Low
S.0 on Vaillant ecoTEC 65kW

Your boiler is currently in standby mode because it has not received a request for heating or hot water from your thermostat or controls.

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

Heating:Noheatdemand

From this model's manual
Verified against the Vaillant Ecotec 65kw installation & service manual, page 34.
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 room thermostat is set to a temperature higher than the current room temperatureEnsure your external timer or programmer is currently set to an 'ON' periodCheck if any smart heating app or control hub is set to away mode or standby

Find a Gas Safe engineer
Search the official register →

Avoid the next call-out bill

A cover plan would handle faults like S.0: 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

Related guides you might find useful