Baxi Quinta Ace fault E.04.08
Safety input
ApplianceWhat it means
Safety input is open
Likely causes
- Air pressure differential switch out of calibration
- Faulty or blocked hoses to the differential switch
- Dirty connection points
- Bad connection
- Pressure in flue gas duct too high
- Non-return valve does not open
- Trap blocked or empty
- Blocked air supply inlet or flue gas outlet
- Dirty heat exchanger
Where to start
- Switch off the boiler.
- Remove any dirt from all connection points for hoses and the air pressure differential switch.
- Check the condition and tightness of the hoses of the air pressure differential switch, replace if necessary.
The full answer, free
- 10 more checks in order
- The readings and component tests from the manual
- How to put it right, step by step
- The manual page for this fault (page 81), right under the answer
Safety: Isolate gas and power before you open the case. If you have been into the gas side, do a tightness test, and a combustion and flue check before you hand back. Gas Safe (UK) or RGI (Ireland) work only.
From the Baxi manual for the Quinta Ace. Check the model on the data plate before you order parts.
Other Baxi Quinta Ace fault codes
- A.00.34TOutdoor missing
- A.01.23Poor combustion
- E.00.04TReturn open
- E.00.05TReturn closed
- E.00.06TReturn missing
- E.00.08THeat ex open
- E.00.09THeat ex closed
- E.00.20TFlue gas open
- E.00.21TFlue gas closed
- E.01.045x flame loss error
- E.01.12Return higher flow
- E.01.24Combustion error
- E.02.13Blocking input
- E.04.01TFlow closed
- E.04.04TFlue closed
- E.04.05TFlue open
- E.04.06Max flue temp
- E.04.10Unsuccessful start
- E.04.12False flame
- E.04.13Fan
- E.04.15FlueGas pipe blocked
- H.00.81RoomTempMissing
- H.01.05Max delta TF-TR
- H.01.06Max delta TH-TF