Vokera Synergy fault AF2
Heating anti-freeze function active
Gas boilerWhat it means
Heating anti-freeze protection function. Starts if the temperature detected by the flow sensor falls below 5°C. A heat request is generated with burner ignition at minimum output, maintained until water delivery temperature reaches 35°C. Display shows AF2.
Likely causes
- Low ambient/system temperature near freezing
- Flow sensor detecting temperature below 5°C
Where to start
- Confirm electrical supply and fuel supply remain active
- Check flow sensor temperature reading
The full answer, free
- The readings and component tests from the manual
- How to put it right, step by step
- The manual page for this fault (page 36), 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 Vokera manual for the Synergy. Check the model on the data plate before you order parts.
Other Vokera Synergy fault codes
- AF1DHW anti-freeze function active
- E010Flame lockout
- E033Rotor fan failure damaged
- E034Chimney obstruction in preventilation
- E035Blockage obstruction flue gas low power
- E036Blockage obstruction flue gas high power
- E040Water pressure low, fill the system
- E041Fill the system
- E050Smoke obstruction error low power
- E051Result of a calibration performed under flame instability/obstruction conditions
- E055No card fan communication
- E091Heat exchanger requires cleaning (unusual usage threshold reached)
- E092Calibration failed, excessive number of calibrations within the hour
- E093Too many calibration attempts
- E095Calibration failed
- E099Reset attempts exhausted