Vokera Linea Max Problem - help

[Foodface]

Hello all,

Did a boiler service on the Vokera Linea Max yesterday, as I was there I noticed the boiler had a fault on it. The DHW was working fine, but when you run the the CH the boiler will either run for a short while (like 10 seconds) then cut out or just go to lock out. The problem is by all accounts from the customer "intermittent but increasingly persistent", but settles down when they "fiddle" with the mode selector switch. While I was investigating I noticed that the boiler was also trying to fire up when in DHW only mode every now and then.

From what I can gather from fault finding I think it's one of the following;

a. Mode selector switch is faulty
b. Faulty ignition box
c. or everyone's favourite the PCB

I've read about these boilers on the threads and they seem like a crock of the preverbial, just wondering whether anyone has encountered anything similar or what people think to the above diagnoses, as I'm reluctant to get involved as the boiler appears to have a mind of it's own.

Thanks in advance

Foodface.

 

[aggis]

If the boiler goes to lock out it'll display an error code.
The boiler has a pre heat for dhw so will fire up when on stand by.
There are visual & electrical checks to do before changing the main pcb or ignition pcb, it's not often main pcb
Post it on the closed Gas Safe plumbers site for more technical help.