Johnson & Starley F13 Fault Code: Causes, Fixes & Repair Costs
What does the Johnson & Starley F13 fault code mean?
F13 on a Johnson & Starley unit is a remote reset lockout: the appliance has locked out after too many reset attempts — typically via a room controller or repeated resets in a short window — and now refuses further remote resets. Controls count resets deliberately: each reset on a locked-out gas appliance re-attempts ignition, and unlimited retries against a genuine fault mean repeated gas admissions into an appliance that keeps failing to light. When the count is exceeded, the unit escalates to a state only clearable at the appliance itself, or by an engineer — which is precisely the point: something has caused the underlying lockouts, and it needs diagnosing rather than resetting again.
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
- Repeated resets against an unresolved fault Common
The unit kept locking out for a real reason — ignition, overheat, sensor — and each reset re-triggered it until the counter ran out. F13 is the symptom; the earlier code is the disease.
- Room controller repeatedly issuing resets Sometimes
A controller or automation retrying automatically burns through the reset allowance fast; worth checking if nobody was pressing buttons.
- Control fault miscounting Rare
Rarely the counter itself misbehaves; considered only when there is no history of underlying lockouts.
How to fix it
- Stop resetting — note what code came before DIY safe
The code the unit showed before F13 is the real fault. Write it down for the engineer; it shortcuts the diagnosis considerably.
- One full power-cycle at the appliance, if you must DIY safe
Switching off at the fused spur for a minute may clear the remote-reset latch on some models — but if the unit then locks out again, leave it off. The pattern is telling you the fault is real.
- Have a Gas Safe registered engineer complete the documented checks Gas Safe engineer
The engineer will read the fault history, diagnose the underlying lockout that consumed the resets, repair it, and clear the counter — returning the unit to service only once the actual fault is fixed.
Parts you may need
- Depends on the underlying fault 0
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 £90–£350, depending on the underlying cause.
Frequently asked questions
What does F13 mean on my Johnson & Starley?
The unit has been reset too many times against a fault that kept coming back, so it now refuses remote resets. It is protecting itself: repeated resets against a genuine fault mean repeated failed ignitions. Note whatever code appeared before F13 — that is the fault the engineer needs to fix.
Can I clear it myself?
A full power-cycle at the fused spur sometimes clears the latch — but the underlying fault will bring it straight back. The productive move is diagnosis of what caused the earlier lockouts, not another way to press reset.
Why do boilers limit resets at all?
Every reset on a locked-out gas appliance is a fresh attempt to admit and ignite gas. Doing that indefinitely against a fault is exactly what the lockout system exists to prevent — the counter turns a bad habit into a hard stop.