Hydronic Heating Wont Purge Air Out

[simpleman]

Say what no water feeder??? I sure hope it at least has a low water cutoff on it.If not stop right there and offer one or the other infact offer both.


It sure sound like you only have water on the boiler in not in the distribution system..as in no pressure.

I too would have to agree with you if the boiler pressure
was the same as the domestic pressure then the relief valve should open.

It sure sound like to me you have a boiler that has no pressure on it.

Dryfiring a boiler is bad news.I would make it top pritory
to get back over there with a pressure/temp guage and see
what going on.

Lets us know what you find.

[markwolf]

Originally posted by eagle1154
You might also check to see how much water pressure you have in the boiler.You'll need a minimum of 18 pounds to get the water up to the second floor.There is a formula to use on how much water pressure you need to reach 2nd floor,but it escapes me.I usually use a pump to push the water up to the second floor,then when I get good flow,I open the auto-feeder wide open while purging to make sure I got all the air out,then let the auto feeder work until I reach at least 18lbs.

one psi is equal to 28" of water columb,or for a rough estimate one pound for every two foot of piping heigth.12psi would be more than enough for most two story homes I have worked in keeping in mind the baseboard is at floor level.

[markwolf]

hahaha reminds me of a true story.A plumber made repairs to a frozen piping loop & it would not work when he was done.When I got there I asked where the repairs were made?I cut open the pipe & found a slug of bread to stop the water when he soldered.OOPS!

[Collin]

Originally posted by SeattlePioneer
There is no automatic water feed using a regulator and no check valve, just a water stop directly off the domestic water line.

No check valve means the possibility of boiler water getting into your domestic.
Bad, bad, bad.

[clyde1]

Looking for help related to this subject:

I'm trying to get a system my father installed working (~31 yrs ago).

I just sarted up the system after it has sat for the summer. My problem is similar in that the upstairs isn't working (the radiators aren't warming up). I'm not sure if there are truly defined purge points, but I see places I could use.

As I'm studying his work, he does have the supply line going into a pressure regulator going into valves that can be oppened to feed into the system. He does have an expansion chamber in place. He has numerous valves on the supply and return sides. He had converted an old steam/condensation system into a circulating system with an American Standard water/boiler system. He ran copper return lines from all of the radiator lions back to the furnace room. Looking back it's pretty remarkable what he did.

Right now I think there is a little air in the system, because I can hear a little trickling as the water is circulating. I'm not sure which pressure valves are working. But if the one right off the boiler is correct, then I'm only seeing 5 lbs when the boiler is running, and I don't really see any change between when the boiler is running and not running. This boiler is in the basement, so it seems like closer to 16 lbs is what is needed to get to the 2nd floor. Shouldn't I see some increase in the pressure on the output of the boiler when the pump is running? Or is the idea that once the system is purged of air, we just need a small pressure differential between the input and output of the pump to cause some flow through the whole system.

The radiators on the 1st floor are warming up nicely. Regarding purging the system of air, I was thinking of using small, what looks like a steam valve, near the top of the radiators. I was thinking of opening these valves slightly on the 2nd floor while someone in the basement allows a little domestic water to enter the system until I see some water trickle out of these points. I just hope they close tightly when done so not to have a source of air going forward.

The other thing I was thinking about was closing as many valves to the 1st floor radiators as possible in order to force as much flow through the 2nd floor radiators as possible. However, if it is air that is preventing the flow upstairs, and I've got the 1st floor radiators closed, then I'm concerned of having the boiler on when water is not actually flowing.

Anyway, my bottom line question is if the small steam valves at the top of the 2nd floor radiators would make a good purge point? Thanks for your help