets if the fault returns DIY safe
If F028 reappears after a single reset, switch the boiler off at the programmer or room thermostat and leave it alone. Continually resetting a locked-out boiler is unlikely to clear the fault and may make diagnosis harder for the engineer.
- Contact a Gas Safe registered engineer to inspect the PCB and sensors Gas Safe engineer
An engineer should carry out a full assessment of the control board, check the reset button mechanism for sticking or internal faults, and verify that the heat exchanger sensor S0 and DHW sensor S3 are correctly mounted and reading accurately. Wiring continuity and sensor resistance values should be tested against Intergas specifications.
- Engineer to re-seat or replace faulty sensors if required Gas Safe engineer
If either sensor is found to be out of position, the engineer will re-mount it correctly. If the sensor has failed electrically — indicated by out-of-range resistance readings — a replacement sensor will be fitted. This alone may clear the F028 code.
- Engineer to replace the PCB if sensors are not the cause Gas Safe engineer
When the reset button and sensors check out correctly but F028 persists, the PCB itself is the likely culprit. Replacement involves sourcing the correct board for your specific Intergas model — which the engineer may need to order in — and fitting and commissioning it. This is the most involved and expensive resolution for F028.
Parts you may need
- Intergas PCB (control board) · from £280
- Heat exchanger sensor S0 · from £35
- Domestic hot water sensor S3 · from £35
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 £100–£400, depending on the underlying cause.
Frequently asked questions
Can I fix Intergas F028 myself by just resetting the boiler?
You can try a single reset if there is an obvious reason for it — such as something having accidentally pressed the reset button on the fascia. However, if the F028 code comes back after one reset, further resets are unlikely to help and you should call a Gas Safe registered engineer. The fault points to a PCB or sensor issue that requires professional diagnosis and repair.
How much does it cost to fix an Intergas F028 fault?
If the cause is a simple sensor re-seating or a call-out with no parts needed, most homeowners pay between £100 and £250. If a temperature sensor needs replacing the cost typically sits in the £120–£280 range including labour. A PCB replacement — the most serious outcome — generally costs £450–£700 in the UK once parts and labour are included, and the engineer may need to order the board in specially, adding a day or two to the process.
Is it worth replacing the PCB on an older Intergas boiler?
It depends on the age and overall condition of the boiler. On a newer Intergas, a PCB replacement is usually worthwhile as it restores full function and the rest of the system should have plenty of life left. For a boiler that is ten years or older, or one where other components are already showing wear, it is worth getting an honest assessment from your engineer about whether replacement offers better long-term value. As a rough guide, if the repair bill exceeds half the cost of a new boiler, a replacement is often the more sensible investment.
Why is the F028 code appearing when I haven't touched the boiler?
F028 can appear without any obvious interaction with the boiler because a deteriorating PCB can generate spurious reset signals internally, without the physical button being pressed at all. It can also appear if a sensor has worked loose over time due to vibration. Neither scenario requires you to have done anything wrong — these are internal component faults that a Gas Safe engineer will need to diagnose properly.