Worcester 240 Diaphragm change

[Mr M]

I have a Worcester 240 combi boiler and was recently having problems with my hot water temperature being 'cooler' than it used to be. I read up (mainly on here) and the suggestion seemed to be that if my central heating flow pipe was heating-up with the heating off when the hot water was run (which it was), then the likely culprit was a damaged or perished diverter valve diaphragm.

I renewed the diaphragm, which had a small rip in the rubber and the hot water temperature is now a lot better however, the central heating flow pipe still gets very hot when the central heating is not on and the hot water is run.

I have removed the microswitch from the front of the diverter valve and checked that the spindle is moving in and out when hot water is asked for and it does move in and out. I have also had the front off the diverter valve tonight to double check the installation and condition of the new diaphragm and it all looks ok.

Does the fact that the central heating flow pipe heats up when the heating is off and the hot water is run suggest that there is still some problem other than the diaphragm and if there is, what is it likely to be? Are there any checks that I can do to try to determine what is wrong?

Many thanks in advance of any responses

Mr M

 

[Terrywookfit]

The shuttle inside the divertor is fooked

 

[Mr M]

The shuttle inside the divertor is fooked

What's a shuttle? Never heard of that before.

 

[45yearsagasman]

It's a component inside the diverter. Simply put, the internal valve components are not closing the CH port off during HW operation due to seizing up or dirt on valve seats. Easiest way is to replace diverter as a complete part and don't bother trying to repair it.