Medium
S.53 on Glow-worm Energy7 System

Your boiler is temporarily pausing because it has detected that the water is not circulating properly or the system pressure is too low.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

Product in waiting period/operating block function due to water deficiency (flow/return spread too large)

From this model's manual
Verified against the Glow Worm Energy7 System installation & service manual, page 50.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Check your boiler's pressure gauge and ensure it is between 1.0 and 1.5 barIf the pressure is low, use the filling loop to top it up to the correct levelCheck that all your radiators are turned on and that the valves are fully open to allow water flow

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 S.53: 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

F.22View →F.23View →F.24View →

Related guides you might find useful

No hot water but heating works

Almost always a stuck diverter valve on combis.

Read →

Boiler keeps losing pressure

Six most common causes of dropping pressure.

Read →

Banging / kettling / whistling noise

Each noise points to a different fault.

Read →