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Is your Vaillant ecoTEC displaying a boiler fault or error code?

Are you experiencing a fault with your boiler? If so, call our 24 hour UK call centre. Mr Boiler Repairs is the UK’s leading boiler repair and service specialist, providing support for domestic, commercial and residential properties. Our low cost fixed price repair service will provide you with peace of mind and avoid any scary repair bills.

Are you experiencing a fault with your ecoTEC boiler?

Below you’ll find information on the fault codes for your boiler and the possible reasons for the fault you are experiencing.

FO      Flow-NTC open circuit

F1       Return-NTC open circuit

F10     Flow NTC short circuit

F11     Return NTC short circuit

F13     Tank NTC short circuit

F20     Safety temperature limiter by NTC activated

F22     Dry fire

F23     Water shortage, temperature difference between flow and return

F24     Water shortage, temperature rise too quick

F27     Incorrect sensing of flame

F28     Appliance does not start, ignite during start failed

F29     Flame goes off during operation and subsequent

F32     Fan speed variation

F49     eBUS under voltage

F61     Gas-valve control defective

F62     Gas valve shut off delay

F63     EEPROM error

F64     Electroncis/NTC fault

F65     Electronics temperature too high

F67     Flame detector input signal is outside the limits

F70     No valid DSN in display and/or main board

F71     Flow NTC reports constant value

F72     Flow and/or return NTC fault

F75     No pressure rise was detected on turning on the pump

F76     Overheating protection on primary heat exchanger triggered

F77     Condensate pump or feedback of accessories blocks heating

F78     Wrong configuration with 

Con    No communication to the main board

Please note that this information is for guidance only and you seek technical advice.

Here are some things to consider helping repair your Vaillant  ecoTEC boiler.

Built-in filter

In the hydroblock, there’s a white plastic filter. Intended to protect the plate. It would be easier to remove the plate and flush it out than remove the filter. You are able to access this via the sensor housing, you will also need to remove the flow connection from the main heat exchanger.

Faulty pressure sensor

No modified part available. Remove and clean thoroughly. This should be black and not orange.

ecoTEC main heat exchanger

The problems with these are them blocking up. Your heating system needs to be in pristine condition. Engineers state its best to fit a filter on the return. Remove and wash if there is evidence of bits in your system.

Expansion vessel

These vessels are always empty. These can display the F.25 fault code

If you need a Gas Safe service engineer to repair your boiler then book a boiler repair today.


Vaillant Boiler Manuals / Instructions

Download a copy from our library, if your boiler is not listed Contact us and we will do our best to help you.












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