BoilerFaultCodesWhat the manual says
Manufacturer manualStatus of the heating demand: off=Heating off (Summer mode), on=Heating on
From this model's manual
Verified against the Vaillant/Vaillant Ecotec Plus 415 418 428 438 0020020828 02 2006 installation & service manual.
DIY fix possible
Check your room thermostat or boiler control panel to ensure the heating is switched to 'On'Increase the target temperature on your room thermostat to be higher than the current room temperatureEnsure the central heating timer or programmer is currently set within an 'On' period
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 d.23: no call-out fees, no surprise bills.
Approved partner
Get a quote →
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Affiliate links. We may earn a commission at no extra cost to you.
Related fault codes
All 96 fault codes on the ecoTEC plus 415
Seeing a different code? Every code this model can display, in one place.
cond.10d.11d.13d.17d.18d.19d.20d.22d.25d.27d.28d.33d.34d.35d.36d.40d.41d.47d.50d.51d.58d.60d.61d.64d.65d.67d.68d.69d.70F.0F.1F.10F.11F.13F.20F.22F.23F.24F.27F.28F.29F.32F.49F.61F.62F.63F.64F.65F.67F.70F.71F.72F.75F.76F.77F.78F22F70P.0P.1P.2P.3P.4P.5P.6S.0S.1S.2S.3S.4S.5S.6S.7S.8S.20S.21S.22S.23S.24S.25S.26S.27S.28S.30S.31S.32S.34S.36S.41S.42S.53S.54S.96S.98