High
1017 on Worcester Bosch Greenstar 8000+ GR8701iW 30 S

Your boiler has stopped working because the water pressure inside the system has dropped too low.

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

System pressure too low: 1. Top up water and vent the system. 2. Check the voltage to the pressure sensor and the signal back from the pressure sensor. 3. Replace the pressure sensor.

From this model's manual
Verified against the Worcester Bosch/Worcester Bosch Wb 47115 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 1017: 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

EAView →CE297View →

All 103 fault codes on the Greenstar 8000+ GR8701iW 30 S

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

200201202203204208214224227228229232233234235237238242244245246247248249250251252253254257258259262263265268269273281283284305306357358360362363604811815101010131018101910221023102510371065106810701071107210751076208529082910291429152916292029232924292529262927292829312940294629482949295029512952295529562957296129622963296529662968296929702971297229802981

Related guides you might find useful

What pressure should my boiler be?

1 to 1.5 bar when cold on most UK boilers, from the manuals.

Read →

Boiler keeps losing pressure

Six most common causes of dropping pressure.

Read →

Low pressure: how to repressurise

Step by step using the filling loop.

Read →