Baxi Solo 3

Depends how competent you are. You should find a diagnostic chart on the back of the removeable panel at the bottom of the boiler. Work through that to see where it leads you. It sounds as if the pressure switch may have failed. This detects that the fan is running, and stops the boiler firing if it isn't. make sure that the pipes and electrical connections going to the pressure switch are ok. But see where the diagnostic chart leads you - it will tell you how to interpret the little LED indicator lights.

In message , Andy Pandy writes

Probably faulty air pressure switch or knacked pcb.

Is the ignition neon coming on, can you hear the spark (a ticking at about one second intervals)

If so, then either the pcb or pilot valve

Thanks Guys

When I got up this morning the electricity was off.

I reset the trip and it went straight off again.

I turned FCU to boiler off and elecricity stays on.

It seems the problem got worsr over night!

At least yesyerday I could get 2 lights on and no electricity trip.

Geoff

I can hear nothing (could not yesterday before triping started anyway)

Set Square

Thanks I have took the cover off an will look at diagram. I also downloaded a nice pdf file for Baxi maintenance just now so will look at that.

Wow it gets better

I have taken the front cover off and have removed contol panel and have eased the PCB out.

Every time i have been turning power on at FCU then the power has tripped in the house. (only since this morning)

I have checked on price PCB ( one or two places, new and reconditioned)

I have checked all wires and pipes to the pressure switch.

My situation is now this. i do not know for sure that it is the PCB so have tried one or two things to eliminate the fcu , clock, etc (easy stuff but none the less).

I now arrive at this.

I have taken the plug connector out of the PCB that takes a live , neutral and earth to the pump (so totaly isolating pump) and now when I put FCU on at switch, the electricity does not trip at the consumer unit. When I then turn the control knob the same lights as before come on ie Boiler light and Fan light (though as i stand on a chair and look at the fan it is not turning!)

So im back to my original position as my first post only yesterday i was at this position without the need to isolate the pump to maintain electricity to the house.

Is this indicative of a pump problem that got worse over night ?

Is ther a test for the pump that I may do (maybe plug into socket on ring (L,N,E and see if consumer trips or pump works?)

is there a way to test the PCB without actually buying another one.

Realy appreciate sugestions

thanks Andy

Hi Guys

Sorry to be a pain but I must post this.

I was concrned as i read my last post

Fan not running but light on!

So i turned boiler aon and as the Fan On Light illuminated I saw the fan turn a smidge but was obviously struggling. i turned all power off and manually turned the fan,, it is really stiff and screeches.

Wow it seems that this is the problem but why is the connection of the pump now tripping the house electricity?

Shall i take it out and wd40 or greese or should I replace?

In my first post I thought that the fan was on simply because the light said so ,, but now as I have took cover off i can see the fan not turning.

Andy

There is if you have a length of 3 core flex and a plug with 3 amp fuse. It would be better to test the insulation with a megger but if you haven't got one

If the pump is your problem you might not need to

Sounds like the 'fan on' light simply means that power is being supplied to the fan. There is probably another light which comes on when the pressure switch switches - indicating that the fan is *really* running.

I've not had too much success reviving stuck fans - leave it to the experts like Geoff, and get one of his re-conditioned units.

To answer the question in your previous post, you can test the pump by putting a 13A plug on its cable (with a 3A fuse in!) and plugging it into the ring main. If it's ok, have a close look at the connections in the boiler - you might just have disturbed something and caused a short in the pump department.

In message , Andy Pandy writes

Yes, I misread that last night as fan running

... new one on it's way !

Thank you all

Watch this space!

Next episode tomorrow night.

Andy

Well

New Fan installed and boiler fires up fine. Brilliant.

Only prob now is that when I connect the pump to the PCB the Consumer unit trips still !

Could the fan becoming stiff (in the first instance a couple of days ago) and so not working have somehow put load on the pump or PCB as it was struggling to rotate.

I will test Pump tomorrow with a flex to socket on the ring!!

Fan is excellent Geoff thanks, but stay by the phone.

Andy

In message , Andy Pandy writes

Water in the pump electrics ? Take the cover off and have a look

No, they're both powered directly via relays on the pcb

And I bet it'll trip it out

No water found

Yes it did as soon as I connected to the ring.

I fitted a new pump today and all (fingers crossed) seems fine.

Thanks Geoff

Old fan will be send on Monday.

Andy

In message , Andy Pandy writes

Not easily, I have a test rig which simulates the inputs and outputs.

You need to simulate the temp sensor, the APS, etc and have some means of simulating the flame sensing. Just not worth it for £30, delivery and VAT

You would be better testing the disconnected pump with a Megger. Pumps are notorious for suffering leakage into the terminal box or even worse into the windings. Worth keeping in mind that its often possible to change just the "top" of the pump without removing the volute casing. IIRC there is a "universal" replacement pump top produced by Ideal