Low
S.31 on Heatline CaprizPlus 24a

Your boiler is currently set to run the hot water only, meaning your central heating is temporarily disabled by the user settings.

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

"Hot water only" mode

From this model's manual
Verified against the Heatline Caprizplus 24a installation & service manual, page 26.
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 knob on the control panelSwitch the setting from 'Hot Water Only' (Summer Mode) to 'Heating and Hot Water' (Winter Mode)Check that your room thermostat is turned up to call for heat

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 →S.34View →

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 →