Vaillant fault code Err
Fault code Err on a Vaillant boiler (including ecoFIT pro and ecoTEC exclusive) means: Interface communication. Reset the appliance once. If the code comes back, a part is usually faulty. 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 Err on a Vaillant boiler indicates: Interface communication.
Applies to
Vaillant ecoFIT pro, ecoTEC exclusive, ecoTEC plus, ecoTEC pure, VHR 18-24/7-2, VHR 18-24/7-2 EXP, VHR 20/26 CS/1-5, VHR 23-28/7-2, VHR 23-28/7-2 EXP, VHR 25/36 CF/1-7, VHR 28-34/7-2, VHR 34/43 CF/1-7.
Matching parts
Vaillant parts are available from Instalpunt; shipping to EU countries from €17.95 (€24.95 for more distant countries), usually 3–5 working days.
Parts by Vaillant series: ecoTEC plus · ecoTEC pro.
This message does not point directly to one faulty part. These are the parts that most often fit this appliance:
- Vaillant pressure sensor VHR18-22/3C24-28/3C VHR CW3 4/3 for ecoTEC plus and ecoTEC pro etc. € 24.18
- Vaillant NTC sensor flow/return VHR18-22/3C24-28/3C for ecoTEC plus and ecoTEC pro etc. € 16.99
- Vaillant display cable for ecoTEC plus and ecoTEC pro etc. € 9.15
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 Vaillant boiler fault code Err mean?
Interface communication.
How do I fix fault code Err on a Vaillant 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 Vaillant fault code Err?
That depends on the exact cause. In the Vaillant parts overview at Instalpunt you will find the current price and stock for each part.
Can I fix fault code Err 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 Vaillant boiler faults and codes at a glance →