Setting a vapor stat

leaking

I have a Weil mc lain Lbg 6-23 with honywell Vaporstat, I have it set at 10oz out 5 in, I've been lowering it every day, should I continue to lower it till I don't get heat at the end? It seemed to be more balanced near 16oz out 8 out. Old gas bills are to high, is there much more efficiency in only 3-4 oz? Or do I try to see where it's balanced, I never set a vapor stat and the installer isn't much of help

JStar

Pressure

Go down to 1 ounce if you can. The lower the better. Some of our installed systems run between 0-3 ounces and heat just fine.

Jamie Hall

There's a bit of magic to it...

when you come right down to it.  It really depends -- a lot -- on your whole system and how it behaves.  You need enough pressure to get the steam through the pipes, and that depends on the amount of steam and the size of the pipes.  Then you also need to consider how the venting is done -- the size of your vents and how they are placed on the mains (or crossover traps on the mains) and on the dry returns.



If your venting is adequate, most systems should get even heat or reasonably even heat to all the radiators in the system without the pressure rising to the point where the vapourstat trips.  Then you want the 'stat to trip fairly quickly after that happens.  What is the pressure you are setting?  Ah... that will take a bit of experimenting.



16 ounces seems a bit high, but it may not be -- for your system.  Where you set the differential is actually a bit more flexible -- but I would tend to think in terms of setting it so that the cutin is on the order of 4 ounces of so; less if the system is comfortable with a cutout of less (say 8 ounces -- you might want to drop the cutin to 2 to 3 ounces).



So I guess the short answer is -- set it where you get a reasonable balance to the system, and no higher -- your "try to see where it is balanced".