Water Clogging New Gorton Vents

1963tom

I have just completed balancing my system with new main vents (4 Gorton No 1 on an antler) and all new Gorton vents.  Sizes of the Gorton vents were selected based on the amount of air to be vented using Gerry Gills method.  The house is a combination of steam radiators and steam baseboard.  The system is working well, with one remaining issue.  The Gorton vents on the steam baseboards will occasionally clog with water.

What could be causing this?  The baseboards are 10 feet long, with the steam entering from the center (5 feet each section).  The baseboards are located on the second floor of a cape cod.

Mark N

Vents

What size vents on the baseboard? Shouldn't be bigger than a Gorton #4. Is the baseboard pitched toward the hand valve? is the hand valve completely open? Is this cast iron or fin tube baseboard? Post some pictures.

1963tom

More Info

New vents are Gorton No 4.  There is no hand valve.  The runner comes directly off the main to the second floor and enters a tee.  A 5 foot section of Slant/Fin Multi/Pak 80 tube & fin baseboard is attached to the left and right of the tee.  The board is mounted level on the wall.

 

I do not have pictures available, so will try to attach a sketch. 

MTC

I'm def no pro at those baseboards

but I would expect that if you're having issues with water in the vents, you need to do 2 things.



1. Tilt the baseboards slightly towards the steam Tee. It doesn't have to be much, but definitely want condensate to flow away from the vent and back toward the condensate drain line



2. If you're still having problems, maybe add a couple fittings to raise those vents up a bit higher. Looks like you have angle vents now from your drawing, maybe get a street 90 put into the vent hole, a short nipple and coupling, and a straight vent on top of that, to raise it up a bit out of the water zone. Probably doesn't need to go up more than a couple inches to make a big difference.

Mark N

Baseboard

That is not exactly the proper way to pipe baseboard on steam. I don't know how many sqft of EDR 10 ft of baseboard is. What size is the pipe feeding baseboard? I would think it should be at least 11/4". Are the rest of the radiators in the house cast iron? You shouldn't mix cast iron and copper fin tube on the same zone. They heat and cool at different rates.

1963tom

Pipe and Baseboard Info

Pipe size feeding the baseboard is 1.25 inches, the same size as the baseboard.  It is not cooper and fin, it is steel 1.25 pipe made for steam heat.  EDR is 990 BTU/foot, therefore 10 feet of baseboard is 9900 BTU.  This provides excellent heat for the room as long as the valves are not clogged with water.

The baseboards were installed about 35 years ago to provide heat to the second floor of a cape cod.  The main living space is all cast iron radiators.   

Mark N

Old Vents

What were the old vents that you used on the baseboard? Did you ever have any problem with these clogging? Vents don't get much slower than Gorton #4's. Check the level, make sure they are pitched toward the tee. Good luck>

1963tom

Old Vent Info

The old vents were Gorton C in one room, Gorton D in the other.  The valves would clog with water occassionly.  I would take them off, clear out the water, reinstall and be good for anywhere from 1 day to one month depending on boiler activity/outside temperature. 

After reading HeatingHelp.com, I realized the entire system was not being vented correctly (undersized main vents, too fast radiator & baseboard venting).   I completed balancing my system with new main vents (4 Gorton No 1 on an antler) and all new properly sized Gorton vents.  The sizes of the Gorton vents were selected based on the amount of air to be vented using Gerry Gills method.

The heating system is greatly improved, with the only remaining issue that the new Gorton No 4 on the two second floor baseboards clogs ever 2 - 3 days.  I don't know how to tilt the baseboards since it is solid 1.25 steel pipe mounted to a tee (if I raise one end the other goes down).

Does anyone know if a 1/4 NPT vent be better at draining water than the 1/8 NPT?

MTC

There's usually enough play in the piping and fittings,

to get a tiny bit of fall on each baseboard. Really, they shouldn't be mounted that way, 2 of them on a tee, so if you want to really fix it right, you should repipe them onto their own risers with 90 degree shut off valves. Then you could pitch them pretty easily.



I'd do what I suggested as far as the vents, if you still have a problem after correcting pitch. Get the vents up higher, and use a straight vent instead of an angle vent. They drain better, and it will be a bit further away from the water.



But I'd bet you won't have any issues if you can get a 1/8" pitch on each baseboard.

Mark N

LAOSH

The last section of Chapter 7 in LAOSH goes over One pipe steam baseboard problems. With 1 1/4" baseboard the pitch should be 1/2" per 10ft for 5 ft of baseboard.

MTC

As I said before, I'm not a baseboard expert

by any means, so please correct me if I'm wrong.



The way I am thinking, you have 5 feet of radiator in each direction at 990BTUh/lf, for a total for each radiator of 4950. If we convert this to EDR by dividing by 240, we come up with each radiator having a load of 20.625 EDR.



Looking at the chart from LAOSH, 1 1/4" baseboard has capacity of 47.2 EDR at a pitch of 1/4" in 10 feet (which is 1/8" in 5 feet, as I suggested).



For load on the riser pipe, we'd have to base it on the full load of both baseboards, which I believe 1 1/4" riser is capable of handling. The horizontal runout to that riser should probably be at least 1 1/2" I think - but I'm not really a piping guy, I more just work on existing systems.



Or am I figuring this wrong? I'm happy to learn if I'm not thinking correctly

Mark N

Pitch

You are correct the pitch is 1/4" in 10ft and I agree the straight shank vent might be the way to go for better drainage.

1963tom

Change to Straight Shank Vent

I will change to straight vents.  This is a much easier first trial at a fix.

I see that Gorton makes straight vents in both 1/4" NPT shank and 1/8" NPT shank.  Is it worth changing to the 1/4" NPT diameter shank vent for better drainage?  Is this overkill?

Thanks for all the help today on this issue.

MTC

I don't think its worth it

to change from 1/8" if that's what you already have.



I do, however, think that you're choosing to address the symptom first, rather than the problem. You may find some benefit in this route, but you will not have fixed the problem, just masked it.



Try unmounting each side of the baseboard and lifting it 1/8" and remounting it, if they're currently level. You may need to anchor the Tee to get it to do this w/o pulling up on the Tee, you may not. It would be better if not, so you don't get expansion/contraction noises.



I bet you can get 1/8" on each w/o repiping. Technically you could get by with a tiny bit less than 1/8". This is a much easier and more profitable endeavor than changing out your vents, though you will likely find that doing that as well will be of benefit.



What is sure is that you don't want level baseboard heaters.

1963tom

Good Suggestion

I understand your point, and you are correct.  I'll will try to see it I can get some tilt.

Thanks again for your help.