No Hartford loop or check valve - add one?

Charles_8

While insulating my main, I discovered that there is neither a Hartford loop, equalizer, or check valve. At least the boiler does have a LWCO and an automatic feeder!

Now that I have proper venting, the lack of proper plumbing became apparent the other day. Normally the pressure doesn't even move the gauge, but during the long firing after I got home (and turned the t-stat up), the vents closed and the pressure built up to about 1.5 psi. At that point either the pressuretrol or the t-stat cut out and it gradually dropped back to zero.

The radiator in the living room gurgled, and even spit some droplets out of its vent, which I've never seen it do before. Apparently some water may have been forced out of the boiler back into the return line (I don't have a gauge at the return so I don't know what the pressure differential around the main was). Automatic feeder didn't kick in though, and the gauge glass only dropped about 1.5" maximum. It's centered in the glass when off.

Anyhow, what should I do to fix this? After reading the wealth of information on this site, it seems that adding a check valve would not be a good idea because sediment and corrosion would eventually clog it. I rarely see any pressure on the gauge so backing up into the return is usually not an issue. With 2" iron pipe mains and about five feet of 1.5" vertical drop to the boiler return, the chances of a break are minimal (and there is a LWCO as mentioned). I figure there are at least four approaches:

0) Do nothing. It's been working for at least 3 years without any water hammer, and the boiler has been there for about 25 years.

1) Make sure the pressure stays low, below the point where the return could possibly flood. (Get a vaporstat to replace the pressuretrol).

2) Add a check valve. Not sure how to annually remove and clean it though.

3) Add an equalizer line.

4) Put in the proper Hartford loop with equalizer.

What do you think?
thanks
Charles

Paul Fredricks_3

There is the possibility that you have a counter flow system. See if there is a return line. If you only have supplies, and an equalizer coming off the header, that's probably what you have. No Hartford Loop needed since there is no return to keep the water from backing into.

If the vents are spitting now it's probably because the mains are insulated now so the steam is getting up to the radiators faster and not letting the condensate out. I've seen this before. Try slowing down the vents on the radiators a bit. This will slow the flow of steam and allow the condensate to get out of the rads and back to the boiler.

Of course, if you have a return, forget all that.

Charles_8

No return line...

I'll try a smaller vent in the living room radiator.

About the equalizer, maybe I didn't describe it in the correct terms?

The head pipe comes out of the top of the boiler about 3 feet straight up, makes an elbow to the 2 1/2" main loop that runs around the basement, (several smaller one-pipe risers to each radiator with 45 degree tees), then a main vent on a long nipple tapped into the last elbow, where it drops straight back down to the boiler input a couple inches above the floor. There is no other pipe between the boiler output and return (i.e. no equalizer).
???
-Charles

Paul Fredricks_3

That sure sounds like no equalizer. Does the pipe that runs around the basement pitch back down toward the boiler return?

Any chance of posting some pictures?

Charles_8

Pictures

I'm not sure this helps though. There is not much room down there to take pictures...

http://i18.tinypic.com/333zh4j.jpg

http://i7.tinypic.com/2cctlz9.jpg

The beginning of the main actually is at about the same height as the far end, but after four or five feet of run, there is a "bump" up about 8". I think they did it that way because there is a beam obstructing it. Anyway there is a gradual descent over the 40 ft. loop thereafter.