Replaced diverter valve and now it's worse

[vinux]

Sime friendly format e boiler.

I have a problem with hot water. It used to take a lot of time until hot water reaches tap and the radiators used to become very hot when running hot water. I have assumed that this was the classic case of faulty diaphragm in the diverter valve so I have replaced the whole diverter valve. But now it's even worse. I get no hot water at all and the radiators become as hot as previously. Any ideas? Help please!

 

[dcawkwell]

Definitely at problem at the diverter valve.

How else would the central heating be getting hot when the hot water is on?

 

[45yearsagasman]

If the rads are still heating when on hot water then the valve is stuck with the ch port open either by a faulty valve or by a mistake during installation of the valve.
A split diaphragm will not cause the heating to work on hot water demand, it will stop the hot water working. What causes your symptoms is siezed internals of the valve.

 

[Agile]

If the boiler fires up on a DHW demand then the diaphragm section is working and moving corectly so that the reduced diameter part of the shaft is activating the clip on switch.

If the system flow then goes to the rads then the manifold section is not moving to follow the diaphragm section.

The manifold section has a spring that pushes it forward. In the rest position the stronger spring in the diaphragm section keeps the manifold section in its rest position.

Did you really buy a proper genuine brand new diverter valve?

Was the water in the boiler really black and dirty? Perhaps the manifold section has become jammed by the dirt?

Tony Glazier

 

[vinux]

If the boiler fires up on a DHW demand then the diaphragm section is working and moving corectly so that the reduced diameter part of the shaft is activating the clip on switch.

Yes, I can see the clip coming out of the diaphragm section when I open the tap.

If the system flow then goes to the rads then the manifold section is not moving to follow the diaphragm section.

The manifold section has a spring that pushes it forward. In the rest position the stronger spring in the diaphragm section keeps the manifold section in its rest position.

I thought that the manifold section pushes the diaphragm section. Am I wrong or missing something here?

Did you really buy a proper genuine brand new diverter valve?

I would think so. It did say "genuine replacement part" and it looks 100% identical.

Was the water in the boiler really black and dirty? Perhaps the manifold section has become jammed by the dirt?

The water wasn't dark and didn't contain any mud or anything.

After my last post I thought that maybe the new diverter valve was faulty so I swapped it for the old diverter valve but with the diaphragm from the new one. And it's the same.

I have read somewhere that this may be caused by clogged up DHW heat exchanger. Could this be the case? Maybe the debris or dirt moved in the HE from flipping it too many times whiles trying to remove the whole thing.