Thank you for your suggestions K and G. However whatever is making the boiler behave this way has to account for:-
1. the pilot light is stable if the boiler is off (ie the boiler thermostat turned to OFF and electricity switched off.)
2. I get multiple burns of the boiler to bring water tank...
I have an ancient boiler, Glowworm Space saver 50, with separate hot water tank. The boiler has been very reliable over the last 40 years,
However, lately, I have had to relight the pilot light several times. You are probably thinking that I need a new thermocouple.
But if the boiler is not on...
This is the You Tube link referred to above
and this is the link for the PDF guide
http://resources.kohler.com/plumbing/mira/pdf/p2741-11-mira-88-installation-and-user-guide.pdf
see pages 28 to 33
Well, finally the shower is fixed. I've lost count of how many times the mixer unit was removed and re-installed but on at least 4 occasions once reinstalled there was no cold water flow. This happened even when I had a different plumber in to have a go.
But this last plumber did finally get it...
OK, so sent email to [email protected]. Will see what they say. If they confirm that problem could have been caused by incorrect reassembly of mixer valve will post further.
Plumber came round to fix leak (not from shower head, but from central spindle) using the Mira 88 service pack (936.12). This fixed the leak, but the shower now behaves in a most curious fashion.
With the mixer knob in the COLD position hot water flows but at a low rate. Advancing the knob...
Trawling through the forum over the weekend, I found a couple of posts that seem to describe a similar problem with a space saver 50 that I had experienced. In both cases it was suggested that there was a partial blockage of the pilot burner injector.
This proved to be the problem in the case...
I wonder if anybody has any ideas about the likely cause of a problem that appeared from one day to the next on this boiler. Boiler had been very reliable previously.
I have had a gas-safe plumber round to look at it, but after 3 hours he has not come up with a solution.
Symptoms are that...