Viessmann fault code F A7
Fault code F A7 on a Viessmann boiler (including Vitocrossal 300) means: Ionisation electrode incorrectly set, plug of the ionisation cable not connected Ignition electrodes incorrectly set Insulation sheath of the ignition electrodes cracked Incorrect gas type set Combination gas valve does not open Connections "L 1" and "N" of the mains connection of the controller or of the burner control unit swapped Combustion values not optimal. Reset the appliance once. If the code comes back, a part is usually faulty.
After a safety alert (gas, flue gas, combustion), reset no more than once and call in a certified gas engineer. If you smell gas, call your national gas emergency number or 112 immediately.
Cause
Fault code F A7 on a Viessmann boiler indicates: Ionisation electrode incorrectly set, plug of the ionisation cable not connected Ignition electrodes incorrectly set Insulation sheath of the ignition electrodes cracked Incorrect gas type set Combination gas valve does not open Connections "L 1" and "N" of the mains connection of the controller or of the burner control unit swapped Combustion values not optimal.
Applies to
Viessmann Vitocrossal 300, -.
Click a model for the parts list and exploded view of that appliance.
Matching parts
Viessmann parts are available from Instalpunt; shipping to EU countries from €17.95 (€24.95 for more distant countries), usually 3–5 working days.
This message does not point directly to one faulty part. These are the parts that most often fit this appliance:
- Viessmann siphon Vitocrossal 300 € 35.28
- Viessmann inspection hatch gasket vsb 72/89 gf 10x10 l=700 mm € 44.43
- Viessmann flue gas gasket 2nd heat exchanger Vitocrossal 300 720kW € 95.40
Fix it yourself or call an engineer?
Always consult the manual for your appliance and work safely. If in doubt or if the fault comes back, call in a qualified professional. A question about a part? Write to us at info@instalpunt.nl.
Frequently asked questions
What does Viessmann boiler fault code F A7 mean?
Ionisation electrode incorrectly set, plug of the ionisation cable not connected Ignition electrodes incorrectly set Insulation sheath of the ignition electrodes cracked Incorrect gas type set Combination gas valve does not open Connections "L 1" and "N" of the mains connection of the controller or of the burner control unit swapped Combustion values not optimal.
How do I fix fault code F A7 on a Viessmann boiler?
First check the cause described above. Then restart the appliance using the reset button. If the message comes back, a part usually needs replacing or the fault needs to be repaired by a qualified professional.
Which parts do I need for Viessmann fault code F A7?
That depends on the exact cause. In the Viessmann parts overview at Instalpunt you will find the current price and stock for each part.
Can I fix fault code F A7 myself?
You can reset the appliance and check things like the water pressure or settings yourself. Work on gas-carrying parts must be left to a certified gas engineer.
All Viessmann boiler faults and codes at a glance →