Zehnder fault code A0
Fault code A0 on an Zehnder MVHR unit (including WHR) means: NTC sensor Tge is defective (= outdoor air temperature for the ground heat exchanger). Reset the appliance once. If the code comes back, a part is usually faulty, often a temperature sensor. You can check the water pressure and settings yourself; leave work on gas-carrying parts to a certified gas engineer.
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 A0 on an Zehnder MVHR unit indicates: NTC sensor Tge is defective (= outdoor air temperature for the ground heat exchanger).
Applies to
Zehnder WHR, 930 Basic, 930 Luxe, 950 Luxe, 960 Luxe.
Matching parts
Zehnder parts are available from Instalpunt; shipping to EU countries from €17.95 (€24.95 for more distant countries), usually 3–5 working days.
For fault code A0, the part involved is usually in the category: heat exchanger.
Based on the cause, these original Zehnder parts fit (always check the type number of your appliance):
- Zehnder sensor bypass/heater € 39.20
- Zehnder sensor WHR 950 fan € 27.44
- Zehnder sensor WHR 950 Byp € 52.27
Further reading on this cause
Other Zehnder codes with the same cause
- A1 — NTC sensor T1 is defective. (= Outdoor air temperature) Green connector.
- A10 — NTC sensor Tch is defective (= temperature in the cooker hood).
- A11 — NTC sensor Tah is defective (= temperature of the post-heater).
- A2 — NTC sensor T2 is defective. (= Supply air temperature) Yellow connector.
- A3 — NTC sensor T3 is defective. (= Return air temperature) Green connector.
- A4 — NTC sensor T4 is defective. (= Extract air temperature) Yellow connector.
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 Zehnder MVHR unit fault code A0 mean?
NTC sensor Tge is defective (= outdoor air temperature for the ground heat exchanger).
How do I fix fault code A0 on an Zehnder MVHR unit?
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 Zehnder fault code A0?
That depends on the exact cause. In the Zehnder parts overview at Instalpunt you will find the current price and stock for each part.
Can I fix fault code A0 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 Zehnder MVHR unit faults and codes at a glance →