Steam Radiator Spewing Water

klal

I have an issue with a single radiator (copper fin convector in a steel enclosure) on a one-pipe steam system which I ran (yes, not a professional) several years ago to a finished sun room (former porch). I ran this radiator off an existing riser from the supply main, in a wye configuration (yes, I know that it needed a dedicated riser, but at the time, due to budgets, it was either try an improper setup or no heat in that room at all). The riser runs from my toasty basement under the fully enclosed, but not heated crawlspace of the sun room, about 7 feet, and comes up through the floor on the far side of that room (the exterior wall side). The enclosed space under the room is cinderblock, and the riser runs through a 2 x 12 bay insulated with fiberglass batt insulation, and enclosed in with 3/4 plywood and caulked. So essentially, the bottom of the room is closed and insulated, not open to the elements, but is unheated. It always took the heat longer to get to this room, and when it did (with consecutive heat cycles), it spewed water from the valve. We replaced our boiler a couple of years back, and replaced all of the valves with Gortons that were specified by Gorton technicians to achieve proper heat based on distance from the boiler. That improved the situation a bit, as more heat was sent to the sun room, and although the radiator still spewed, it did improve somewhat. A few days ago, I had my plumber cut the supply main and install a proper dedicated riser to the sun room, eliminating the wye and returning the shared line to the original line it was split from, so now there are two dedicated risers, as they should have been from the start. Unfortunately, I am still getting water coming out of the valves, and although it seems to have improved again, spewing is still spewing, and I'd like it to stop. The radiator is extremely pitched (no mistakes about that) back to the radiator valve, and the valve shoots straight down into the floor to a 45 elbow and then a pitched run of about 7 feet to the newly added riser to the main. I originally thought that the condensation from the shared line was pushing water into the radiator, so instead of it running back to the supply main, it remained or even was drawn into the radiator. Now that they're separate, I'm not sure if the water is generated by the (colder) pipe inside the sun room floor. Any thoughts or things that I can try to troubleshoot would be greatly appreciated.

Jamie Hall

Fin tube is always difficult on one pipe systems. That said,, pitch -- and size -- are critical. You don't mention the size of the pipe under the sun room. Be sure that it is at least one size larger than would normally be used for the EDR of the radiator -- and that it is pitched at least 1" from end to end -- and I'd rather see 2". Is the pipe totally enclosed in the fiberglass insulation under there? If not, it should be insulated -- at least 1" insulation.

Fred

A couple thoughts come to mind, for me:
1. What size is the supply pipe? Is it 1" or less? it may not be large enough to allow steam and condensate to flow, in opposite directions at the same time.
2. Is the sunroom a step down? If so, how high is that convector above the boiler water line?

Big Ed_4

Pipe the fin tube two pipe and move the vent on the return line before it drops back down to the wet return or steam trap . Or change the fin tube to a radiator .. You can and should also insulate the supply pipes...

Steamhead

How long is the element in that convector? You may need to add a return line and pitch the element down to the return connection, to drain the condensate.

What type of radiation does the rest of the system have?

klal

Gentlemen, thank you for your quick and comprehensive replies. I will try my best to answer the questions you have to the best of my abilities and knowledge.

All but one radiator in the house are the original copper fin tube convectors that were installed with the (sadly retired) American Radiator Co. Ideal Red Flash boiler (I think it was a 1929 model, if I remember correctly). The only replacement is now cast iron, as the original had pinholed/cracked and couldn’t be repaired. The cast iron replacement is the unit that this spewing one was previously wyed to.

The supply pipe is not individually sleeved inside the bay under the sun room, rather it is between the layers of fiberglass batting, I think I made a sandwich with two pieces. I’ve even considered removing the plywood and having spray insulation applied to the underside of the sunroom.

The size of the pipe is 1”, as are the other 4 that run to the first floor (one level above the boiler in the basement), all the second level risers are (I think) 1.5”.

The convector in the sun room is 30” long, 5” wide, 5” deep, and is inside of a steel enclosure, about 5.5’ feet above the water line of the boiler. It is pitched 1” from end to end, but can be raised more if needed, the valve is a Gorton #6. See attached photo.



As I mentioned in my original post, the radiator goes into the floor, to a 45 elbow, to a straight run of pipe. I didn’t mention that it then steps down through a 1” street elbow which goes directly into a 1” 90 elbow, to a straight run of 1” pipe approximately 24” to a union, nipple, 45, nipple and back to the supply, see attached photo, second pipe from the foreground. Could the street elbow be causing the logjam of the condensate and steam since it narrows?



