1st floor radiator won't heat

Pin

Hi all,

I am doing a gut renovation on a 3 story townhouse and we changed to new pipes on all the risers, valves, and a section of the main line. For some reason, a radiator on the 1st floor on the rear left side of the building heats up way too slow. 2nd and 3rd floor radiators connected to the same branch that comes off of the main line is heated all the way across. All 3 radiators have the biggest air vents (Gorton D and Maid-o-Mist #D) on them. The main line is vented very quickly with 3 vents up on an antler. What could be the problem?

Some details: the boiler is located at the front of the building and there is one main line that goes towards the back of the house. At the back about 2-3 feet from the end, there are two tees that branch to the right and left side of the house. Each side of house has 3 radiators (1 per floor). The right side heats up without a problem. The left side is slower but its farther and hence I have 3 big air vents on those radiators. The branch to the left side of house has a horizontal section that's 11 feet long that's runs alongside a floor joist and tees off for first floor radiator (see picture). That pipe continues and then angles straight up to 2nd and 3rd floor radiators. Every pipe is pitched correctly so no problem there.

Shouldn't the 1st floor radiator get heated before 2nd and 3rd floor if there are on the same line?

Thank you,
Pin

SWEI

Is this a one-pipe or a two-pipe system? If two-pipe, is that a supply or a return tap?

Pin

One-pipe system.

SWEI

How do you expect the condensate to climb up and around that loop?

Steamhead

How big are the radiators?

When the pipes were changed, did they make any of them smaller?

Pin

SWEI said:

How do you expect the condensate to climb up and around that loop?

What do you mean? The pipes are all pitched to have the condensate flow back into the same pipe the steam came from. One-pipe is a counterflow system.

SWEI

The photo shows what appears to be a trap (water seal) of some sort. Is it upside down?

Pin

Steamhead said:

How big are the radiators?

When the pipes were changed, did they make any of them smaller?

The 1st floor radiator is small. 4 tubes and 8 sections.

Pin

SWEI said:

The photo shows what appears to be a trap (water seal) of some sort. Is it upside down?

No idea why my plumber use that many elbows. Those loops do get hot but it just doesn't flow fast.

I had them disassemble that section and no water at all in those pipes so I don't think its trapping water there. I also asked them to remove that radiator on 1st floor and just have an open valve to see how fast the steam comes out. The steam comes out puffing and after 10min or so of complete open valve, then it starts shooting straight steam.

SWEI

I thought at first the photo was looking down a riser. It appears to be looking up at the subfloor.

Pin

SWEI said:

I thought at first the photo was looking down a riser. It appears to be looking up at the subfloor.

Yeah sorry. Let me clarify. The picture is from the basement looking up at the subfloor of the 1st floor. The loop is for the 1st floor radiator and the pipe continues on into the far corner and angled up to the riser to provide steam for 2nd and 3rd floor.

Fred

@SWEI It's hard to put that pipe in perspective. The pipe that the Tee is on is the horizontal pipe running along the floor joist. It should drain Ok. I suspect the large radiator vents the OP has on the other radiators makes those radiators hog the steam until they are filled and then this radiator get steam, hence the 10 minute delay. Try putting smaller vents on those radiators and see if that helps. Steam is going to take the path of least resistance. You will have to play with the radiator venting to get all the radiators balanced. To test this theory, I'm also guessing that if you turn the thermostat up 2 or 3 degress so that the boiler runs longer, that problem radiator will get hot too, as soon as the others fill. Remember, vent mains fast, radiators slowly.

Pin

Fred, I just tested your theory and it seems like the 1st floor is now getting more heat faster.

To add onto the theory, I also suspect that I have too big of vents on the right side of house (which has shorter pipe run from the main) and its pulling steam away from left side.

Steam travelling down the main gets to the right side tee first before left side tee (although the two tees are about less than a foot apart), so my guess is lowering the vents on right side should help with the situation.

Pin

1st floor rad is still slower relative to the 2nd and 3rd floor radiators after I adjusted the vent sizes.

Now I'm thinking maybe I should put a vent by the radiator valve inlet to help vent the runout. That runout is about 11 feet horizontally from the main line so maybe the 1st floor vent (Gorton D) is too small to handle all the runout plus the radiator.

Will this solve my problem? Will there be issues if I do that?

BobC

Throttling the input of a single pipe radiator is usually a bad idea. What kind of vents are on all the radiators and what do you have for main vents in the cellar?

Bob

Fred

Make sure both ends of those mains have suffecient main vents on them first, then continue to adjust the radiator vent sizes until you get them all balanced reasonably well. It sounds like you have two mains, connected with a Tee. Ideally each of those mains should come directly off of the boiler header . Putting main vents on each end of those mains will help steam move more easily into each.

