Vaillant turbomax plus 828e blowing fuse.

[flesi]

Hello guys, I've the same issue with turbomax plus in two different properties. Basically costumers left the boiler off while they been away for few days, they've come back , turned the boiler on and the boiler keeps blowing fuses on the PCB. Has anyone come across this before? Cheers

 

[PAULY1985]

Something's drawing to much power disconnect as much wireing from pcb as possible reconnect one at a time to see whats doing it

 

[flesi]

I've done that, the boiler stays on for probably a minute , tries to fire up then it blows the fuse. Obviously it's short circuit , it's got to be a motor and I think is a fan. I just want a second opinion as the fan it's about £200.

 

[Roger Welton]

Disconnect your suspect from pcb, if fuse doesn't blow eureka.

 

[PAULY1985]

if there's no demand does the boiler still trip?if not how far in the sequence does it get befor tripping

 

[flesi]

Pump runs but the fan doesn't kick on then it blows the fuse. As I said both boilers have been working fine before they've been switched off for couple of days.

 

[Ermintrude]

Just answered own question it's the fan.

 

[flesi]

It baffles me why on both occasions the issue occurs after the boiler has been off for couple of days????

 

[PAULY1985]

Have you tryed checking for voltage at pcb fan conection or at fan it's self befor it trips what about ohms just to be sure

 

[PAULY1985]

When you say off do you meen on stand by or switched off at spur? a sudden serge of power can help things that are on there way out

 

[flesi]

It's 240v going to the fan , haven't check for resistance

 

[Ermintrude]

It's 240v going to the fan , haven't check for resistance

Check aps isn't shorted . I know it's out of sequence but if it's stuck ?!

Boilers normally warm and dry, when off cold damp air comes in, once energised if any of the winding has frayed its a short, coil burns out and it's goodnight Vienna !

 

[PAULY1985]

Volts at fan and its not running I'd say your right, funny it's happened on two boilers at same time

 

[flesi]

Replaced the fan and boiler is working fine!