Medium
S.54 on Glow-worm Energy7 Combi

Your boiler is temporarily pausing because it cannot detect enough water flowing through the system to heat your home properly.

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

Waiting period: Water deficiency in the circuit (flow/return spread too large)

From this model's manual
Verified against the Glow Worm Energy7 Combi installation & service manual, page 51.
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 and 1.5 barIf the pressure is low, use the filling loop to top up the water in the systemCheck all radiators for trapped air and bleed them if necessary

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.54: 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 →S.53View →

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 →