More boiler trouble

**deejay100six** · 02-20-2008, 07:03 PM

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?

**speedster123** · 02-21-2008, 05:22 AM

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** · 02-21-2008, 08:34 AM

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** · 02-21-2008, 09:11 AM

hose ****, boiler drain, hose bib
http://www.wetearth.com.au/Product/P...lngSubCatID=47
http://www.keidel.com/mech/pvf/valve-drain.htm
http://www.bellgossett.com/ProductPa...Nos87-67-7.asp

**deejay100six** · 02-21-2008, 12:41 PM

Tanks very much Speedster.

**speedster123** · 02-23-2008, 11:14 AM

Quote:

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** · 02-23-2008, 09:17 PM

No, it is a domestic hot water tank.

02-20-2008, 07:03 PM	#1 (permalink)
deejay100six TSF Enthusiast Join Date: Nov 2007 Location: Doncaster, England. Posts: 774 OS: win xp pro sp2 My System	More boiler trouble 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? __________________ A stranger is only a friend you have yet to meet. Everything will be ok in the end........If its not ok, its not the end.....

02-21-2008, 05:22 AM	#2 (permalink)
speedster123 Mentor Join Date: Oct 2006 Location: United States-New York Posts: 3,804 OS: xp pro My System	Re: More boiler trouble 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. __________________ Infection Detection and Removal Thermal Grease Instructions Bench Test Last edited by speedster123 : 02-21-2008 at 05:24 AM.

02-21-2008, 08:34 AM	#3 (permalink)
deejay100six TSF Enthusiast Join Date: Nov 2007 Location: Doncaster, England. Posts: 774 OS: win xp pro sp2 My System	Re: More boiler trouble 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. __________________ A stranger is only a friend you have yet to meet. Everything will be ok in the end........If its not ok, its not the end.....

02-21-2008, 09:11 AM	#4 (permalink)
speedster123 Mentor Join Date: Oct 2006 Location: United States-New York Posts: 3,804 OS: xp pro My System	Re: More boiler trouble hose **, boiler drain, hose bib http://www.wetearth.com.au/Product/P...lngSubCatID=47 http://www.keidel.com/mech/pvf/valve-drain.htm http://www.bellgossett.com/ProductPa...Nos87-67-7.asp __________________ Infection Detection and Removal Thermal Grease Instructions Bench Test** Last edited by speedster123 : 02-21-2008 at 09:17 AM.

02-21-2008, 12:41 PM	#5 (permalink)
deejay100six TSF Enthusiast Join Date: Nov 2007 Location: Doncaster, England. Posts: 774 OS: win xp pro sp2 My System	Re: More boiler trouble Tanks very much Speedster. __________________ A stranger is only a friend you have yet to meet. Everything will be ok in the end........If its not ok, its not the end.....

02-23-2008, 09:17 PM	#7 (permalink)
deejay100six TSF Enthusiast Join Date: Nov 2007 Location: Doncaster, England. Posts: 774 OS: win xp pro sp2 My System	Re: More boiler trouble No, it is a domestic hot water tank. __________________ A stranger is only a friend you have yet to meet. Everything will be ok in the end........If its not ok, its not the end.....