BoilerFaultCodesWhat the manual says
Manufacturer manualSafetyswitch-off:Temperaturelimiter | Incorrectearthconnectionbetweencableharnessandproduct,floworreturnNTCdefective(looseconnection),straysparkviaignitioncable,ignitionplugorignitionelectrode. Onlyinliquefiedpetroleumgasoperationorincascademode:Thedifferentialpressuresensorwasnotreplacedwithabypassvalve;thebypassvalveisnotfunctional
From this model's manual
Verified against the Vaillant/Vaillant Vaillantpro 0020193966 04 Ecotec Exclusive System Installation I installation & service manual.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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 F.20: 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.
All 120 fault codes on the ecoTEC exclusive 627
Seeing a different code? Every code this model can display, in one place.
D.118-1D.118-2D.118-3D.118-4D.118-5D.118-6D.118-7D.118-8D.118-9D.118-10D.118-11D.118-12D.118-13D.118-14D.118-15D.118-16F.00F.01F.02F.03F.10F.11F.12F.13F.22F.23F.24F.25F.26F.27F.28F.29F.32F.33F.35F.42F.49F.55F.56F.57F.61F.62F.63F.64F.65F.67F.68F.70F.71F.72F.73F.74F.75F.77F.78F.80F.81F.82F.83F.84F.85F.90F.94S.00S.01S.02S.03S.04S.05S.06S.07S.08S.09S.10S.11S.13S.14S.15S.16S.17S.19S.20S.21S.22S.23S.24S.25S.26S.27S.28S.29S.30S.31S.32S.33S.34S.36S.37S.39S.40S.41S.42S.46S.53S.54S.55S.56S.57S.58S.59S.76S.86S.88S.92S.93S.96S.97S.98S.99