Medium
F.353 on Viessmann Vitodens 222-F B2TF

Your boiler is not receiving enough gas to run at full power, so it has automatically lowered its performance to stay operational.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

Insufficient gas supply; burner output reduced

From this model's manual
Verified against the Viessmann Vitodens 222 F B2tf installation & service manual, page 96.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Check that your external gas meter has credit (if on a prepayment meter)Ensure your main gas emergency control valve is fully openCheck if other gas appliances, like a hob, have a strong flame to rule out a wider grid issue

Find a Gas Safe engineer
Search the official register →
Boiler cover options

Avoid the next call-out bill

A cover plan would handle faults like F.353: no call-out fees, no surprise bills.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.

Related fault codes

F.352View →F.351View →EbView →

Related guides you might find useful

Boiler keeps losing pressure

Six most common causes of dropping pressure.

Read →

Boiler won't turn on — 9-step checklist

Work through these before the call-out.

Read →

Pilot light keeps going out

Older boilers — thermocouple, draught, gas supply.

Read →