Pin

I have one Gorton #2 and two Gorton #1 on an antler for the main. I have Gorton D on the 1st floor rad, Maid-o-Mist C on both the 2nd and 3rd rads.

There are two mains that come from the boiler, one for the front of house and one for back of house. The one in question is the one that goes straight to the back of house.

The line that goes to the back of house has two tees at the end that serves the right side and left side. The tee for the right side of the building is first of the two and the runout goes horizontal for about 3-4 feet before going up towards the 1st, 2nd, and 3rd floors. The tee for the left side of the building is the last tee on the line and the runout goes horizontal for about 11-12 feet before going up towards the 1st, 2nd, and 3rd floor.

Right now, both sides reach the 1st floor connection at about the same time (right side might be faster slightly). The right side will continue to heat the 1st floor and then move on to the 2nd and 3rd. However, for the left side, the steam will stop just right at the radiator valve for 1st floor and the steam continues on the riser towards the 2nd and 3rd floor to heat those first.

What troubles me is why the steam won't heat the 1st floor rad first before moving on to the 2nd and 3rd even though there are on the same pipe coming off of the main line? The steam just seems to be stucked right at the rad valve.

Fred

The most likely reason is that the steam is met with more resistance at the first floor radiator than it is meeting in the riser getting to the second and third floor radiators. I know you put slower vents on the second and third floor radiators but apparently not small enough yet. OR, that first floor vent is stuck closed and not letting any air escape from that radiator.

BobC

Buy yourself a handful of Maid O Mist 5L's, they come with 5 interchangeable orifice sizes. Start with the smallest ones upstairs and see how things go.

Bob

Bio

Your system is unbalance, over venting on some and under venting on others, I would put all MOM #5 on ALL radiators for even distribution

KC_Jones

I agree those D vents are the same size as a main vent and unless you have some really weird crazy situation you shouldn't ever need them and certainly not on a first floor radiator. I would do as suggested and downsize all the vents, start small then increase as required. Also BobC's recommendation of getting the adjustable package is a good one. You can start small on all then increase as needed. It's much easier to start small to get balance. One you put a D vent on you can't go bigger and adding vents is going the wrong way. That rad isn't getting steam because all the other rads are also over vented.

Abracadabra

Vent the raidiators slower. #D is way to big and will cause you issues. The 2rd and 3rd floor are stealing steam from the 1st floor.

#4s all the way around. Adjust to a #5 if necessary.

Jamie Hall

Are you sure that the valve for that first floor radiator that won't heat is open? Are you really sure? It wouldn't be the first time that a valve had failed closed...

Pin

Jamie Hall said:

Are you sure that the valve for that first floor radiator that won't heat is open? Are you really sure? It wouldn't be the first time that a valve had failed closed...

Yes, I made sure it was open. I took off the valve to make sure it was working fine.

I did what you guys suggested and lowered the vents on almost all the radiators. There seems to be some improvement but the problem still persists. The 1st floor will only heat 1 section of the radiator and just seems to stop while the 2nd fl and 3rd fl will continue to heat all the way across.

I have mostly #4 and #5 on the radiators with a few #C on 3rd floor radiators due to its large sizes and distance. Each floor seems to be balanced with front slightly more than rear (boiler is in the front of house). In the rear of building, the right side is still faster than left side although I have #4 already on the right side. I think the fact that the runout from the main is a 11 feet horizontal section is the reason for the delay, which is okay but the steam just seems to want to go up to 2nd and 3rd fl instead of 1st. (I have #6 on the 2nd and 3rd fl which is in balance with the right side of house)

The 11 feet horizontal section seems to be like an extension of the main line so I'm thinking maybe it best to add a vent to vent that line quicker. The only place I could vent now is on the 1st fl rad inlet valve. Not sure if that will help at all.

Could it also be because of the loop that you see in the picture?

Bio

You mention you have 3 vents on the main, are they gorton 2?

New England SteamWorks

Worth a shot: Did you verify that the troublesome radiator is properly pitched towards the valve? (Put some checkers or blocking under the far pair of legs). Steam always moves from high to low pressure and takes the path of least resistance. Pitch, that loop, under-sized or wrong type of valve, under-sized piping are all things to check.

Pin

Bio said:

You mention you have 3 vents on the main, are they gorton 2?

I have one Gorton #2 and two Gorton #1 on an antler for the main. Main is about 45 feet long and 2" pipe.

Pin

RI_SteamWorks said:

Worth a shot: Did you verify that the troublesome radiator is properly pitched towards the valve? (Put some checkers or blocking under the far pair of legs). Steam always moves from high to low pressure and takes the path of least resistance. Pitch, that loop, under-sized or wrong type of valve, under-sized piping are all things to check.

