Problem with Vokera mynute 20e blowing fuses.

[JonnyN15]

We have this boiler and a while ago it was failing to start and giving of a loud rattle. I had a look around and the rattle was coming from the pcb...so I bought a new pcb and fitted it.

The rattle was gone and it was trying to start....but now fuses are blowing both on the pcb and once on the actual mains power!

I disconnected the pump and tried it, fuse still blew.

I wired the pump back up and disconnected the pressure switch(two purple wires?) and power goes to everything fine and the fuse doesn't blow. The control unit lights up and works fine ONLY when that is disconnected.

I'm assuming it's got to be the pressure switch. I'm struggling to see how I can change it myself and the exact model I'm after.

This part?

 

[Ray84]

Johnny thats the low pressure switch. Seems really unlikely to be the cause of the blowing fuses as it is just a simple switch, if the water pressures not high enough if wont make, once high enough it makes which puts the boiler into its next sequence of operation to fire.
Once thats proved the fan will run and then in turn the air pressure switch will make,
if your confident enough disconnect the fan wires in the same manner, try again and still see if it prevents the fuse blowing/fan runs with the low pressure switch you were talking about being connected. Sounds like blame might be the fan...however

10028141 is the vokera part number for the low pressure switch (about 20quid), boiler needs to be completly drained down for it to be replaced and it unscrews but id look towards the fan or fan pressure switch to be the cause.

cheers
Ray

 

[JonnyN15]

Ah that's why I've been saying two different kind of switches!

I thought it might not be blowing the fuses simply due to it being the first in a line of components .

Where do I find the fan then?

 

[Ray84]

after looking at some posters im reluctant to say due to people saying u need a gas safe engineer etc etc but

its inside the combustion chamber which is protected by the silver casing above the components you see by 8 screws, just bare in mind by removing the screws your breaking a safety critical seal, fan will be easy accessed once thats removed.
If it proves to be the fan though you'd probably need someone to replace it as its defo not a DIY job but least will make you confident where the fault lies and you may see any obvious causes.

Ray

 

[JonnyN15]

Aye I can do that and at least I can at least have an idea at what it is. Can't afford to pay someone to come in and say it's something else.

I'll disconnect that and see how it goes tomorow.

Wheres the best place to buy parts near Hamilton/Glasgow city centre?

 

[Ray84]

yeah i agree, theres an HRPC (http://www.partscenter.co.uk/parts/index.html) in east kilbride near the old motorola factory and also 1 in hyde park street next to the SECC.

cheaper place is heat spares on helen st, govan.

Fan will probably come in about 100-120quid or 20quid for that low pressure switch but much easier to pay someone to do it as you might endup leaving a fan installation dangerous or the water pressure switch you might endup flooding the boiler, not worth taking the risk i dont think

all the best

Ray

 

[JonnyN15]

Well my uncle who proves to be awkwardly unhelpful is a british gas man....if I find out it is the fan I'll be getting onto him as it's taking the **** now!

I understand you can't say much due to the legalities of it all so thanks very much for the advice mate.

Cheers.

 

[Ray84]

well if it proves to be the fan its a crate of tennants for your uncle

Cheers

 

[JonnyN15]

I took the cover off and I see the fan at the top left of the boiler but it looks like a pain to get it unplugged as the boiler is quite high on the wall. I see the air pressure switch now too.

This raised an eyebrow though

And this is the fan?

 

[nickso]

heat exchanger (or it's connections) has leaked before or is leaking now.

the side panel comes off to access fan connections if need be.

 

[45yearsagasman]

Deleted

 

[JonnyN15]

Well with everything else connected but the fan disconnected the fuses don't blow. Gotta be the fan then?

 

[JonnyN15]

Well since all of this has gone by we have changed the pcb and the fan. Now the boiler sounds like it's firing in the right order but doesn't spark up.

Could this be because we had a new gas box outside the house?

 

[craig51]

Look at your first pic. The valve to the left of the gas has water drip hanging from it.

I wold say you have a leak somewhere inside the boiler, as above, heat exchange, pump, anything really.

 

[rgas]

Nah, that drips from the crap vokera isolation valve, normally weeps just looking at it! Most of time if u gently tap the front of the valve with a hammer (and i mean lightly!) then turn the heating up full, the heat seals it back!! If its stopped lighting since the meter box was fitted, the ecv may of been knocked slightly restricting the gas! If not, id be lookin along the lines of the air pressure switch/gas valve