# More boiler trouble



## Deejay100six (Nov 24, 2007)

Hi all, first time in this forum, doesn't seem very busy but worth a try.

I have an old Gloworm co-ordinate G gas fire with back boiler and six radiators, i know its seen better days but cant afford to replace just now. My problem started last time i drained the system, not sure why but when refilled i get an airlock in the hot tank, i know its there because if i put the gas boiler on the water gets hot only at the bottom of tank, if i put electric immersion heater on the whole tank gets hot. Trouble is i only know one way to attempt to rectify this, taught me by a dubious plumber, is to temporarily remove the thermocoupling from the back boiler and literally boil the hot water to get rid of airlock. I'm fairly sure this is probably not the way to do it and anyway it didn't seem to work last time.

Can anyone tell me the proper way to do it? :grin:


----------



## speedster123 (Oct 18, 2006)

is this hot water tank external?
you might consider drilling and tapping an 1/8 to 1/2 pipe thread on the top to accommodate an automatic air eliminator..or even a hose bib.


----------



## Deejay100six (Nov 24, 2007)

Yes its a free standing tank in a cupboard upstairs and had been thinking about trying something like that but there must be an easier way. I probably know what a hose bib is but even though we both speak english there are some differences in terminology between our countries, eg, your faucet, my tap. I do however understand imperial, (imo english) measurements as opposed to all that euro rubbish.


----------



## speedster123 (Oct 18, 2006)

hose ****, boiler drain, hose bib
http://www.wetearth.com.au/Product/ProductList.asp?lngSubCatID=47
http://www.keidel.com/mech/pvf/valve-drain.htm
http://www.bellgossett.com/ProductPages/Parts-Automatic-Air-Vents-Nos87-67-7.asp


----------



## Deejay100six (Nov 24, 2007)

Tanks very much Speedster.


----------



## speedster123 (Oct 18, 2006)

> i get an airlock in the hot tank


this isnt a boiler expansion tank? is it?
because if if it is an expansion tank, its normally half filled with air, so the heated water can push up on the air cushion for expansion. you would *not* want to bleed it out, you would want to *drain* it out.

otherwise if this is a domestic hot water tank, you naturally want it filled.


----------



## Deejay100six (Nov 24, 2007)

No, it is a domestic hot water tank.


----------

