baxi 80e tripping the electric when turned on

[lordloren]

Hi I have a baxi 80e, I had a leak from the top of the pump which I replaced thanks to reading these forums, However it must of been leaking for sometime, I fitted the new part, dryed the boiler out for 2 days, but the boiler is still tripping the house fuse board eveytime I turn boiler on.

It was tripping before I changed the part.

Thanks in advance for any help

 

[nessuno]

Hi lordloren, I hope you solved your problem. In UK it seem that gas boiler vendors are obliged to disclose the servicing manual. that's great. I've got the Savio Biasi servicing manual to fix it that I could'nt have in Italy.
I've just got the Baxi 80E servicing manual at http://www.partsarena.com/baxi/System/DATA/Dx/DS1/installation/2288/I05-2288/I05-2288.htm
I find the section "Fault finding" very useful: from the wiring diagram you could be able to disconnect all the parts and then re-connect one after one.
Bye

 

[lordloren]

Hi, Thanks, I have the fault finding manual, but as soon as the boiler is switched on fuses the main board, so I cant really get any further than that, before I buy a new pcb I was wondering if there is any thing else I can try,

 

[lordloren]

update.... it seems the boiler would stay on if it was selected to hot water only.... but if I am to open a tap and call for hot water the boiler would trip

I have narrowed it down to the pump, on closer inspection the large white capacitor inside the black housing on the pump has been getting hot and slightly melted and split, there is also a smell of hot plastic and burn smell inside the black box, I wondering now, if I can locate one of these large capacitors? would the function of the pump be restored ?

its a grundfos pump

Thanks loren

 

[nessuno]

Hi, are some of the last 3 neons right on the front panel command on?
they should report the fault on the pump, on the Hot Water sensor and on the central heating acoording the manual and the signs close.
How long the boler was operational? frequently the 3 way diverter valve stucks because of scale deposit. If the case, there are troubles in switching from heating to DHW and the pump can be stressed.
For what I understand you have just replaced the pum. please check the connections to the capacitors, too.
Regards

 

[ROSSGR]

Check out the moulded plug which feeds the pump, most likely that has melter internally and is shorting. Bet Ya it is that

 

[nessuno]

My Grunndfoss pump is type UPS 15-60 AO 130 220-240 VAC with a venting valve on top as in the Baxi. The capacitor in the connection box is 2.5 microF and the value is reported also in the pump nameplate. The capacitor is needed to have the pump motor started. I agree with ROSSGR to check the plug in the box. It could be melted because of loose wiring connection. A US Navvy Manual suggests to screw and tight the wires the first time, then wait some minutes and tight again. However i'm afraid that the the original trouble wasn't with the pump because of experiences I had. In my case, i) the leaks from the top of the pump was due to droplets flowing out from the pump venting valve: I unscrewed cautiously the screw on the valve and I cleaned it; ii) a fault to ground tripped 4 times the differential switch (life safe guard switch) in the house switch board before uncovering it was the boiler and in the boiler one component, the motor head of a 3-way valve. Hope you succeed.

 

[lordloren]

Hi Thanks for your replies. . I have replaced the top part of the pump and all ok now, saves buying a new pump (£80 odd ) plus the messing round with replacing the full pump, I changed only the top part of the pump and it was easy, 4 screws ! although I have just bought a complete pump off ebay for £12 including postage as a spare, Yes the leak from the air vent on the pump will have cause the problem in the first place, that was replaced first... I will check the plug in the box that feeds the pump tho that could be loose connection thanks for that rossgr might save this second pump from malfunctioning. A lot of satisfaction in repairing the boiler myself with the help of u boiler gurus,
Thanks again Loren