Baxi 105 e - Hot water is also warming radiators

[AndyJay2019]

Hi all.
We've had this problem for some time now.
I have changed the diaphragm on a couple of occasions, the last time being about 2/3 years ago.
When we turn the hot taps or shower on, the radiators get warm too, taking away some of the heat from the hot taps or shower.
This happens when the heating is not on and the heating timer is off.
I can change the diaphragm again, but if that doesn't do the trick, what else might it be?
Many Thanks in Advance
Andy

 

[picasso]

Your diverter valve needs serviced or changed.

 

[ianmcd]

Nothing to do with the diaphragm, you need a service kit for the valve

 

[AndyJay2019]

Thanks Guys - I'll take a look at that.
Much Appreciated
Andy

 

[AndyJay2019]

Just to confirm - Is this the service kit I need?

https://www.ebay.co.uk/itm/282395177591

 

[ianmcd]

Yes that is the correct one

 

[AndyJay2019]

Me again....
I have the kit now and going to try to fix it this weekend.
Just to confirm.
Which part of the diverter value is causing the radiators to get warm/hot when the hot taps are running please?
This will help so I don't have to change everything that's in the kit (there's loads of bits)
Many Thanks
Andy

 

[micpwelsh]

 

[micpwelsh]

There's a picture you just need someone to say what each bit does !

 

[gas112]

in the service kit pic you have two large brass bits you need to change the bit you can see with white hole in middle
Then in middle of pic you have two brass spindles with black O rings on them you use the left hand one this goes through the hole on previous bit , its that pin that gets gunged up and causes it to pass to heating when water on and it is only about 1mm of gunge that causes it.

Unlike just changing diaphragm you will have to actually drain boiler to change this bit being very careful not to get water onto the pcb

 

[ianmcd]

I wouldnt recommend using a power driver though

 

[gas112]

two points .
I. he should have mentioned which way up diaphragm goes . easy diy mistake to put in upside down
2. the grub screws joining two section put them in a position you can get to easily when in position .
As for the plastic bearing plate and cone disintegrating this is getting a common problem as some of these are over 20 year old now

 

[ianmcd]

Take pics on your phone of everything you remove as you take them apart , and you will know which way it all goes back together

 

[durhamplumber]

Take pics on your phone of everything you remove as you take them apart , and you will know which way it all goes back together

To original poster And do not even breath on the pcb...let alone get it wet...Baxi specially designed the pcb location to catch any water running from thermistors and various nuts that need to be undone!.

 

[gas112]

To original poster And do not even breath on the pcb...let alone get it wet...Baxi specially designed the pcb location to catch any water running from thermistors and various nuts that need to be undone!.

you can get these boards soaking with usually no ill affects after the hair dryer treatment but not recommended for diyers