Excessive gas buildup in heating system

Darrell Utley

The hot water heating system in a commercial building ( 4 stories) I manage has produced large amounts of air/gas that contains hydrogen, CO, methane etc. We bleed it off through 4th floor rad air vents.
This problem first surfaced in 2003. We drained the system and operated in 2004 without glycol and subsequently that winter the gas was not as issue nor would it burn. However, 2 suites froze up, hence the reason to add glycol again.
I think our problem is related to ethylene glycol (25% strength) that was pumped in this past summer to provide freeze protection for our tropical Canadian winters. When a flame is put to the air vent when purging the gas, the gas burns.
I discovered this week that the glycol we added may have been in a warehouse since 1994. I am getting independent testing to determine if the glycol is breaking down resulting in formation of the gas.
We have followed all instructions by our chemical treatment supplier and tested the system monthly since 1989. The building is heated with 12 (375,000 btu) SlantFin castiron sectional boilers. 4 have failed since 2001 and been replaced. The bottom of the heat exhangers in the 8 old boilers were badly scaled and we thought the burner flame on the scaled heat exchangers could be forming the gas.
We ran 4 new boilers only in October, 2005 for 2 weeks and 4 old boilers only for 2 weeks. There hasn 't been any noticeable change in the gas formation when we compared the new vs old boilers.
Help! Winter is soon upon us. If the glycol test indicates it has broken down we will be dumping and refilling with water to get us through the winter
Any thoughts on our dilemma.

bigugh_4

HuMMmmmmmmmmm?

"bottom of the heat exhangers in the 8 old boilers were badly scaled and we thought the burner flame on the scaled heat exchangers could be forming the gas."
Glycol is a cousin to alcohol and is flamable if in the correct situations. I'd almost bet your "on the spot" for the gas formation statement above. In your case, there are thermo heating oils that could be used. information from any oil manufacturer could be obtained. Fire codes would have to be addressed, but the cost of boilers and freeze up may be the best bet to try!