High
8/1/0 on Worcester Bosch GB162

Your boiler is failing to heat your water, likely due to a loose wire or a faulty sensor that is preventing the system from identifying the water temperature correctly.

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

The boiler water does not warm up. Sensor lead broken or shorted, sensor connected incorrectly or defective, filling pump connected incorrectly or defective.

From this model's manual
Verified against the Worcester Bosch Gb162 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 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 8/1/0: 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

8/1/1View →

Related guides you might find useful

Banging / kettling / whistling noise

Each noise points to a different fault.

Read →

Yellow or orange flame — CO safety

Safety-critical — turn off, read this.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →