How do I fix Potterton E28?

Try first: Try resetting the boiler once (your manual shows how); If the code comes straight back, it needs a Gas Safe engineer — don't open the boiler yourself. If that doesn't clear it, the likely part is Flue thermistor.

Potterton E28 Fault — What It Means & Fix Cost

⚠ This is the likely cause from the code — a Gas Safe registered engineer confirms it on site. If you can smell gas, stop and ring 0800 111 999.

✅ Try these first — they're free

Often clears it without a callout:

Try resetting the boiler once (your manual shows how)
If the code comes straight back, it needs a Gas Safe engineer — don't open the boiler yourself

🔧 If that doesn't fix it

The likely cause is one of these — the engineer confirms which:

Most likely part: Flue thermistor

What it costs

Fixed price,
no callout fee

Free diagnosis first, then one fixed price for the repair — you only pay if you go ahead.

A vetted Gas Safe engineer who covers your postcode will call you back to arrange the repair. No callout fee — you only pay if you go ahead.

Other Potterton fault codes

Potterton E09Gas valve wiring or connection fault.…Potterton E10Outdoor (external) sensor fault.…Potterton E109Poor circulation around the system.…Potterton E110The boiler has overheated and tripped — often a stuck pump o…

Potterton E28 — what it means

✅ Try these first — they're free

🔧 If that doesn't fix it

Other Potterton fault codes

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