Closing Steam Radiators on Second Floor

Giovanni722

Hello,

I have steam radiators throughout my house but I also have heat pumps as secondary heating. My second floor heats perfectly fine with the electric heat pumps but my first floor doesn’t. I want to close the radiators on the second floor and heat my first floor with my steam boiler. Would I see any cost savings here if I close the radiators and heat upstairs with my electric heat pumps? Is it safe to close the radiators on the 2nd floor? Would any damage be done to my heating system/pipes in the wall?

any help would be greatly appreciated!

EBEBRATT-Ed

No harm in trying if the old radiator valves hold. If they leak by you might get some banging.

In addition, steam boilers are sized based on the # and size of the radiators connected to them. By shutting off some radiators you are effectively making the boiler too large.

I doubt you will save much if any money but trying it should not damage anything.

Steamhead

@Giovanni722 , you don't say where you're located, but if it gets down near or past freezing your heat pumps will be frightfully expensive to run, and comfort will suffer. Use the steam.

bburd

If the supply valves on the second floor radiators do not hold, you can stop them from heating by installing quality adjustable air vents (like Vent-Rite #1; some of the cheaper ones will not shut off completely) and turning them to the minimum; or by turning the existing air vents upside down, or removing them and plugging the holes. Brass plugs will be easier to remove later.

Giovanni722

I appreciate all the answers! I live in the northeast (New York to be exact) @Steamhead Ultimately what do you guys think I should do?

Also, do you guys leave your heat on while you’re not home? I shut mine off and then turn it on 2 hours before we get home.

Jamie Hall

I assume this is one pipe steam? That is, each radiator has a steam inlet and a vent?

If so, unless the inlet valves are steam tight, which is highly unlikely, a small amount of steam will get in there and condense — and not be able to escape. Best care is it will just make some noise. Gurgling perhaps. Worst case is if any of those rooms should freeze, that water will destroy the radiator.

Don't do it.

If you need to reduce the heat upstairs, as noted turn the vents upside down.

If this is two pipe steam, it is safe enough to close the inlet valves, always assuming that there is no chance of freezing.

Now. Two things will happen once you do. First, the boiler will now be much more oversize than it likely already is, and will short cycle like crazy. This will reduce the efficiency some. The other is you now be dependent on those heat pumps for the heat — and in colder weather they will be every bit as expensive to run as the boiler.

So. What many people do is use the boiler to do the heavy lifting, and use the heat pumps to bring the temperature in specific rooms up to whatever the occupants of those rooms want.

As to turning the heat off — well… in warmer weather I suppose that that is an option. In colder weather, how long does it take to get the house back up to a livable temperature? At some point it makes more sense to leave the heat on. As an experiment, compare how often and how long the boiler has to run to keep the house up to temperature while you are away with how long it has to run to warm it back up when you get home As a side note, although in modern living it's often not a problem, such deep temperature cycling is very bad for quality furniture and musical instruments, not to mention plaster.

Giovanni722

yes it is a one pipe system, And that’s what I usually do on the really cold days, I heat the house up with the steam system and then try to keep the temp with the splits. Everything you said makes sense @Jamie Hall , I appreciate the insight! I’m just trying to find the most efficient way to heat this house because I went from an old house to an even older house somehow… in my previous home I had only forced air system, and here I have 2 choices, so just trying to see what’s best and cost effective.

LRCCBJ

If so, unless the inlet valves are steam tight, which is highly unlikely, a small amount of steam will get in there and condense — and not be able to escape. Best care is it will just make some noise. Gurgling perhaps. Worst case is if any of those rooms should freeze, that water will destroy the radiator.

A small amount of water is always at the bottom of steam radiators and will definitely freeze if given sufficiently low air temperature. This will cause NO ISSUE as the small amount will just lay frozen in the bottom without any capability of expanding sufficiently to crack the radiator. Note that a HW system has no such benefits at low temperatures as the radiator is FULL of water.

Do we believe that the valve………….not steam tight………….will be watertight and prevent the condensate from returning after the boiler shuts down? If so, the radiator will eventually fill with condensate. I seriously doubt this will occur.

pecmsg

Closing the supply's ASSUME the valves hold and there's no condensate inside that radiator.

There are covers that can be used, the steam still is used but little if any heat is given off. No chance of freezing up. The steam is still available when that heat pump eventually goes down and parts are on order.

ethicalpaul

https://forum.heatinghelp.com/discussion/comment/1821691#Comment_1821691

It can happen. The steam is under pressure and can enter a slightly leaky valve. Then the water is up there under actually lower pressure because there's not enough room for the water to escape and also allow air to enter (with the valve closed).

When the valve is open, pressure does not come into play, counter to some popular belief around here—people mistakenly think that vacuum in the system can prevent water from exiting the radiator. Not the case as long as the valve is open. But I digress.

Jamie Hall

I guess until you've seen it happen, you can't believe it ever will… I agree that the small amount of water remaining in the bottom of a steam radiator usually won't cause a problem with freezing. Usually. I have seen it push the sections of a radiator apart, however. This is usually fixable, but a bit of a bore.

I have also, incidentally, seen the trap in a two pipe radiator which is almost turned off or turned off in a cold space freeze. This is also a bit tiresome…

I actually doubt that our OP will have either of those problems, except in a prolonged power outage in cold weather. What his problem is going to be is short cycling of the boiler due to the reduced load.

LRCCBJ

https://forum.heatinghelp.com/discussion/comment/1821698#Comment_1821698

Once the system shuts down, the air vent opens and provides all the air necessary to allow the water to leak past the valve…………over a bit of time…………