Vokera linea 28 intermittent fault.

[glenntaf]

Hi
earlier this year I was called to a vokera linea 28 that was cutting out intermittently with no fault code, requiring the customer to reset the boiler to get it to come back on. When I attended site I noticed the pressure gauge fluctuating and slowly rising up to near three bar as it heated up. Checked expansion vessel, nothing in it and would not pump up, changed expansion vessel. All sorted , pressure stable, no complaints from the customer over the summer. However since the colder weather has come and the heating turned on more this cutting out fault has returned. The boiler sits idle until the customer resets it (no fault code, just temperature displayed) then it's fine for a day or 2. It seems clear that the burst expansion vessel was a completely separate fault. Both times I have attended the property I have not been able to make the boiler produce the fault that the customer is describing. Any advice from anyone who has has a similar fault would be appreciated.


Cheers Glenn

 

[shaky]

Have you checked the pump?

 

[diamondgas]

Usual suspect is the ignition PCB, the one that wraps around the gas valve!! Have changed a good few for similar fault 🙂

 

[glenntaf]

Have you checked the pump?

Pumps fine, heating works perfectly while I'm there but surprise surprise after I leave it happens again.

 

[glenntaf]

Usual suspect is the ignition PCB, the one that wraps around the gas valve!! Have changed a good few for similar fault 🙂

Is there a way to check the board? Just struggling to get to the bottom of it when it works perfectly while I'm there?

 

[diamondgas]

Is there a way to check the board? Just struggling to get to the bottom of it when it works perfectly while I'm there?

Not that I'm aware of? However, come to think of it, I've not known there be no fault code and having to "re-set"... It's usually '01' ignition intermittent that I've replaced the board for!

I vaguely remember a boiler sitting in 'time delay' I think it was the Linear? If it is there's a pin on the PCB you can pull/shift... It's been a while to be honest 🙂 I'll see if I have anything to jog the brain cells hanging about 🙂

 

[diamondgas]

Got it!!! ... Jumper 6 on the PCB .... take it out and it removes the pre-heat function. The boiler can 'freeze' in pre-heat as far as I remember.

 

[glenntaf]

Ok at least I have something to go on! I'll keep u posted cheers

 

[diamondgas]

Ok at least I have something to go on! I'll keep u posted cheers

Cheers Glenn ... You can always refit the jumper if it doesn't resolve the problem 🙂