i13 Low

Worcester Bosch i13 Fault Code

Also written as I13 — same fault.

The Worcester Bosch i13 fault code means: this is not an error code, but rather a live status display showing the current temperature of the internal water store inside your boiler.. It appears on 1 Worcester Bosch model in our database.

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.

Technical description: Thermal store current temperature - This is the thermal store current temperature, displayed in real time (rounded to 0.5°C units).

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 for a qualified engineer in your area.

Gas Safe Register →
Boiler cover options

Avoid the next call-out bill

A cover plan would handle faults like i13: 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.

Worcester Bosch models that show the i13 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Worcester Bosch i13 fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026