Excessive water demand

EdS

I have a 2 pipe steam system. The last 2 years I have had to add water far more frequently than previously. No auto feed. Obviously, I suspected a leak but unable to find one. Each summer I have had a gradual return of several gallons of water that I have had to drain off. All radiators have output. How do I find the problem and what do you suspect?

nicholas bonham-carter

missing water

you could check for a leak above the waterline by looking at your chimney, when the boiler is firing. you can sometimes see a plume of white steam coming from the chimney. further than that, you can turn the boiler off, and when it has cooled, add enough water for the waterline to be above the top. let it sit for a few hours, and then look into the combustion chamber for any drips of water leaking out through a rust-hole.

the over-full condition could come from a leaking fill valve, or a hot water coil.--nbc

EdS

Excessive water demand

Thanks. I've checked the chimney multiple times. No steam. The water fill valve does not sound like it is leaking and the summer return is inconsistent. The water level may not change for weeks and then there is obviously more. This is actually the 3 fall. Last summer was different in that the dump all came at once the first firing of the boiler. The level was correct and 15 - 30 minutes later the whole house was banging and the boiler totally filled. I drew almost 4 gallons at once. The other 2 years it has been sporadic during he summer.

crash2009

Pictures please?

Sounds like you are saying that you add water and then it comes back later.  To me this sounds like a slow return or a badly pitched pipe, not a leak.  If I am reading you right, we need more info. 

Can you show us a few pictures of your system?

Do you have any underground returns?

If you are able to post a few pictures, we need to see the boiler and how the steam pipes connect to it, and also a couple pics of the radiators showing how the pipes connect to it.  Also, if there are any vents or adjustment valves on the radiator get a closeup of those.

gerry gill

sounds like

you may have some bad radiator traps, to me. When is the last time you rebuilt them?

EdS

Excessive water demand

Gerry, I suspect you may be right. I just finished a couple of Dan's books last week hoping to get an answer to my question. I am now much more knowledgeable. I did not realize the life span of radiator traps. Mine must be near 20 years without service. I also appear to have what looks like a large trap near the end of the returns. I will try to add photos in response to the above post. Thanks for everybody's input.

EdS

Excessive water demand

No underground pipes. Here are photos.

nicholas bonham-carter

thirsty boiler

by the look of those small diameter pipes, i would say you have a vapor system, which runs best on just a few ounces of steam. if your pressure is spiking, that may prevent the traps from working temporarily, or permanently. put a 0-3 psi gauge (gaugestore.com) and get your pressure as low as possible, which may be easier if using a vaporstat.--nbc

Steamhead

That's a Dunham Return System

one of the more-popular Vapor systems. You will find it in chapter 15 of "The Lost Art of Steam Heating".



The small "trap" at the end of the dry (overhead) returns is known as a "Float Trap Air Eliminator". It is actually the main air vent for the system. It contains a float which keeps water from escaping if it backs up into the returns, and a vacuum check valve in the top which allowed the old coal boiler to pull a vacuum and keep generating steam as the coal burned down. This feature doesn't work well on oil or gas though.



At the end of each steam main, you will probably find a radiator trap piped between the steam main and the dry return. This "crossover trap" acts as a vent for the steam main, letting the air jump over to the dry return where it can leave thru the FTAE. If this trap is stuck shut, the air can't escape the way it should. If it sticks open, steam will get into the dry return and pressurize it, slowing or stopping the flow of steam to the radiators. Either way, that main will heat slowly.



The large "trap" is called a "Return Trap" but it is really a pressure-powered pump which can force condensate back into the boiler if the boiler pressure gets too high. Nowadays we have Vaporstats to keep the boiler from over-pressurizing, but a Return Trap can serve as a pair of suspenders to the Vaporstat's belt.



Vapor was the Cadillac of heating in its day, and is still one of the best systems out there. Find a good Steam Man and you'll be sitting pretty.



Where are you located?

EdS

Excessive water demand

Thanks so much. I will re-read the chapter.

I live in Denver.

crash2009

Great pictures Ed

Here are a couple more for your file.