BoilerFaultCodesWhat the manual says
Manufacturer manualActivation of the second diagnostic level
What causes this fault?
This code appears when someone has manually entered the boiler's advanced diagnostic settings by inputting a specific security code. It is not triggered by a mechanical failure or a broken part, but rather indicates that the display is now showing a deeper level of system data usually reserved for technicians. You can usually clear this by simply exiting the menu or waiting for the display to time out back to the main screen.
DIY fix possible
Press the 'Back' or 'Menu' button multiple times to exit the diagnostic screensWait for 15 minutes for the screen to time out and return to the main displaySwitch the boiler off and back on at the fused spur switch to reset the interface
Avoid the next call-out bill
A cover plan would handle faults like D.97: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.
Related fault codes
All 135 fault codes on the ecoTEC pro 24
Seeing a different code? Every code this model can display, in one place.