Baxi 105e - high pitch noise

[Adam75]

Hi

When the heating is on & someone flushes the toilet the boiler makes a high pitch noise, almost liking singing.

The only way to stop the noise is to either run the hot water tap or open the bleed valve on the pump. Both stop the noise instantly.

About 2 months ago I clean the primary heat exchanger to solve the hot water gong cold, hot, cold etc and cleaned out a lot of crud from the heat exchanger. the hot water works fine now.

I can't quite work out if the noise is coming from the pump or 3-Way Valve Assembly.

Read a few posts but lots of conflicting answers.

The boiler pressure is between 0.8-1.5 bar.

The boiler has also just been serviced!

Does anyone have any ideas how to prevent the noise?

Thanks
Adam

 

[Baxmax]

3 way valve o-rings.

 

[45yearsagasman]

X 2

 

[ianmcd]

X3

Ian

 

[Adam75]

Are all the o rings external, ie the ones connecting to the flow pipes or are there o rings inside the valve?

I did replace the diaphragm earlier the year but decided not to replace the o Rings as I could not get the valve back on on with new o rings. How I wish I changed them now!

 

[ianmcd]

The o rings that you need to replace arent the ones in the diaghphragm assembly that you removed, the part that the diaphphragm assemby connects on to with the two securing screws you have to remove that (tail plate assembly and then remove the assembly inside that and the seals you need to replace are in there, cant remember the part number for the seal kit but if you go into any wolsley part centre and ask for a diverter valve service kit they will have one but they will call your boiler a Baxi Combi 105e

 

[45yearsagasman]

View media item 30316That one is the same as Baxi 105 and has got all the bits you'll need.

 

[ianmcd]

View media item 30316That one is the same as Baxi 105 and has got all the bits you'll need.

Hi Pete forgot that Baxi bought the old Alpha production line, OP good luck fitting this kit the rear nut is an absolute pain in the erse to refit if I remember correctly

 

[Adam75]

I'm sure I got an overhaul kit before but could not get it back on with the new o rings so put the old ones back on!

Thanks

 

[ianmcd]

yes can be a bit of a job getting the rear nut to thread but just persevere and you will get there, only other option is to replace complete valve but they are around the £100 mark last time I bought one I think but was a long time ago

 

[Adam75]

I'm really struggling which o rings to replace. Are the o rings external on the 3 way assembly valve as shown in this picture or inside the valve?

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• Adam75
• 2 Dec 2012
• 1

or are they these ones on the inside/push rod?

Untitled

• Adam75
• 2 Dec 2012
• 1

Untitled

• Adam75
• 2 Dec 2012
• 1

 

[Adam75]

I’m also now experiencing the hot, cold, hot water issue again! I cleaned the primary heat exchanger about a few months ago which resolved this but this issue has come back again! Is this related to the o-rings I need to replace?

I’ve raised another post on this separate issue:

//www.diynot.com/forums/plumbi...water-goes-hot-cold-hot-again.346607/#2595103

Thanks
Adam

 

[Adam75]

Just to close the thread, I've replaced the 2 small o-rings inside the 3 way valve and at last no more singing pipes!

This forum is amazing!

 

[Agile]

Can anyone explain how flushing the WC can have any effect at all on the boiler?

Thats unless the filling loop has been left open or there is some pipework connection between heating and cold supply to the WC, neither of which should be the case.

Tony

 

[gas112]

With Agile on this ,especially saying bleeding pump stops it two completly different circuts same as the 3 way valve O rings.