Low
S.31 on Glow-worm Flexicom 24c / 28c

Your boiler is currently set to summer mode, which intentionally turns off the heating and only provides hot water for your taps.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

What the manual says

Manufacturer manual

The summer mode is active or the eBUS control is blocking the heating mode.

From this model's manual
Verified against the Glow Worm/Glow Worm Flexicom 24c 28c installation & service manual, page 46.
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

Locate the mode selector button or dial on the front display panel of your boiler.Adjust the settings to switch the boiler from 'Summer' (tap icon only) to 'Winter' (radiator and tap icon).Check your external thermostat or smart home controller to ensure it is not currently set to a 'Summer' or 'Off' heating schedule.

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.31: 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

S.30View →

All 141 fault codes on the Flexicom 24c / 28c

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

d.00d.01d.02d.05d.06d.08d.09d.10d.11d.13d.14d.15d.16d.17d.18d.20d.21d.22d.23d.27d.28d.33d.34d.35d.36d.39d.40d.41d.43d.45d.47d.50d.51d.58d.60d.61d.62d.64d.65d.67d.68d.69d.71d.80d.81d.82d.83d.85d.88d.90d.93d.94d.96F.00F.01F.10F.11F.13F.20F.22F.23F.24F.25F.27F.28F.29F.32F.33F.46F.49F.61F.62F.63F.64F.65F.67F.68F.70F.71F.72F.73F.74F.76F.77F.78F.83F.84F.85F.86F.87F.88F.89F.97F01F10F11F13F17F20F22F25S.00S.01S.02S.03S.04S.05S.06S.07S.08S.10S.11S.13S.14S.15S.16S.17S.20S.21S.23S.24S.25S.26S.27S.28S.30S.32S.34S.39S.41S.42S.46S.53S.54S.58S.76S.88S.91S.96S.98

Related guides you might find useful

No hot water but heating works

Almost always a stuck diverter valve on combis.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →