What does Potterton E109 mean?

Poor circulation around the system.

How do I fix Potterton E109?

Try first: Check the pressure gauge reads about 1–1.5 bar; Bleed your radiators to clear trapped air; Press reset once. If that doesn't clear it, the likely part is Pump or circulation.

Potterton E109 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:

Check the pressure gauge reads about 1–1.5 bar
Bleed your radiators to clear trapped air
Press reset once

🔧 If that doesn't fix it

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

Most likely part: Pump or circulation

Fixed repair price

£456

Inc. VAT — part & labour, no surprise callout fee. 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 E110The boiler has overheated and tripped — often a stuck pump o…Potterton E117System pressure is too high (over about 2.9 bar).…

Potterton E109 — what it means

✅ Try these first — they're free

🔧 If that doesn't fix it

Other Potterton fault codes

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