Baxi Baxi 600/800/Assure System 2 and 600 Combi 2 platform fault GM044-9
Temperature difference between flow and return too great
Gas boilerWhat it means
Shutdown caused by excessive temperature differential between flow and return sensors, indicating poor circulation.
Likely causes
- Low water flow through heat exchanger
- Pump fault or blockage
- Air in system
Where to start
- Check pump operation and speed (AM010)
- Check system for air/blockage
- Check that the boiler pump venting valve is working
The full answer, free
- 1 more check in order
- How to put it right, step by step
- The manual page for this fault (page 59), 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 Baxi 600/800/Assure System 2 and 600 Combi 2 platform. Check the model on the data plate before you order parts.
Other Baxi Baxi 600/800/Assure System 2 and 600 Combi 2 platform fault codes
- A.02.06Low water pressure
- AC004Failed start-up attempts after last maintenance
- DC004Number of burner start-ups for DHW mode
- DC005Number of burner start-up hours for DHW mode
- E.01.04Flame loss detected five times in 24 hours
- E.01.12Return sensor temperature greater than flow temperature
- E.01.17No water circulation (permanent)
- E.01.20Maximum flue gas temperature reached
- E.04.08Maximum safe temperature value reached
- E.04.09Difference between flue gas sensors 1 and 2 temperature values
- E.04.10Burner failed to ignite after 4 attempts
- E.04.11VPS gas valve test failed
- E.04.12Ignition failure for monitoring parasitic flame
- E.04.14Temperature difference between set point and burner exceeds 60s vs GVC configuration
- E.04.15Flue gas exhaust pipe blocked
- E.04.23Gas valve check valve internal stoppage
- E.04.24Gas family not detected during automatic detection function
- E.04.54Fault in gas valve control circuit
- GC007Failed start-up attempts
- GM044-10Heating flow temperature above the shutdown value
- GM044-12Shutdown caused by flame value being too low
- GM044-3Awaiting burner ignition
- GM044-4Heating flow temperature above maximum value
- GM044-5Heating flow temperature above the starting value