performa diverter valve problem

3 Aug 2005
Reaction score
United Kingdom
I have another problem with a potty performa 28i.

The diverter is not operating properly sending heat down the feed pipe even when hot water neon is on.

My question is should I replace the whole valve or just the operating head and replace the CH pressure diff. rubber diaphram?
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I really dont know why you are now talking about the system flow switch when its got nothing to do with your problem.

In any case the system flow switch is required to operate on both DHW and CH.

In all probability the manifold section will now clear its sticking problem now that you have got it to start to move, but not necessarily particularly if there is something jamming it. I once found a broken fuse inside one!

Now what about something interesting like the moose head?

Ok I take your point - I am anovice to boilers but justwanted to check the diaphram in the CH pressure diff to make sure.

When I isolated the boiler from feed and return to drain the system and turned off the mains water, I turned on the hot taps to drain the hot water out but nothing comes out of the taps - none of them all over the house! - Why wont the remining hot water come out is this something to do with the diverter problem

I have tested the boiler to see what is happening today - when on hot water pre heat or tap open most of the heat is going down the CH feed pipe. - Do you recommend I just get a whole new diverter valve assy? I have found one at around £60 - I have checked to see if 230volts are getting to the operating head motor and it is. I can also hear the operating head moving when switching between hot water and central heating.
I now know why the hot water supply has always been poor from this boiler!

As for moose head - I am waiting to see my neighbour - will find out!
how can i test HW microswitch on the diverter? As I have said before it hasnt got any droplets on it. Can i test with mulimeter?

If i remove the microswitch and watch the pin what is the correct sequence of operation when HW is called for?

When you used to refer to gland what did you mean where is this on the switch or differential?
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I wish you would forget about the system flow switch, to repeat its required for both CH and DHW. If you open it you will probably damage it.

Undo the fixing for the actuator motor and let it rest freely. That will be in the DHW position and you will not get any CH or at least you should not! Tell us if you still get heat into the CH. You can push the pin on the diverter to see if it moves about 8 mm freely but its a little too strong to do it without a thimble.

You can test the DHW microswitch with a multimeter, should be over 1,000,000 ohms when in the NO condition. Less that 1 ohm in the closed position.

I am really looking forward to hearing about that moose head. I am asking my friend in France for the name of the auctioneer.

I removed the actuator motor from the diverter and then turned on the HW taps the CH feed pipe got that hot that I couldnt hold my finger on it - the HW outlet pipe on the other hand didnt feel that hot I could hold my finger on it. So does this mean the diverter is stuck solid and needs replacing? Is it a job that a competent novice can do? - Should I get new seals for all joints as well - Is there a set sequence to remove the old one?

I removed the microswitch and was able to push the pin in on the HW pressure diff. it moved freely. The pin comes in and out freely when a tap is opened.

I then checked the DHW microswitch with a multimeter - with the contacts closed it measured 0 ohms and with the switch open the measure ment jumped all over the place the multimeter was on 2000KOhms and measured between 0.6 and 1

Still on the case of the moose head! The auction rooms are still there apparently.

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