Alpha 280E wont heat dhw

[sparkatan]

Strange this, when we turn on hot water in the bathroom the boiler fires up and produces hot water, albeit a lot slower than it used to, however,when we turn on the kitchen tap the boiler won't fire up. If we leave the kitchen tap running then turn on the bathroom tap, then we get hot water in the kitchen.

Any ideas anyone?

 

[Agile]

Dop nyou ever get the boiler serviced?

Nevertheless the diverter valve seems to be faulty.

Tony

 

[sparkatan]

Dop nyou ever get the boiler serviced?

Nevertheless the diverter valve seems to be faulty.

Tony

Today i stripped the diverter valve and all is ok, I replaced the internals about 2 years ago.
The only thing I found is a torn diaphragm which i will replace when i can get one.
I temporarily rebuilt the valve and ran the boiler, holding the diaphragm micro switch in and switched on the hot tap. No hot water. It seems the boiler water is bypassing the H/W heat exchanger. Isn't the diaphragm just a signal to bring on the boiler or does it activate the diverter?

 

[Pascal34]

The torn diaphragm wil be the initial fault and now because you've taken the diaphragm out there is nothing to move the diverter to heat the dhw heat exchanger, Once you put the new diaphragm in all should be well.

 

[Agile]

The main purpose of the diverter is to divert the heat from the rads to the plate HE.

A secondary purpose is to tell the boiler that there is a demand for DHW so the boiler can turn on if the heating is off and to control the temperature in accordance with the DHW control knob.

Tony

 

[45yearsagasman]

When you say you replaced the internals, what did you replace exactly?