Jm66208
Member
...and its leaking. Question is should it even be there? There is a real lack of knowledgeable boiler people in these parts, so you never know what you will run into.
Hoffman valve on 2 pipe steam?
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rjbphd
In the Trades
Vague explanation, if you meant valve on radiator, you can trottle the steam coming into the radiator. . Unlike the one pipe system. What part is leaky?
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Jm66208
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Sorry, should have said hoffman VENT. The silver bullet looking thing on the side of the radiator. This is the only radiator that has one, and its hissing continuously. Radiator is hot.
Most radiator VENTS are adjustable, most will eventually stick and need to be replaced. Two pipe steam does not (or should not) have both a steam trap AND a vent, such as this:
It's likely that the trap failed closed, and somebody added the vent to get it to heat without the expense of replacing the trap, which isn't exactly legit. If the vent is sticking open you can replace that band-aid that sorta-worked, but to get it to work as-designed probably means repairing or replacing the trap, and plugging the tap for the vent.
A radiator steam TRAP for 2-part steam should NOT be leaking steam:
It's likely that the trap failed closed, and somebody added the vent to get it to heat without the expense of replacing the trap, which isn't exactly legit. If the vent is sticking open you can replace that band-aid that sorta-worked, but to get it to work as-designed probably means repairing or replacing the trap, and plugging the tap for the vent.
A radiator steam TRAP for 2-part steam should NOT be leaking steam:
Jm66208
Member
Thanks dana! Ill remove the hoffman vent, plug the hole, and see what happens. If the radiator doesnt get hot, I'll replace the trap.
Jm66208
Member
Any chance the trap is stuck closed? Im just wondering how much water will spill out when i remove the old trap.
The trap most probably is stuck closed, but probably still seep-drains or you would have water spitting out of the vent and the radiator wouldn't heat well.
The maximum potential volume is dictated by the size of the radiator and how high the vent is located on the radiator, but a shallow pan under the connection to the radiator (or the top cap, if that's easier) would allow you to start & stop the flow of any fluids with the wrench. My best guess is that it's mostly dry, but with a long-since dysfunctional steam trap that isn't guaranteed. Be sure radiator is below scalding temps and have something ready to mop up with when you crack it open. It's not under significant pressure- if it contains much water it'll dribble rather than spray.
Plugging the illegitimate vent will probably cause a somewhat higher system pressure and may affect burner cycling or how well it heats the other radiators during the experiment, just to be aware.
Most 2-pipe steam systems can be converted into pumped-water hydronic systems without ripping the house apart, which may be worth doing in the long term, assuming you plan to live there for awhile. Whether it would be able to keep up with the design-day temperatures at the lower output of hot water vs. steam could be determined with a bit of analysis of the total radiation size. An upper bound for how much heat you really need to get out of the radiators can be determined from fuel use per heating degree-day data. With the heat load numbers and the radiator size numbers the maximum water temp needed can be estimated. Steam systems are often 3-5x oversized for the actual heating loads, and have enough radiator to deliver the heat at much lower temperatures than 215F steam. It's a much bigger project than just swapping out the stuck traps & vents, and may or may not be "worth it", but lower, steadier radiator temps are definitely more comfortable. If your radiators have been painted a bright white, glittery silvery or glittery golden color (as almost all surviving steam system radiators are) that was usually done to REDUCE the rate of heat coming off the radiator, primarily for comfort reasons!
The maximum potential volume is dictated by the size of the radiator and how high the vent is located on the radiator, but a shallow pan under the connection to the radiator (or the top cap, if that's easier) would allow you to start & stop the flow of any fluids with the wrench. My best guess is that it's mostly dry, but with a long-since dysfunctional steam trap that isn't guaranteed. Be sure radiator is below scalding temps and have something ready to mop up with when you crack it open. It's not under significant pressure- if it contains much water it'll dribble rather than spray.
Plugging the illegitimate vent will probably cause a somewhat higher system pressure and may affect burner cycling or how well it heats the other radiators during the experiment, just to be aware.
Most 2-pipe steam systems can be converted into pumped-water hydronic systems without ripping the house apart, which may be worth doing in the long term, assuming you plan to live there for awhile. Whether it would be able to keep up with the design-day temperatures at the lower output of hot water vs. steam could be determined with a bit of analysis of the total radiation size. An upper bound for how much heat you really need to get out of the radiators can be determined from fuel use per heating degree-day data. With the heat load numbers and the radiator size numbers the maximum water temp needed can be estimated. Steam systems are often 3-5x oversized for the actual heating loads, and have enough radiator to deliver the heat at much lower temperatures than 215F steam. It's a much bigger project than just swapping out the stuck traps & vents, and may or may not be "worth it", but lower, steadier radiator temps are definitely more comfortable. If your radiators have been painted a bright white, glittery silvery or glittery golden color (as almost all surviving steam system radiators are) that was usually done to REDUCE the rate of heat coming off the radiator, primarily for comfort reasons!
rjbphd
In the Trades
Another thing to check is the main vents on the return near boiler... whatever you do, hire only experienced hydronic heating guy. . Not just some plumber because it's pipings or forced air heating company because it s heating.. I'm currently working on two different systems that been butchered by forced air company.
Jm66208
Member
Well I removed both Hoffman vents and plugged the holes. Everything seems to be working fine. System pressure still about 2-3psi. There are two vents on the main lines in the basement. One on the supply line, and one on the return. When the boiler kicks off, the one on the supply line hisses & gurgles for a min or two and spews a 1/4 cup or so of water. Still not sure why those Hoffman vents were there.
rjbphd
In the Trades
Get the LAOSH book. ...
Jm66208
Member
Thanks, I'll look the book up. Unfortunately, i cant seem to find anyone knowlegeable the area. As far as botched up systems, please see my other thread on the two pipe steam system that was converted to pumped hot water. Its a real mess...
rjbphd
In the Trades
I have done many successful from steam to hot water conversions, only on the systems that had been butchered beyond repairable by forced air companies. Otherwise, I keep the steam systems working with improved controls.
Jm66208
Member
What do you mean by "improved controls"?
rjbphd
In the Trades
Using vaporstat instead of pressuretrol, installing tekmar steam boiler control( for large system ),etc
Jm66208
Member
Ok, I've been called in to look at this "bath remodel gone wrong". Original contractor put the supply lines to this radiator in the wrong spot so a "reputable" boiler guy cuts hole in floor and moves pipes and plumbs radiator. Is it acceptable to have the supply line going down hill the way he has it, and is it ok to put the valve on the bottom? All other radiators in the house have the valve on top.
Jm66208
Member
Cant get pic to load from myphone.
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Jm66208
Member
rjbphd
In the Trades
No NOO, gawd NOOOOOOO... hope you didn't pay that handyhack!
Jm66208
Member
I didnt think it was ok. I asked them if it is making noises and they said yes. Hammer...
Condensate has to be collecting down by the valve. Should the valve be mounted at the top of the radiator?
Condensate has to be collecting down by the valve. Should the valve be mounted at the top of the radiator?
Jm66208
Member
Can you elaborate on why this is wrong, so I can be informed when I contact the installer?
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