Baxi 105e 60 light flashing

[Daviesmith]

Hi I just noticed that my baxi 105e had stopped working (central heating) , the 60 light was flashing (fault on pump or low pressure).
My water pressure is 1.2 bar .

I reset the boiler and it's now been on for 2 hours so I'm guessing the pump isn't broken.
Any idea what the problem could be ? Thanks

 

[CBW]

Pump could be getting weak, or may have stalled, so in essence, could still be the pump

 

[Daviesmith]

I suppose that would explain why it's starting working again when I reset it .

 

[ianmcd]

There is a pump proving switch on the top of the diverter valve and this contains a diaphragm, there is a small impulse hole below that and it is becoming blocked

 

[Daviesmith]

There is a pump proving switch on the top of the diverter valve and this contains a diaphragm, there is a small impulse hole below that and it is becoming blocked

I can't really see in the hole as the pin never goes completely in . Here's a photo of before and after I turned the heating on today

 

[Daviesmith]

There is a pump proving switch on the top of the diverter valve and this contains a diaphragm, there is a small impulse hole below that and it is becoming blocked

Hi again just re read your reply. I need to take out the small diaphragm to unblock the holes . Can I do this with the valve in situ ?

 

[ianmcd]

Hi again just re read your reply. I need to take out the small diaphragm to unblock the holes . Can I do this with the valve in situ ?

yes but you need to drain the boiler to do it, but by the looks of your pics it is fine , could be the actuall switch that is faulty, best to wait untill the light comes on and have a look at that switch and see if the pin is fully out when the light comes on

 

[Daviesmith]

yes but you need to drain the boiler to do it, but by the looks of your pics it is fine , could be the actuall switch that is faulty, best to wait untill the light comes on and have a look at that switch and see if the pin is fully out when the light comes on

Light came on again and boiler went off . The pin is down now

 

[ianmcd]

The way it works, below that pin is a small diaphragm, when the pump starts it causes a differential in pressure, this pushes the pin up to make the switch and tell the PCB that everything is fine and to fire up, if the pump is running and the system is at the correct pressure and that pin does not come fully out to make the switch then the fault light will come on, if that is the case it will be that small hole that has grit in it

 

[Daviesmith]

Is it possible to leave the valve in the boiler and just remove the four screws micro switch and diaphragm? Then how would I clean the holes ? Something like a pin ?

 

[ianmcd]

Is it possible to leave the valve in the boiler and just remove the four screws micro switch and diaphragm? Then how would I clean the holes ? Something like a pin ?

yes exactly that, but on that boiler make sure you cover the pcb housing with a towel or similar as any water will go straight in there, the way I do them is drain the boiler, remove the 4 screws remove the diaphragm and gentlt poke any crud, the gently opsen the filling loop and you will see loads of grit coming out of th hole, once it runs clear, clean everything and reassemble, obviously check the diaphragm to see if it is stretched or pinholed but I have never had to change one yet , however I always do as I have loads of them on the van

 

[Daviesmith]

Just checking so I obviously drain down the boiler but I can leave the water on ?

 

[ianmcd]

Just checking so I obviously drain down the boiler but I can leave the water on ?

yes no problem the secondary water is on a completely different circuit

 

[Daviesmith]

Thanks Ian , I'm warm again, so far anyway . There was more than a bit of grit in there, I've also changed the diaphragm as it did look baggy. Thanks again

 

[ianmcd]

Thanks Ian , I'm warm again, so far anyway . There was more than a bit of grit in there, I've also changed the diaphragm as it did look baggy. Thanks again

yes Davie that has been the problem, that diaphragm is well worn, and yes it is surprising how much crud comes out, that is why I always do the filling loop trick, it completely clears it