single cold radiator

BCK

Hello everybody,

I recently purchased a home built in 1937 which has a hodgepodge of heating sources with the main being a gas steam boiler and 10 1-pipe steam radiators. I just read ‘We Got Steam Heat’ and have been poking around online looking for answers to the main issue I’m currently facing which is 1 of the 10 radiators usually does not get steam during regular heating cycles. I have to pump the temp up a degree or 2 and let the boiler run 30+ minutes before this radiator starts getting hot. I replaced all 10 vents with vent-rite #1s and have this radiator all the way open to 8 yet the problem persists. All other radiators work well.

After reading the book, there are a few issues that I know I need to tend to:
1. Vents on the radiators are whistling which leads me to believe I need to change the main vents next. There is a Hoffman Specialty No. 75 on one end but I can’t quite make out what model the other one is. It says VENTRITE diagonally across it and Anderson Products Inc, Cambridge MA. Both look very old and I’m assuming need replacement. Is this a DIY? They look pretty crusty and I don’t want to risk breaking a pipe. Any recommendations on what vents to go with?
2. 2 Valves are hissing and spitting a bit of steam out. Need to repack the nuts
3. None of the radiators are shimmed. They don’t look to be leaning the wrong way but I’m assuming adding a bit of correct pitch can’t hurt

I’m not particularly hopeful that making these fixes will help my one cold and lonely radiator though. There is a newer looking valve on this one while the rest look original so I’m thinking this has been an ongoing issue that previous owners threw some new parts at to no avail. It sounds as if there is some sort of backup. When the boiler first kicks in I hear a little air escape the vent, then nothing for ~20min. After that I hear gurgling and surging for 8-10 mins, more air out of the vent and finally it begins heating up. Any ideas on whats going on with this one?

Please let me know if there is any other info needed.

Thanks!

ChicagoCooperator

If your radiator vents are whistling your pressure is too high.

dabrakeman

Sounds like you have learned a bit already from your reading and are on the right track regarding a few things you do need to do like replacing your main venting and making sure you have correct pitch on all your radiators including the problem one and getting your pressuretrol set to lower cutout and cut in pressures.

Specific to your problem though, not getting heat to one radiator particularly if you have it vented well and it has a good new inlet valve is usually due to condensate blocking the path of the steam into the radiator. This would be due to a sag or incorrect pitch of the takeoff to that radiator. Can you trace the path from the steam main to the takeoff to that radiator. Sometimes the entire radiator can just be lifted a bit to improve drainage of condensate.

BCK

according to the good book i think my pressures are good:


does this look like a good valve for a steam system? i saw another post where an incorrect valve was causing issues:


there are 44' of steam main pipe which i believe is 2.25" diameter (all of the pipe is wrapped in insulation and i didn't think it woudl be good to disturb it. i found a piece of spare insulation in the basement that measured 2.25) leading to this hoffman main vent:


and 12' feet leading to this mystery ventrite:


Also, not sure how much it relates to the question but I believe over the years at least 2 radiators have been nixed as there is only hydronic baseboard heat in the kitchen and this renovated bathroom is just cold.
aimed at kitchen:


chilly bathroom (would like to get a radiator back in here soon...)

BCK

the cold radiator is on the 2nd floor so unfortunately i can't get a look at the piping after it leaves the basement. i will say there is a ton of rushing noise in the vertical pipe going up the first floor wall to this bedroom and pretty regular water hammer as well. bedrooms to either side heat beautifully

Hap_Hazzard

The setting on your pressuretrol only reflects your system pressure if it's working. If the pigtail is clogged, the pressure may get a lot higher. What does your pressure gauge read mid cycle?

mattmia2

I'd try slowly raising both ends of the problem radiator to see if the runout has sagged someplace like in the floor. It looks like someone replaced the riser out of the floor, if it is too long it could have pushed the piping down and caused a lateral to be pitched incorrectly in the floor.

BCK

unfortunately i just have the useless built in guage which is sitting at 7psi while the the system is off so i don't think it can be relied on for anything.

BCK

mattmia2 said:

I'd try slowly raising both ends of the problem radiator to see if the runout has sagged someplace like in the floor. It looks like someone replaced the riser out of the floor, if it is too long it could have pushed the piping down and caused a lateral to be pitched incorrectly in the floor.

thanks i'll try that. sorry if it's obvious but am i raising the radiator, and letting it cycle while raised to see if it heats up normally?

mattmia2

you are raising it and putting something like 2 pieces of wood under the feet to permanently make it higer and raise the piping attached to it.

The valve is all the way open, right?

Hap_Hazzard

BCK said:

unfortunately i just have the useless built in guage which is sitting at 7psi while the the system is off so i don't think it can be relied on for anything.

You might want to get a low pressure gauge to see what the actual pressure is. Vents shouldn't whistle. Can you tell if the boiler is cycling on pressure—i.e. does it turn off and on again before the thermostat is satisfied?

BCK

Hap_Hazzard said:

BCK said:

unfortunately i just have the useless built in guage which is sitting at 7psi while the the system is off so i don't think it can be relied on for anything.

You might want to get a low pressure gauge to see what the actual pressure is. Vents shouldn't whistle. Can you tell if the boiler is cycling on pressure—i.e. does it turn off and on again before the thermostat is satisfied?

maybe whistle was the wrong word, but i can hear air hissing out a few of them at times which made me think that the next step would be main vents.

i havent had any issues with the boiler short cycling and outside of this one radiator not working properly i'd say it works very well especially with me able to control some of the venting with the ventrite #1s now

BobC

I think you have water laying in a pipe somewhere that is condensing any steam trying to pass over it. How far will the radiator feed pipe let you raise that radiator?

Make sure the basement pipe that feeds that radiator has pitch so water will find it's way back to the boiler. Then lift that radiator up by whatever you can and use wood blocks under all four feet to hold it there and use a level to make sure that raised radiator has pitch so water can drain back to that pipe. I use a lever and block to raise radiators, this lets you do it in a controlled manor and lessons the chance of a mishap. I use strips of 3/4 -1/2 and 1/4" plywood, when you know what you need you can stain them so they blend in.

If this does help you can then lower the whole radiator gradually to find how high the thing really needs to be raised, be sure to maintain some slope so water can find it's way out.

Bob

KarlW

BCK said:

maybe whistle was the wrong word, but i can hear air hissing out a few of them at times which made me think that the next step would be main vents.

As I read here, hissing is the indicator you aren't letting air out of the pipes fast enough. On my two pipe system I removed the hissing air vents altogether and my system started acting much better. Yesterday I replaced the two valves with larger ones than I had and it still operates well.

Air vents should be silent gently letting the air out, not forcing the air out.

BCK

finally got around to getting some 1/4" shims on all 4 corners with no change in performance. it was pretty difficult to get shim under the foot closest to the wall and valve so i may leave this problem to the pros.

any recommendation for a non-knucklehead in Rochester, NY? from my search it looks like Ambrose Mechanical is the way to go