Again, thanks for all of your help, I hope I've given you enough details.

retiredguy

I do not want to break your bubble but I would call a steam guy to check the whole system. The 1" supply piping to that spewing convector is way too small to be used on a 1 pipe system. You may want to follow the advice of @Big Ed 4 or @Steam Head and add a return line or change the convector. I recently stayed at a B&B that had a 1 pipe steam system where a local contractor replaced all the standing cast iron rads with baseboard C. I. Burnham Base Ray or equivelent radiation. Now the system hammers and heats poorly.

Fred

That pipe in the foreground seems to be pitched the wrong way. Are you getting any hammer or gurgling from that run?
A 1" pipe should be able to handle about 25EDR. What is the EDR rating on that convector?
The Gorton #6 may be a little too aggressive with the 1" pipe. You might try a #4 or #5. It may slow the steam down enough to let the condensate flow back to the main.

klal

The original piping, back to when the house was built is 1" to the radiators on the first floor, no other radiators exhibit any problems, no water hammer, nothing—just this one convector. I'm guessing that it was built to proper specs, the old men of steam knew what they were doing back then.

As for the pitch of that foreground pipe, that's an optical illusion from the photo. It is pitched back to the supply main, and it heats with no issues. Although the foreground pipe is further away from the riser in question, it heats quicker/first, but I am guessing that is due to the fact that the riser with the issue is colder since it travels through an unheated space.

I don't know the EDR on that convector, it is two rows of fins that are 30" long, 5" high and 2.5" deep each. The steel enclosure is 32" wide by 20" tall.

I can try and swap out the Gorton #6 for a #4 and see how that affects it. Do you think I need to remove the street elbow that ties into the 90 elbow (far right of the picture) and replace it with a 90 elbow, small nipple, 90 elbow? The street elbow does narrow the diameter of the riser somewhat, not sure how much that impacts it, I'm guessing every little bit counts.

Fred

@klal said: "The original piping, back to when the house was built is 1" to the radiators on the first floor, no other radiators exhibit any problems, no water hammer, nothing—just this one convector. I'm guessing that it was built to proper specs, the old men of steam knew what they were doing back then."

Don't bank on what the Dead men of Steam did back then. Circumstances were different. Boilers ran on coal and ran constantly from the beginning of the season through to Spring. Steam was much slower moving through those pipes and at lesser volumes so condensate could flow back much easier. Today, with gas and/or oil fuel, boilers run in bursts and with a lot of steam being generated and flowing at much higher volumes, leaving less room for condensate to return during the heating cycle.
Try a slower vent first. I doubt that street elbow is much of a problem. Insulation and the 1" pipe may be.

STEAM DOCTOR

Don't know.if anyone mentioned this but mayne supply valve is not fully open

Jamie Hall

"I don't know the EDR on that convector, it is two rows of fins that are 30" long, 5" high and 2.5" deep each. The steel enclosure is 32" wide by 20" tall."

You have almost all the data you need to calculate the EDR. What you are lacking is the number of fins. If your fins are 5 inches by 2.5 inches, then you have 1 EDR for every 6 fins -- at least closely enough for government work. Just count them up...

klal

True, I was told my Red Flash was originally coal, converted to oil, and finally to gas, and it did run nonstop. When I had the boiler replaced, I thought there was something wrong when the steam was achieved and the boiler cycled off, and then on again when necessary.

Switching over to a #4 vent will be my next test to see the impact, insulation will be next.

The radiator supply valve is fully open, just double-checked.

As for the EDR, the convector is two sections, with fins on either side of the two halves. Not sure if we're just looking at the total number of consecutive number of fins when facing the front of the enclosure (43 ÷ 6 = 7.2), or each physical fin, front, inside front, inside back, back (43 x 4 = 172 ÷ 6 = 28.6).

I'm getting quite the education, and as an educator, I appreciate everyone's knowledge and patience, really do.

Big Ed_4

I noticed there is no insulation on any of the supply pipes . Without it adds so much more condensate (liquid water) with in the system . Your system was original designed with pipe insulation for a reason .

klal

Yes I would like to insulate the pipes, the basement is way too hot and that should help with that too. What is the best insulation for the steam pipes and risers? Originally I had asbestos, which was abated. And there was a section that the former homeowner covered in foil wrapped foam, which is useless. I've been told paper wrapped fiberglass, and someone said there is a cardboard wrapping, not sure if they meant the fiberglass. Recommendations?

Big Ed_4

The old asbestos insulation was corrugated.

.

EBEBRATT-Ed

@Kial

I am really surprised no one mentioned getting rid of the 2 90 degree elbows. (unless i missed it) I see no need for them and they are surely causing part of your problem. If you must have elbows there they should be 45s not 90s. Looks like that could be a straight run to me

Converting to two pipe is a better fix if you can get to a return line. 1" pipe can't take much of a back flow of condensate

Jamie Hall

On the EDR. What you want to determine is the actual total surface area of the fins (it really isn't mysterious -- though we often seem to make it so!). So it seems to me that your 28 figure is probably not far off.

