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pdugan1185
steam radiator thermostat

I have a old house with a steam boiler system. Some parts of the house are comfortable when the heat is on but some rooms get very very hot. Can I install thermostat valves on individual radiators to help "zone" the heat? If so, where can I purchase them?

JacktheShack
Re: steam radiator thermostat

Do you have a one-pipe steam system or a 2-pipe steam system.

They do have for sale what's called "thermostatic radiator valves", usually for one-pipe systems, but they are tricky to install and may not work on your system.

Do you want to attempt to install this yourself or have a contractor install it???

There are also other ways to stop the overheating radiator in a particular room, such as installing a metal plug in place of the Hoffman vent.

Google "thermostatic radiator valve" steam for numerous sites on this issue.

http://www.heatinghelp.com/newsletter.cfm?id=101
http://www.homeenergy.org/archive/hem.dis.anl.gov/eehem/93/931111.html
http://www.deadprogrammer.com/deadprogrammer-visits-the-radiator-planet

pdugan1185
Re: steam radiator thermostat

How can I tell if I have a one pipe or two pipe system?
I will do the work myself..if I can't mess it up too bad.

JacktheShack
Re: steam radiator thermostat

One pipe systems have a single pipe coming out of the floor attached to the radiator; there is also a little vent valve on the opposite side of the radiator.

Two-pipe systems have a supply pipe coming out of the floor & going into one side of the radiator, and a return pipe going out the other side into the floor.

Please post back to advise which system you have.

pdugan1185
Re: steam radiator thermostat

It's a two pipe system with no vents or bleeders.

JacktheShack
Re: steam radiator thermostat

Two-pipe systems usually have a thermostatic steam trap on the RETURN side piping of the radiator, just before it goes down into the floor.

(The SUPPLY side piping is of wider diameter, has the shutoff valve & supplies steam to the radiator; the RETURN SIDE piping is smaller, usually of 1/2" diameter).

Overheating in two-pipe systems is almost always caused by the failure of the little brass thermostat (bellows) and seat inside the trap, which is inexpensive; a replacement can be obtained at any plumbing supply shop in your area.

Access to the little thermostat (bellows) and seat is obtained by removing the top nut of the trap with a plumber's wrench to remove the bellows & seat.

Temporarily shut off the heating system; then remove the top nut of the trap with the wrench, and remove the inner parts; you can temporarily replace the top nut & turn on the heating system while you take the failed part to the plumbing supply shop for the replacement.

If the nut won't budge, apply some penetrating oil to loosen the nut threads, and try again several hours later.

There should be some printing on the steam trap that identifies it, along with the name of the manufacturer.

If you have this type of steam trap, they commonly fail after 3-5 years, so the bellows in the traps of the other radiators in the house that are also overheating would have to be replaced also; but do one at a time to make sure this is the cause.

Please post back if your system doesn't seem to have the described thermostatic steam traps.

http:www.heat-timer.com/newsletters/newsletter2.pdf

pdugan1185
Re: steam radiator thermostat

The only radiators with steam traps are on the third floor. The overheating radiators are on the second floor. Do you think the traps on the third floor are the cause?

JacktheShack
Re: steam radiator thermostat
pdugan1185 wrote:

The only radiators with steam traps are on the third floor. The overheating radiators are on the second floor. Do you think the traps on the third floor are the cause?

Anything's possible; I think it's probably best to get an experienced steam heat service person in there to see how the 2nd floor piping is set up, and then recommend the needed changes based on that.

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