Jaguar Boiler 28kW: Hot water only when the tap full open

[rfm]

Hi,

My do-not-know-how-old Jaguar boiler 28kW developed an interesting problem: at first I had to open the taps to almost full to get the boiler started and hot water running. Then, it worked only with the tap in the kitchen downstairs, which is next to the boiler, but not with any taps upstairs. Today I cannot start the boiler even with the tap in the kitchen.

The boiler does not show any error message. I found the pressure to be 2.2 (a few months ago it was closer to 1.0), so I drained some water to bring it to 1.2, but it did not help.

Any ideas what else can be checked or done? It looks like a sensor / switch problem, but which one?

Cheers,

Rafal

 

[45yearsagasman]

Most likely to be the diaphragm in the diverter valve. Thats where I'd start.
You could be a bit more precise on the exact model.

 

[rfm]

Many thanks for the hint. I checked the forums again searching for "diaphragm" and Jaguar and found the thread:

//www.diynot.com/forums/viewtopic.php?t=139939

which seems to describe the same problem and the same boiler. I will order the part and report back if replacing it fixes the issue.