Which is a lot for a 1 inch pipe -- particularly since copper fin tube condenses steam a lot faster at first than cast iron with the same surface area wouold.

JUGHNE

Is the inlet valve on the problem convector the same on the rest of the system? If it is a globe valve then possibly water could not drain back.

klal

At the least, I will convert those two 90 degree elbows to 45s. I'm not sure I can get a single run, but I will try.

Hopefully the insulation, changing the elbows helps the 1 inch pipe situation.

As for the inlet valve, it is the same original valve used on every other radiator in the home. Not sure if it is considered a globe valve.

Jamie Hall

It is at least a variation on a globe valve -- but set vertical like that, it won't trap water unless the washer (if it has one -- most do) has come off the stem.

JUGHNE

For piping, you could use a longer nipple riser on the main and maybe then a straight shot...the more slope the better.

STEAM DOCTOR

> @Jamie Hall said:
> It is at least a variation on a globe valve -- but set vertical like that, it won't trap water unless the washer (if it has one -- most do) has come off the stem.

This should be checked out. Washer might be partially or completely off the stem.

klal

I will definitely check the valve. I'll remove the handle/stem and see if there's an old washer lodged in there. Right now that valve doesn't need to close, so even if I can't find a replacement weather immediately, I can live without it. I can also try a longer nipple on the main (didn't even think of that, I've been fixated on the other side the whole time—maybe that's why I'm not a very good amateur plumber), but I have to get some nipples and elbows first. Thanks gentlemen, you really are helpful.

klal

Revisiting this thread. Long story short, I opened up the crawlspace to check for pitch (it is pitching properly) and had my plumber eliminate the elbows to the main so it is a straight run (there are a few elbows between where the radiator pipe goes through the floor and connects to that improved run, I guess it would be a "swing joint"? Runs about a foot if I remember it correctly). The elimination of the elbows near the main improved the situation, but there was still some spewing. I also did some valve swapping which helped, but again not fully resolved.

Before I close up the crawlspace again, I was wondering if I could get some advice. Do I make the change to a 1.25 pipe from the 1 inch, and if so, would that improvement be defeated if the radiator valve is still 1 inch as is the t on the main? I know 2 inch was suggested, but I'm not sure I can get it to fit within the crawlspace while maintaining pitch due to the size change. I know the increase in pipe size is to accommodate the steam and the condensate streams, so that the steam pumping up doesn't carry water with it, but will there be a "bottleneck" if the radiator and main are the 1 inch, and still pushes the water?

Regardless of the pipe diameter, I will be getting the fiberglass pipe sleeves, as high of an insulation value as I can to cover the pipes. The rest of the bay will be fiberglass batt insulation, and finally sealed with plywood.

Steamhead

Increasing the pipe size would be my next suggestion. A horizontal pipe, even pitched properly, cannot handle as much EDR as a vertical pipe.

Failing that, I'd change from fin-tube to a cast-iron radiator.

BobC

Fin tube and steam don't get along well because they produce a lot of condensate and the steam has to fight it's way past the returning condensate. They should be vented very slow and if all else fails increasing the pipe by on size may be necessary.

Bob

klal

I'm revisiting this thread, hopefully I can put this to bed. Quick summary: spewing water from a copper fin tube convector with a long pipe run (about 10 ft) under a non-heated crawl space, 1 inch pipe. Originally this pipe was y-ed. Since then it has been given a dedicated connection back to the main, and the extra elbows you see in the photos (pipe in the background) have been eliminated, so it is a straight run.

Advice has been to increase the pipe size and increase insulation on pipe (right now it is wrapped in batt fiberglass, but I will be purchasing fiberglass sleeves to wrap the pipes in which will be housed in the insulated 2 x 12 bays.

I have room, to increase to 1-1/4, but larger than that would require some unwanted demo, and the angles might be tricky based on the available pitch and foundation wall. My question is, would the 1-1/4 improve the situation enough to make it worth it (no spewing)? If yes, could I get away with the radiator and the radiator shut off valve connected to a 1 inch to 1-1/4 reducer (connecting to the 1-1/4 pipe dropping beneath the floor), or should I swap the existing valve out with a 1-1/4 valve and reduce between the radiator and the valve? Obviously condensate being pushed back up the line is my issue, and I'm not sure if the valve size will also impact that (i.e. water collection inside the valve due to bottlenecking).

I trust your professional advice and honesty, so If I'm not really guaranteed to get any significant improvement with these potential changes, I may opt to leave it alone and live with the spewing.

Thanks,
Ken

BobC

I have a 1" feed going to a small bathroom radiator (Radiant style) and it has had no issues. That radiator has an EDR of 17.5 so the 1" pipe is enough. How much EDR does your fin tube have?

