High
Low water pressure on Keston 30C

Your boiler has detected that there is not enough water in the system to operate safely, which is usually caused by a small leak or air being bled from radiators.

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

Low water pressure

From this model's manual
Verified against the Keston 30c installation & service manual, page 64.
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 Low water pressure: 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

E02View →E40View →

Related guides you might find useful

Boiler keeps losing pressure

Six most common causes of dropping pressure.

Read →

Low pressure — repressurise guide

Step-by-step using the filling loop.

Read →

Radiators cold at the bottom

Sludge build-up — needs flushing, not bleeding.

Read →