potty puma 80 combi

[hav it]

Went to a job friday tennant keeps getting fluctuating hot water temp. The wax diverter was changed a few days ago but its not made a difference. The central heating flow pipe still gets hot when the hot tap is run.
any ideas chap

 

[ChrisR]

Was just the waxy bit changed or the whole lump including the DV?
Worth checking the temp sensor.
Does it modulate OK?
Hard water> scaled hex?

 

[hav it]

The whole valve was changed, I would of changed the temp sensors but the ch flow pipe gets hot???

 

[ChrisR]

Errmmm...

 

[Agile]

Was this a brand new manufacturer's valve???

It sounds as if it is not working!

I assume there is no external pump anywhere on the heating circuit???

Sounds a very odd situation to me!

Tony

 

[hav it]

problem is i dont know whats been messed with before i got there.

 

[hav it]

going there tomorrow going to start at the beginning and get the dam thing set up right. .

 

[Agile]

Was this a brand new manufacturer's diverter valve???

Tony

 

[hav it]

yes m8t potterton stamp on side.

 

[ChrisR]

You mean it passes to CH while the tap's running, not just on overrun?
HW flow switch working OK?

If you remove the head (allen screws) from the DV in situ, you can remove the internal parts and prod the rearmost disc against its spring, which is what's apparently letting-by. Check it's seating properly etc..?

 

[Agile]

Its difficult for me to guess why a new diverter should not function in the DHW mode.

I could understand it not moving to the CH position if the wax stat was not opening but that alleged fault implies the wax stat is stuck open!

OR

The DHW flow is reversed but that would not operate the DHW flow switch!

We need to know if the boiler senses a DHW flow, red light on PCB etc.

Tony

 

[Gasguru]

Perhaps the pin on the rear end of the central piece is not fully located in the hole of the rear disc.

I borrowed your pic Chris

 

[ChrisR]

It could simply be some muck on the disc on the far left - as I said above!!

...and as can clearly be envisaged from the picture below...

This one does not have a © symbol so you may copy it