Low
H13 on Worcester Bosch Greenstar 12i System ErP

Your boiler is simply reminding you that its scheduled service interval has passed or it needs its service indicator reset.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

What the manual says

Manufacturer manual

The maximum maintenance interval set (in months), has exceeded or after the appliance has been placed into commissioning mode.

From this model's manual
Verified against the Worcester Bosch/Worcester Bosch Greenstar 12i System System 2 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.

Engineer required

This fault requires 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

Monthly cover means no unexpected bills when your boiler breaks down.

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

H07View →EAView →

All 13 fault codes on the Greenstar 12i System ErP

Seeing a different code? Every code this model can display, in one place.

226235328356360363H--H03H08H09H12H29

Related guides you might find useful

Boiler service cost

What a UK service costs and what a proper one includes.

Read →

Boiler keeps cutting out

Lockout fault with a reset-needed pattern.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →