Baxi Solo 2 Fault Assistance

[Aragorn84]

Ok theres a number of points here so bear with me.

The boiler was installed by the council a number of years ago but the property is privately owned now. Just before we baught the place the council service engineer who was out servicing it said that the bypass pipe was in the wrong place, causing the boiler to "kettle". They never fixed it though, and the pipe is still there.

Looking at the boiler the outlet pipe runs from the boiler down to the pump, then into two 2port motorised valves. About a foot BEFORE the pump there is a pipe which links the outlet pipe with the inlet, via what looks like a stopcock. From what i gather this pipe should be after the pump to allow the pump run on to work properly

Now to the problem, at the weekend my dad reports that the boiler started making lots of banging and clanking noises, (its always banged when the hot water motorised valve closes, but the water was on at this point) It continued for a few minutes until he clicked the hot water off at the timer, at which point it stopped.

He left it overnight and tried to turn it on again, and this time, no banging but the control panel went off completely

I had a look last night and discovered the 3A supply fuse at the switch in the boiler had blown. I replaced this and the control panel came back on. I switched heating and hotwater on at the controls and both motorised valves moved to the open position, but the boiler didnt fire. The boiler on lamp illuminated but nothing more. The pump didnt run either so looking at the fault finding chart on the boilers cover i checked the fuse on the PCB, which had also blown.

I'm going to head to maplin after work today to get another fuse for the PCB, but i'd like some pointers on what may be going on here..

I have guessed that the pump may have siezed or failed, causing the noise and excessive current draw which has blown the fuse. Does this sound plausible?

I'd like some advice on this and what to do with the bypass pipe if you could be of assistance that would be great!

Cheers

Kevin

 

[assured heating]

probably the pump as you say

 

[gas_man_gaz]

could of also tripped the overheat stat if it has got one fitted

 

[gas4you]

Remove the wires to the pump from the terminal block. This will confirm whether it is the pump blowing the pcb fuse, which is a very common fault.

 

[Aragorn84]

ok did some more investigating tonight, i replaced the fuse and it blew instantly, so i replaced it again and disconnected the pump, the boiler fired up just fine.

So i connected a plug to the pump wiring and plugged it in, it blew the fuse in the plug with a pop.... So i guess the pump is dead then

Is this an easy DIY swap? It looks like there is a stopcock immediately above and below the pump so i guess i can just close these and unbolt the pump?

Are they a standard fitting or will i have to do a like for like replacement?

What about bleeding the system afterwards?

cheers!

Kevin

 

[Aragorn84]

I dont like bumping my own threads but i'd like some advice on this before i attempt to fit the new pump!

It seems that the pump has stop valves fitted above and below it, which means i should just have to shut those and fit the new pump.

I'm not sure what i need to do in the way of bleeding it afterwards though?

Also i'd like some advice on this bypass pipe, as i said in the initial post the boiler has a pipe fitted between the inlet and return pipes but its fitted before the pump, this means that when the pump over-run happens the pumps left pumping against two closed zone valves.

I presume i need to remove this bypass pipe thats fitted at the moment and install a new one after the pump, but ive heard discussion of an ABV which should be used. Can anyone tell me what this is or point me towards some information about it!

Thanks

Kevin