Five questions about steam

CoachBoilermaker

1. Is there really much oil savings in trying to slow a vent to make an empty room's radiator fill more slowly? Or is this a comfort thing? Is the same amount of oil being burned if one of the radiators inlet valve is closed and/or it is given a slow vent?
   
2. What is the effect of a radiator vent that is stuck open? Steam escaping the radiator. Won't the escaped steam also heat the room? Lower water level in boiler?
   
3. Should I put teflon tape on a new vent? The old ones I removed did not have teflon, and did not appear to leak.
   
4. One radiator's vent is not reachable without lifting away the metal cage/case. When a radiator is encased by an old metal enclosure, are you guys able to lift it off the radiator with only one person?
   
5. If a steam radiator vent is stuck closed, can any sections of the radiator on the inlet side still get hot? ie: With a stuck closed vent, can a radiator still get partially hot? Or none of it would be able to get hot at all?

Jamie Hall

Shutting off — or slowing — a radiator is mostly a comfort or balance thing, but if it keeps an outside room cooler it will save energy. The amount of oil burned is controlled almost entirely by the difference between the outside temperature and the inside temperature, for a given house.

A radiator vent stuck open has two major bad results. One is that the humidity in the room soars as the steam gets in. This leads to condensation and, if bad enough, failing plaster or sheetrock, mildew and mould on everything, and generally a nuisance. The other is it loses water from the boiler, which has to be replaced, and the more fresh water added to a boiler the faster it will rust out and fail.

You could use tape. You could use pipe dope. Some folks do one, some the other…

The metal cage question … depends on the cage. Some are easy to remove entirely. Some have panels which open for access.

A vent stuck closed will result in a little of the radiator getting sort of warm. How little and how warm will depend on how long the boiler runs.

KarlW

1. Probably not, but it depends on your controls. It can be done with a properly sized and vented system with a pressuretrol/vapourstat set to the correct pressure can shut your burner off and not add pressure without adding heat (what happens when you overpressurize your system) - this is absolutely true of gas, where there is little efficiency lost in re-ignition, possibly not with oil. These controls can be challenging to get setup. I did it, but it took replacing all my steam traps and adding larger air vents to avoid water hammer.
2. Not really; the heat isn't the steam itself, but the giant hunk of metal you are heating up and letting radiate. This will lower the water level in your boiler and add potentially unwanted humidity to a room.
3. Yes, use teflon tape on gas fittings, they are good to 400 degrees and superior to things like lampwick which was used at the tome.
4. Need more detail/pictures to answer this. Radiator cages vary even more than radiators.
5. No, only the inlet pipe will get hot, and it doesn't provide enough radiation to heat a room. I found this out the hard way when a TRV failed shut in my bedroom a couple of years back.