Low
A short pulse every 4 seconds on Biasi Riva Compact HE M96a

Your boiler is currently switched off but is working correctly to protect itself from freezing during cold weather.

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

Boiler in stand-by condition (function control in OFF position). Anti-freeze system active.

From this model's manual
Verified against the Biasi Riva Compact 24s installation & service manual, page 23.
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

Turn the main selector switch to the 'ON', 'Summer', or 'Winter' position to begin normal operation.Ensure your external room thermostat is turned up if you require heating.No action is required if you intended for the boiler to stay off, as the light simply confirms frost protection is active.

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 A short pulse every 4 seconds: 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 guides you might find useful

Yellow or orange flame — CO safety

Safety-critical — turn off, read this.

Read →

Frozen condensate pipe

Winter cause of ignition lockouts.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →