No Hot Water....

[conny]

Hi all, I've posted about this problem before and it seemed to be sorted but now its happening again.
I have a Jaguar Combi and the water only heats up when the CH is on. I've been told it could be;
A/ The diverter valve.
B/ The heat exchanger.
C/ The micro switch sticking.
D/ The thermistor.

I've checked the thermistor with a multi meter and get differing readings when it is cold/warm/hot so assume this is ok.
Can anyone point to the other parts in the following photos, (sorry they are so large), in the hope there is some way I can check them without getting in too deep. I will not be taking anything apart unless it is simply a matter of undoing a screw to check the micro switch etc.

Should add, after the heating has been turned off for about ½ hr I can still get hot water but much longer than this and the boiler doesn't ignite.

Thanks lads.

 

[DP]

I would be looking at the big thing below the left hand copper pipe (the unit in the picture, made from brass with three steel screws).

Why is tape applied to the right of this manifold?

 

[conny]

I believe thats the Diverter Valve. The denzo tape is stopping a slight drip from a couple of years ago when the water board had to replace the diaphragm. They had dug the main supply up and not told anyone when they were about to turn it back on. Consequently there were a number of houses up and down the road who suffered damaged boilers in one way or another. Ours turned out to be a split diaphragm.

 

[45yearsagasman]

1st of all the leak should be repaired(may be causing the push rods to sieze)May be all of what you listed,but more importantly the person who removed the combustion cover I hope is a pro gas man.Nuff said.

 

[conny]

Point taken and will get a Gassafe man in to sort it.