Vaillant eco tec screen goes blank then resets after turning off for 5 minutes.

[top banana]

Hi guys, I have a Vaillant eco tec pro 28.
Had an issue about a week ago when screen went blank.
I checked 3 amp fuse at switch.
That’s ok.
I checked internal fuse and used a multi meter to check connections. All seems good.
After leaving off for 15 minutes or so I tried again and the boiler screen came on and the boiler tried to go through its preignition but shut off after 20 seconds or so.
I noted some crustacean on the AAV which is above the pump, so I thought to check the pump.
I vented the pump. A fair amount of water was coming out . I rotated the shaft which was easy to do. The shaft could also be pushed in very slightly and on release comes back.
I then re pressured slightly.
Tried boiler but screen went blank again then waited 5 minutes and tried again and it worked till today when I have the same issue again.
This time no success at relighting.
Has anyone seen this before please.

 

[CBW]

Sounds like you have the circa 2012 upwards model, whereby the pcb starts to fail.

 

[top banana]

Thanks for your reply.
I was hoping for a cunning fix.
I have managed to get it going though it might be a coincidence.
When the boiler started making noises, I vented the pump , just slightly. Fan kicked in, pump was sounding , and ignition occurred.
I have a refurbished pcb on order though I won’t get here till after new year so hoping it will last until then
The place for PCB s seems to be Newcastle , on my search engine anyway.!

 

[top banana]

Boiler failed again.
I have received a pcb in the post, I have installed it and I’m hoping for the best.
On the pcb install videos I watched, the symptoms were the same as I was having.