High
1013 on Worcester Bosch Greenstar 1000

Your boiler has detected that the burner is running at its maximum capacity for too long, causing it to proactively shut down to prevent overheating.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

Max. combustion point reached

From this model's manual
Verified against the Worcester Bosch Worcester Bosch Greenstar 1000 installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

Operating limit reached

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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 1013: 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 guides you might find useful

No hot water but heating works

Almost always a stuck diverter valve on combis.

Read →

Banging / kettling / whistling noise

Each noise points to a different fault.

Read →

Boiler keeps cutting out

Lockout fault with a reset-needed pattern.

Read →