A 1" horizontal pipe with condensate in it is rated for a maximum of 28 sq ft of EDR (1-1/4" will handle 55EDR) . If you drip that 1" pipe at the radiator that number goes up to 68 sq ft, adding a drip to that radiator might be your answer if you have the room.

Bob

klal

I don't think a drip/return is going to be easy given the space I'm dealing with. As for the EDR, the convector is two sections, with fins on either side of the two halves. Not sure if we're just looking at the total number of consecutive number of fins when facing the front of the enclosure (43 ÷ 6 = 7.2), or each physical fin, front, inside front, inside back, back (43 x 4 = 172 ÷ 6 = 28.6). If you scroll to the middle of the post, you can see what I'm describing in a photo that clearly shows both sections of fins.

Jamie Hall

Not rocket science, just pesky. What you want is the total surface area of each fin, counting both sides. Then multiply by the number of fins. So if I'm reading you correctly, it would be 28.6

Steamhead

Go ahead and increase to 1-1/4". The extra distance between the main and that convector warrants a larger pipe. And get as much pitch on it as you can. Also, if the shutoff valve is not a gate-type valve, replace it with one that is. A globe or stop valve restricts the flow of water and steam, which would contribute to the problem.

dopey27177

On one pipe steam a !" radiator valve has a capacity of 20 EDR.

Just a thought.

The 1" valve is equivalent to 17 feet of pipe.
The pipe fittings equal about 7 feet of pipe.
The length of pipe is about 3 feet,

This is an equivalent run of 27 feet of pipe.

The proper pitch for counter flow is about 1" per 10 feet of pipe,
the chart does not show anything beyond a 10 foot run.

At this juncture I would install an 11/4" horizontal pipe from the steam main with an 11/4" X 1 elbow looking up to the radiator.

There is a more expensive way to make this work and that is to make this radiator a two pipe system.

The outlet from the radiator will need a 1" radiator valve with 1" pipe, piped to steam main.

The connection to the steam main needs to be done with the bull looking down which will make a water loop (trap water).

The water loop prevents steam from flowing up the return piping.

Jake

klal

Jake, are you suggesting on the one pipe run (I don't think I'll be able to do the two pipe system) that I leave the 1 inch valve in place from the radiator (into the floor) have the 1 inch side that penetrates the subfloor connect to the 1 x 1-1/4 elbow and then continuing back to the main with a 1-1/4 pipe? If that is the case, the main is currently using a tee that is 1 inch. Do I use another 1 x 1-1/4 fitting at the main side, or should I replace the tee with a 1-1/4 tee?

klal

So is the consensus to leave the 1 inch valve in place and replace only the run from the main to the valve with the 1-1/4 pipe? I'm worried that the smaller diameter of the main tee and the smaller diameter of the shut off valve will make it hard for the water to make it back while the steam is pushing. Is this making sense?

Jamie Hall

The valve won't be a problem that way. The connection to the main could be. You want to use a T which has the main size on the through steam main, and the riser size on the leg. If you have to increase on the riser, either do it on a vertical or sloping (45 degree or more from horizontal) to be sure that your reducer doesn't trap water.

klal

So if I replace the current 2 x 2 x 1 tee with a 2 x 2 x 1-1/4 it would be ideal. But the 1 inch shut off valve increasing vertically to the 1-1/4 riser won't be an issue?

mattmia2

You could also use an eccentric reducer fitting.

Jamie Hall

klal said:

So if I replace the current 2 x 2 x 1 tee with a 2 x 2 x 1-1/4 it would be ideal. But the 1 inch shut off valve increasing vertically to the 1-1/4 riser won't be an issue?

The valve won't be a problem -- the increaser can't trap water in that direction. And yes, replace the 2x2x1 T with 2x2x1 1/4 would be ideal -- but depending on where you have unions on the main, and how long the 2x2x1 T has been there, that may not be a good option. So long as the fitting you use to reduce from 1 1/4 to 1 is not on a horizontal run, it won't trap water. Put it as close to the existing T as you can, though.

klal

I have a union on the main about 7 inches on center to the left of the tee. The run on the right is the one I am looking to replace. See the photo below.

And excuse my ignorance, I've done a quick diagram of what it would look like, minus some fittings to get the angle from where it terminates in the floor to the longest run of the riser. Is that correct in my drawing?

klal

I forgot to mention that the tee to the right is new, it was replaced in March, as is that union to its left, so if you're thinking as to whether or not it would be easy to take off, it should come off easily. Right now that smaller nipple between the tee and the 45 elbow is approximately a 30 degree angle or so, between 1 and 2 o'clock when referencing. It's not a vertical drop, but it's not a horizontal run either. If you think that a reducer at that junction would work, I think that's what you suggested, I'd be a bit more confident in making that change, since it wouldn't need a new tee. But if it's not a good idea, let me know.