vaillant blowing my fuse

[steadyon]

Hi to all, my vaillant turbomax plus 824e is really confusing me. i shouldn't be messing around with it but the bloody thing keeps blowing the glass fuse on the right hand side of the pcb as you look down on it. Can anyone help??????????? Cheers!

 

[gas4you]

How far does the boiler get in its start up cycle before fuse blows? I would suspect pump or fan initially

 

[steadyon]

Hi Dave, it blows the fuse as soon as it tries to power up. I have wired the pump up to a 3 amp plug top fuse and that seems to work fine, i have also gone through a prosses of elimination by unplugging all componants and powering up the unit. it doesn't blow the fuse unless the secondery heat exchange unit is plugged in, is there a thermostat or something in there and could this be the problem?

Thanks for taking the time to reply to my first question.

Dave s.

 

[ChrisR]

the secondery heat exchange unit is plugged in,

Sorry, feeling dense but I don't understand... what bit?

 

[steadyon]

sorry, do you mean what bit is the secondary heat exchange? if so its the oblong part just to the left of the pump with 4 pipes coming from it and the top left hand pipe has the flow limiter valve on it.

cheers Dave s.

 

[gas4you]

Do you mean an electrical connection to a DHW ntc/thermistor? If so sounds like it is this. Any water leaks around this? Hard to understand your description of plugging in the secondary heat exchanger

 

[steadyon]

Sorry, i know my discriptions are rubbish. I dont know much about these things, it sounds like its what you said. its an electrical connection coming from the pcb to the front of the component i discribed. there are no water leaks.

 

[gas4you]

For how little they cost I would replace this ntc as a starting point and take it from there. Also check that wires to this are not perished and 'shorting out' somewhere

 

[steadyon]

Thanks for all your help!!!!!!!! much appreciated.

 

[ChrisR]

do you mean what bit is the secondary heat exchange?

No I don't. I think I knew what they are before I'd answered the first 11 posts...

Heat exchangers don't plug in.

If you suspect the temperature sensor, simply unlug that