GlowWorm Swiftflow 100/120, pressure and pilot problems

[Blue_Straggler]

Hello all. I hope I am posting in the appropriate forum.
To the point.
I have a GlowWorm Swiftflow Combi Boiler, accoding to the schematic it's a 100 or 120. It's probably about 10 years old. I've been in this house with this boiler for 2 years, no problem
No hot water from taps tonight so I looked at the boiler, the pilot was out, I relit it.
The gas control valve is an S.I.T. type. The instructions on the boiler door say that I should rotate the valve control knob to the "main burner" position. I am not sure if this is clockwise or anticlockwise from the central position that you use for relighting the pilot; in any case, turning the knob causes the pilot to go out (maybe it's actually a Honeywell valve with an S.I.T. knob?)
So i took to leaving it in the central position, this at least keeps the pilot lit.
The pressure reading on the gauge is 0.5 bar which is probably too low. If I turn on a hot tap the boiler will try to kick into action and the pressure increases to about 0.8 bar.
I've tried different combinations e.g. relight pilot then turn control valve knob one way and the other way; wait 30 minutes after relighting pilort, before testing the water....etc. No joy.
Now the pilot won't stay lit.
Any tips? (Sorry for rambling, it's 1.55am though!)

Thanks
Blue Straggler
__________________________________
lynda, moderator.

moved as posted in wrong forum (appliances)

 

[bster]

recharge to the correct pressure stated in the manual.

 

[Blue_Straggler]

thanks, sorry not been back to the forums. other investigations do suggest that it is merely a case of low system pressure. HOWEVER. I don't have the manual for the boiler and failed to find it online. I am not sure which valve or tap to turn to increase the input pressure. I uploaded some pics in the hope that someone can help...
http://geocities.com/kenny_xray/GlowWorm/

view1.jpg shows a red tap, this turns about 1/8 of a rotation then becomes very stiff. I didn't want to force it.

view2.jpg show the other "controls" a bit more clearly. You can see a silver-coloured connector with a screw-type washer thing, I loosened this screw and loosened it some more until it came off. No change in pressure; I replaced it. Finally the black plastic "tap" at the left. This will not budge easily. Again I didn't want to force anything. Could this be the one though?!

instructions.jpg is just a photo of the pilot-relighting instructions inside the door

 

[Blue_Straggler]

"Finally the black plastic "tap" at the left. This will not budge easily. Again I didn't want to force anything. Could this be the one though?! "

It was indeed that one. It was stiff but I found some inner strength and courage Turned about 1/8 of a rev anticlockwise, pressure increased steadily, then I closed it again, pressure stayed at a healthy-looking 1.4 bar, relit the pilot, turned the SIT valve anticlockwise (I'd been thinking it went clockwise but this always tended just to shut off the pilot!) and hey presto, hot water again. Hurrah. And more "instant" than before - guess that boiler was always running on too-low pressure but I got away with it till last week.

 

[Blue_Straggler]

Balls, it's gone again, and not apparently through lack of pressure, which has actually INCREASED, it's around 1.8 bar. Is that TOO high? The dial goes up to 4 - do I keep increasing it or should I decrease it - and if the latter, how? I only seem to be able to increase pressure using the black tap.

Thanks

 

[fitz1]

main problem with these boilers is the fan. check that it is running smooth.

 

[ollski]

On these horrible things I tend to change thermocouple, overheat stat (wires have caused me probs several times), interrupter.