Warmflow E22 Fault Code: Causes, Fixes & Repair Costs
What does the Warmflow E22 fault code mean?
The E22 code on a Warmflow boiler carries two distinct meanings depending on which model you own. On GS-Series gas boilers (such as the GS25A), E22 signals a parameter or fan-related fault — the boiler's control system has detected a problem with the fan circuit, causing the appliance to shut down as a safety precaution. Without a working fan, combustion gases cannot be safely expelled through the flue, so the boiler locks out to protect occupants. On the Agentis combination boiler range, E22 specifically indicates 'Flash Data Corrupted', meaning the PCB's onboard memory has encountered a storage or data integrity problem. In both cases the boiler will stop operating until the underlying fault is resolved. Always check your model's manual to confirm which interpretation applies to your specific appliance.
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
- Fan motor wear or failure Common
The boiler fan draws combustion gases out through the flue. Over time, the motor windings can burn out and the bearings can deteriorate through normal wear, causing the fan to run erratically or stop altogether. The boiler's control board detects the fault and locks the boiler out.
- Wiring fault between fan and PCB Common
Loose, damaged, or corroded wiring between the fan and the main PCB (or between the fan PCB and the modulator PCB on applicable models) can cause the control board to read no signal from the fan even if the fan itself is physically intact.
- Corrupted PCB memory (Agentis models) Sometimes
On the Agentis range, E22 points directly to a flash memory or data corruption issue on the control board itself. This can be triggered by a power surge, a failing PCB component, or an internal software error within the controller.
- Fan speed out of acceptable range Sometimes
Even when the fan is physically spinning, if its speed falls outside the parameters the boiler expects — due to partial motor degradation or a build-up of debris — the control board may still raise an E22 fault.
How to fix it
- Identify your Warmflow model DIY safe
Before doing anything else, confirm whether you have a GS-Series or Agentis boiler. Check the model label on the front or inside the boiler casing. This determines whether E22 is a fan-circuit fault or a flash data / PCB fault, and will help your engineer diagnose it faster.
- Attempt a single boiler reset DIY safe
Press and hold the reset button on the control panel as described in your user manual. Wait for the boiler to attempt a restart. If it fires up and runs normally, monitor it closely over the next 24 hours. If the E22 code returns promptly, do not keep resetting — repeated resets will not fix an underlying hardware fault and may mask important diagnostic information for your engineer.
- Check your gas supply DIY safe
Make sure other gas appliances in your home (hob, gas fire) are working normally. If there is no gas supply to the property, contact your gas supplier rather than an engineer. A total gas outage can sometimes cause boiler lockouts that are misread as component faults.
- Do not attempt to inspect or replace the fan or PCB yourself Gas Safe engineer
Accessing the fan, wiring, or control board requires opening the boiler casing and working near live electrical terminals and gas components. This work must only be carried out by a Gas Safe registered engineer. Attempting it yourself is dangerous and will invalidate any remaining warranty.
- Call a Gas Safe registered engineer to diagnose and repair the fault Gas Safe engineer
For a fan-circuit E22, the engineer will check fan speed, inspect wiring connections between the fan and PCB, and either tighten connections or replace the fan assembly as needed. For a flash-data E22 on an Agentis boiler, the engineer should first verify other components (heat exchanger, pump, gas valve) are functioning correctly before concluding the PCB needs replacement, as a PCB swap is costly and should be a last resort.
Parts you may need
- Boiler fan / flue fan assembly · from £120
- Fan wiring harness · from £30
- PCB (main control board) · from £220
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 £225–£400, depending on the underlying cause.
Frequently asked questions
Why does E22 mean something different on my Warmflow compared to what I read online?
Warmflow use the same error code numbers across different boiler ranges, but the meanings are not always identical. E22 is a fan or parameter fault on the GS-Series and a flash data corrupted fault on the Agentis range. Always cross-reference the fault code against your specific model's manual, or tell your engineer your exact model name so they can use the correct fault-finding table.
Can I reset the boiler myself to clear the E22 code?
You can try a single reset using the button on the control panel. Occasionally a one-off glitch can trigger a temporary lockout that clears after a reset. However, if the E22 code comes back after one or two attempts, stop resetting and call a Gas Safe engineer. Repeatedly resetting a boiler with a genuine fan or PCB fault will not fix it and could complicate diagnosis.
How much does it cost to fix a Warmflow E22 fault?
If the issue is the fan, most homeowners pay in the region of £225–£300 for parts and labour combined. If the fault is traced to the PCB on an Agentis boiler, the repair typically costs £300–£400 all-in, though on some models PCB parts alone can push the total higher. If your boiler is older or out of manufacturer warranty and the PCB needs replacing, it is worth asking your engineer whether a new boiler installation would be more cost-effective in the long run.
Is the Warmflow E22 fault dangerous?
The boiler locks itself out when it detects an E22 condition, so it will not attempt to run in an unsafe state. However, you should not attempt to bypass the lockout or open the boiler casing yourself. Leave the boiler switched off and arrange for a Gas Safe registered engineer to inspect it. If you smell gas at any point, leave the property, avoid operating electrical switches, and call the National Gas Emergency Service on 0800 111 999.