Balancing steam radiators archived

Interested as well, we are having a similar problem, thinking the dining room where the thermostat is reaches 70 and the boiler shuts off before there's been enough time for hot water to reach the 2nd floor? Have been closing the radiator in the dining room at night which seems to improve the balance somewhat, but curious if there's a real solution. I've been told they should all heat up at the same time...ideally.

There are a few reasons that it could be happening. It could be the thermostat shutting off to soon but most likely it is vent related either on the radiators or the main steam returns.. You should have a plumber come out and take a look to be sure and find the right solution for each of your problems..

Thanks, Phil Masucci

http://www.philtheplumber.net/

This is and has been a personal hobby of mine for years....Love doing this! Here's my opinions and suggestions.

One of the mistakes you can make is having two Large of a Valve relative to the rest of the valves. I found the best results when you use three types, max, all sequential to each other, so there isn't a huge divergence between the largest and smallest (ie a 4,5,6 or a 6,C,D, but not 4,5, D's. Make sense?)

Second, you need to take a small wood door wedge (the kind you use to prop open Doors) and slightly tilt your 'dead' radiators so they are draining properly. Doesn't take much, but Dead radiators are often caused by water not draining out, and clogging the area for the steam to come in (assuming, as I am, you are have one pipe for steam and the return water).

Third, keep in mind that it takes a full week to get your radiator system humming for the winter, so its very hard to make a judjement right now, when they are just getting started. Especially when they are only firing up for a couple hours a day.

One more thing, proximity to your Boiler matters.

I agree with Phil Masucci about the steam returns. I researched this on the web for myself a while ago and found this out about the "MAIN VALVE" and radiator valve settings in general:

Main Vent Valve—Lets air escape from supply main quickly so steam can circulate and reach heating units for fast warmup. Main Vent should be located at least 15" from the last fitting of the supply main. Main vents are the key to good one-pipe steam operation. If you're using good main vents near the ends of every main, steam will travel very quickly to every radiator in the building. If your main vents are working, steam will arrive at each radiator at about the same time.

Vent large radiators quickly and small radiators slowly no matter where they are in the building.

Focus on the air content of the radiator (its size) rather than its location in the building.

A picture is worth a thousand words, so See: http://www.hoffmanspecialty.com/pdf/submittals/hs-901a.pdf
Page 3: "Applications - One-Pipe Systems" the "Dry Return" diagram.

Hope this helps.

Things seem to be improving a bit now that it's a little colder outside (I assume that the boiler is firing for longer, thus the steam is actually getting to the colder rooms before the boiler shuts off), but it's still not completely balanced. We have an MOL-recommended plumber come service the boiler every year, but they never said anything about the "main" valve when I asked them about the balancing issue. How do I know if it's the right size? And I assume we have just one of those? (Thanks for the pic, master-of-none).

Not all systems have, or even need, main vents though as boilers have changed, some homes have benefitted greatly by having them added.