Yes, pitch is towards the valve. Valve is a standard brand new valve and been tested that it works.

I have taken the valve off from the pipe and leave it as an open pipe to see the speed of steam coming out. Steam first puffs as it comes out and only after like 10min it'll start shooting straight steam. Not sure whether that loop is causing the problem.

New England SteamWorks

What is the EDR of the radiator? Does the 11' horizontal run-out serve only this radiator? (If not we would need the EDR for all radiators on that run-out to check the pipe sizing). That loop could be trapping a little condensate. The radiator starts to heat up, condenses, -then no more steam. Hard to tell from the pic, but that tee in the loop is coming off at a 45º right? After the tee, is the loop pitched? That loop isn't by the book, -the tee should face the other way, but there doesn't appear to be enough room to do that?

New England SteamWorks

Additionally, your valve should be sized to the EDR of the radiator, not the pipe. Once we get the EDR we can see if 1" pipe is adequate in that loop, but assuming it is (max EDR 45), if your radiator is more than 20 EDR you need an 1-1/4" valve. And you do know that steam valves are different, correct?

Pin

The EDR of the radiator is about 20. That 11' horizontal section serves 3 radiators, one on each floor. That loop you see is for the first floor Rad and it's pitched downwards so shouldn't trap any water. I took that loop apart before and there were no accumulation of water.

KC_Jones

Have you tried slowing down the upstairs rads? Put #4 vents on both of the other ones and maybe a #5 on the first floor? I think there is more at play here. I have seen a phenomenon on low or no pressure water systems were a tee like that will not allow much flow on the take off. Most of the water will shoot straight through the tee and take the easy route, steam would typically act in a similar fashion due to the low pressure and the additional elbows aren't helping that situation. I would suggest the above of slowing down those upstairs rads as much as possible and see what happens.

Pin

After adjusting the other rad vents down, the situation seems to be improving. I've noticed that there's an imbalance between front and rear of building. The front is getting hotter faster which makes sense as the boiler room is in the front. I already have the front rads on #4 so can't go any lower. The front rads are on a separate main that is short so is it necessary to even have a vent on that main line? I believe that if i were to remove that main vent and just have the rads do the job of venting that line, I can slow down the front rads more and be in balance with the rear.

Fred

You need the vent on that main. Allowing the rad vents to do all the venting will just create even more balancing problems for you. I have a similar loop as your on one of my rads and it works just fine. I think the next thing to do is total the EDR for all of the rads fed by that one pipe. It is possible that pipe is not large enough to supply that total EDR. If that's the case, you may have to slow all the radiators on that run down even more. There are smaller radiator vents than #4's. You may not have any but this may be a case where adjustable vents, like the Hoffman 1A or varivents would be less expensive to use as they will let you adjust them down and not buy fixed ones.
Slowing the front rads down may be another option in that it may allow more steam to hit that back main. You can't just balance one main. You have to balance the entire system.

New England SteamWorks

What Fred said. In Dan's book, any horizontal run-out longer than 8' should be up-sized one. In your photo you've got 1-1/4" which maxs out at 55 EDR up to 8'. 1-1/4" at 11' would max out at 28 EDR...

What is the EDR of all 3 of the radiators?

Pin

All 3 radiators has a combined EDR of approx 65.

Now that I lowered the vents on other rads, those 3 radiators on the rear left side are heating up pretty well. I had the vents too big on the right side of house which prevented the left side from heating up. I also had too big vents on the 3rd floor. Now for the left side I have #C for 1st fl (due to the longer horizontal runout), #6 on both 2nd and 3rd fl. For the right side, I have #4 on 1st and 2nd fl and #5 on 3rd fl. These seems to balance nicely and they all heat all the way across now.

I didn't realize that I had the vents too big on some and lowering on some radiators actually speeds up the heating process. Good thing to know for the future.

Thank you guys!

New England SteamWorks

Something to keep in mind: Reducing the venting on other radiators in the system to get steam to the problem radiators can work, but at a cost. Ideally if all the piping is sized correctly the steam can zip around very quickly to every radiator and keep the run cycle to a minimum. It appears that your 11' run-out is under-sized and this will result in longer run cycles (and higher fuel costs) because everything else has to be slowed down to balance that under-sized 11' run-out.

Pin

Since the run out is undersized, do you think it's better to add a vent at the 1st fl Rad valve inlet in order to vent that run out quicker so left side of house can get heat quicker?

Fred

You've got three radiators already venting that run-out and riser. IMHO Putting another vent on isn't going to make a significant difference especially at the first floor where it will likely close very quickly anyway. Just remember to balance all radiators across the entire system, not just on one main and remember it is always desirable to vent mains as fast as possible and radiators slowly, anyway. You should be fine.