viessmann 100 weather comb

[Gasmk1]

went to service a viessmann 100 and install weather comp fitted the lead to x21 as per wired the sensor but the boiler was not seeing the sensor, phoned viessmann and went through it, sensor is correct one 5K the resistance was ok, checked all connections and the were fine anyone else had this problem is it the sensor or new or connection cable (both brand new) or is it the board. viessmann technicaal couldnt help

 

[townfanjon]

Weird one this , defo no breaks in the wire from sensor to board . Test each individually .

 

[Gasmk1]

yes pretty sure all wires ok was getting resistance at all connections,
will do cont check on cable tomorrow

 

[ShaunCorbs]

Did you prog the boiler to say I want to weather comp ?

Have had one where it wanted a restart/ set

 

[Gasmk1]

its the old one with 2 dials not the touch screen.

 

[ShaunCorbs]

its the old one with 2 dials not the touch screen.

Fair enough think it still needs a reset

 

[Gasmk1]

how do you do a reset the viessmann tech didnt advise it

 

[townfanjon]

Heating dial turn clockwise , but hold it there for a few secs otherwise serv mode comes on .

 

[ShaunCorbs]

Think you have to turn both knobs to something best ask tech as I can't remember now

 

[townfanjon]

You would think connecting it up to x21 it would recognise it straight away , what type / size of wire are you using ?