Error message 'Con' on Vaillant ecoTEC plus 937

[damski83]

Hi there!

We have just had a new pump fitted to our Vaillant ecoTEC plus 937 today. The previous pump has been making a series of noises when running to suggest the pump was about to fail.

After installation the boiler was switched on where it displayed a temperature of 70c, followed by 0c and then continued to flash the message 'Con'. At present with this message the boiler is not producing any hot water/heating and there appears to no activity. The combiboiler runs off an LPG tank and feeds the radiators, hot water and underfloor heating on the ground floor.

I've searched through the supporting manuals and online - there's no reference to suggest the cause of this message (though I'm certain it's a simple cause).

If anyone can shed some light on this message it would be appreciated - looks like we're getting set for a cold evening now it's snowing outside d'oh!

Many Thanks!

Adam.

 

[Reg Man]

Turn it off at the mains electrical switch. Ensure all of the air has been bled out of the heat exchanger through the auto air vent. Ensure the system water pressure is set at about 1.5 bar. Then turn it back on at the mains electrical switch. Worth a try for starters. The engineer who changed the pump should have done this. Hope the pump did need changing, and its not something else wrong with it.

 

[Reg Man]

Something else to check as its so cold. Make sure your condensate discharge pipe is not blocked with ice.

 

[garrywhite]

"con" meaning- no communication to main board, cause- connection error display board. I would check all electrical connections around the board. Hope this helps.

 

[PLUMBike]

con No communication with the printed circuit board.
Communication fault between the display and the printed circuit board in the electronics box.
As previously said check for the electrical connections from the pump considering that the boiler worked before the pump was changed.​