Radiator bottom colder than top

iizbor3d

Helping out a friend, his room is colder than the rest of the house. I noticed his main vent is not sufficient so I upgraded it to a Gorton #2. After installing, I did thermal images of the radiators in his bedroom on the 2nd floor and noticed the top of the radiator is 130 degrees and the bottom only 100 degrees. The other radiators on the 2nd floor are 190 degrees. I noticed the vent on his radiator is a Gorton # D. Is it possible the vent is venting too fast and causing the temperature difference between the top and bottom? Also the room where the main vent is located has an open window. It was really cold, could it be causing the steam to condense before it reaches the two radiators in his room? 

Big Ed_4

I would check the radiator shutoff and vent ...

iizbor3d

The shutoff is fully open is there something else to check on it? The vent is 3 years old, will confirm if it opens and closes as it should. 

Jamie Hall

It would be normal for the top to be warmer than the bottom -- but it should be a lot warmer than that. Somehow it isn't getting the steam it needs or wants. As well as the valve (are you really sure it's fully open? Sometimes they get cranky...) but it also could be a restriction in the pipe leading to the radiator.

How hot is the feed pipe?

Big Ed_4

Remove the vent and see if the radiator gets hot. The valve handle seems low from here , why I mentioned it..

iizbor3d

Here's another picture of the valve just in case it actually does seem low. I'll try removing the vent, but I do hear hissing from the vent.

iizbor3d

Jamie Hall said:

It would be normal for the top to be warmer than the bottom -- but it should be a lot warmer than that. Somehow it isn't getting the steam it needs or wants. As well as the valve (are you really sure it's fully open? Sometimes they get cranky...) but it also could be a restriction in the pipe leading to the radiator.

How hot is the feed pipe?

I'll double check the temperature of the feed pipe. Good idea

TonKa

iizbor3d said:

Also the room where the main vent is located has an open window.

Why?

iizbor3d

TonKa said:

iizbor3d said:

Also the room where the main vent is located has an open window.

Why?

"The tenant feels an open window will keep the dust away" I said it makes no sense, but it's not my business to get involved. I did ask to experiment by closing the window for a couple days to see if there's any changes. 

mattmia2

where is the vent on the radiator? is it on the left and encrusted in filth?

iizbor3d

Yes, middle left. 

mattmia2

I think the orifice that sets the vent rate unscrews from the top of those, you might want to unscrew it and make sure it is clear.

iizbor3d

I haven't seen Gorton vents with removable orifices. I could be mistaken, will double check. 

mattmia2

Either way make sure it hasn't sucked up all that crud around it.

reggi

Is this something new or has it been like this for a while ? Is the insulation on the wall laying against the Radiator ? What is above the Radiator and below it , it looks like there's contact with mess underneath it...If air can't move , and the heat is getting absorbed by the insulation before it could get the cast iron hot I'd say there's a good chance your problem is simple...
Housekeeping and make sure the radiator isn't loosing what heat it's getting to the Insulation..
Just my thoughts by what I can see..
Other than whatelse that has already been mentioned by others that is

iizbor3d

Some further observations made. The valve is fully open, and vents are working fine; however, they don't stop hissing. Once I removed the radiator cover, I discovered the radiator itself is actually heating evenly and is 190 degrees all around. However, with the radiator cover installed, the top is hot to the touch and 130 degrees the bottom is cold and about 100 degrees. Could this cover be the issue and not allowing proper heat distribution form the radiator? I removed the insulation under the radiator just in case, but no changes in temperature. I also noticed the main only has a vent on the furthest end from the boiler. Since the vents don't stop hissing, I'm assuming one Gorton #2 isn't enough to vent this main? Also I discovered a portion of the return is cold. Is it possible there's a clog? 

ethicalpaul

If you're measuring the temperature of that grate, that's not a surprising result. I think if you took the grate off you'd see the whole radiator (top to bottom) is more or less the same temp.

ethicalpaul

This also isn't surprising. That is one weird piping arrangement you have (with possibly the highest, shortest "header" ever), but this section of pipe that you are measuring here isn't going to get any steam (nor likely anything else) so I'd expect it not to get hot

iizbor3d

ethicalpaul said:

If you're measuring the temperature of that grate, that's not a surprising result. I think if you took the grate off you'd see the whole radiator (top to bottom) is more or less the same temp.

Yup there's a significant difference when remove the grate. Maybe the grate should be changed to something else to allow more heat into the room? 

ethicalpaul

Yes, that is a very restrictive grate for sure. You might want something that has larger openings on the bottom and the top to make a chimney effect where the cool air is drawn in at the bottom and gets warmed, rises, and exits the top

TonKa

Covers block A LOT of heat - something like 40% or more. Additionally, because your cover is unpainted, somewhat shiny, and with a gap between it and the radiator, it is reflecting a good deal of radiant heat in the wrong direction. Just painting the backside of the cover and cutting a slot of one inch or so at the top and at the floor to allow for better air convection and would increase output... assuming the room needs it.

reggi

@iizbor3d So the issue was that you were taking Heat measurements through the grating and when you checked it W/O grating the temperature was normal ( Hot ) ... ?  Just seeing what was missed.. Glad you found it !