BoilerFaultCodes.com

Vaillant EcoTEC Pro / EcoTEC Plus Fault Codes

CombiSystemRegular Natural GasLPG 24-38 kW 2005-present
GC Numbers: 47-044-3247-044-3347-044-3147-044-4347-044-4447-044-4541-044-4841-044-4941-044-5041-044-5141-044-5241-044-5318-044-0118-044-0218-044-0318-044-0418-044-0547-044-5147-044-5247-044-5347-044-8247-044-8347-044-8441-044-7141-044-7241-044-7341-044-7441-044-75

The fault code is already on your display

Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

Most common fault codes

S13
Your boiler is struggling to light properly when you turn on your hot water taps.
Gas Safe engineer required · £100-280

All 1 fault code

Code Severity Plain English
S13 High Your boiler is struggling to light properly when you turn on your hot water taps.

Status & diagnostic codes

These codes indicate your boiler's operating state or a diagnostic reading — not necessarily a fault. Status codes (S.) mean normal operation; diagnostic codes (D.) are informational readings used by engineers.

Code Type Description
S.00 Status Your boiler is working correctly but is currently idle because your thermostat or programmer is not telling it to turn on the heating.
S.01 Status Your boiler is currently preparing to start the heating cycle and is warming up the internal fan.
S.02 Status Your boiler is currently preparing for heating by circulating water, but it has not yet fired the burner to create heat.
S.03 Status Your boiler is trying to start up to provide heating, but it keeps failing to light the flame correctly.
S.04 Status Your boiler is operating normally and is currently firing the burner to provide central heating to your home.
S.06 Status Your boiler is staying in a cooling-down phase for too long because it thinks the fan is still spinning after it should have stopped.
S.07 Status Your boiler is briefly running the pump after the heating has switched off to cool the system down, but it is taking longer than expected to move the residual heat away.
S.08 Status Your boiler is temporarily resting because it has reached its target temperature and is waiting for a short period before restarting to prevent unnecessary wear.
S.10 Status Your boiler has detected that you have turned on a hot water tap and is currently working to provide hot water to your home.
S.11 Status Your boiler is trying to heat your water, but the internal fan responsible for safety cannot get started.
S.14 Status Your boiler is confused and thinks you are asking for hot water even though your taps are turned off, preventing the heating from starting.
S.15 Status Your boiler is briefly keeping the internal pump and fan running to clear away excess heat after you have finished using hot water.
S.16 Status Your boiler's fan is still spinning after the hot water has been turned off, preventing the system from restarting safely.
S.17 Status Your boiler is busy cooling itself down after providing hot water, but the water isn't moving through the system as quickly as it should.
S.20 Status Your boiler has detected an error while trying to heat your water, preventing the burner from lighting or staying on correctly.
S.21 Status Your boiler is struggling to start the fan when you turn on your hot water taps, meaning the system cannot safely clear exhaust gases to begin heating.
S.22 Status Your boiler has detected that hot water is being called for, but it believes the pump is running when it shouldn't be or there is a circulation issue preventing proper operation.
S.23 Status Your boiler is having trouble lighting the flame when you turn on your hot water taps.
S.24 Status Your boiler is struggling to keep the flame lit while trying to heat your tap water, which usually means the system is cutting out during use.
S.25 Status Your boiler is temporarily cooling itself down after finishing a cycle for hot water.
S.26 Status Your boiler is simply cooling itself down by running the fan after you have finished using hot water.
S.27 Status Your boiler is briefly running the pump after heating your water to cool down the internal components and prevent them from overheating.
S.28 Status Your boiler is taking a short, programmed break to prevent the burner from starting and stopping too frequently while heating your water.
S.30 Status Your boiler is working correctly but is currently in a 'waiting' state because your room thermostat is telling it that the house is already warm enough.
S.31 Status Your boiler is currently set to only provide hot water and is ignoring your request for central heating.
S.32 Status Your boiler is temporarily pausing because the internal fan is not spinning at the correct speed needed to safely light the burner.
S.34 Status Your boiler has paused operation because it believes the internal temperature is so low that the pipes are at risk of freezing.
S.39 Status Your boiler has temporarily stopped running because an external safety device, such as a condensate pump or a pipe thermostat, has detected a potential issue and sent a signal to shut the burner down.
S.40 Status Your boiler has detected a minor inconsistency in its temperature readings and has slightly reduced its power to ensure it continues to provide heating and hot water safely.
S.41 Status Your boiler has too much water in the system, causing the pressure to rise to a level that is higher than recommended for safe operation.
S.42 Status Your boiler has temporarily paused because a safety flap in the flue system is not providing the correct signal to allow the burner to start.
S.46 Status Your boiler is struggling to keep a steady flame when it is running at its lowest power setting, causing it to operate in a restricted safety mode.
S.53 Status Your boiler is pausing temporarily because it is struggling to circulate water quickly enough to keep the system cool.
S.54 Status Your boiler has temporarily paused operation because it detected a sudden rise in temperature and is waiting for the system to cool down or balance itself.
S.57 Status Your boiler has temporarily paused operation to prevent potential overheating and will restart automatically once it has cooled down.
S.58 Status Your boiler is temporarily reducing its power because outside wind or atmospheric conditions are affecting the burner flame.
S.61 Status Your boiler has failed a safety check during its start-up sequence because it cannot identify the gas type or verify the flame correctly.

Protect yourself from future repair bills

Monthly cover means no unexpected bills when your boiler breaks down.

Top rated
OpenFix
Boiler & heating care plans
Get a quote →
Hometree
from £12.95/month
Get a quote →
HomeServe
from £8.00/month
Get a quote →

Affiliate links — we may earn a commission at no extra cost to you.