Please help: New old house with steam system, many questions (loud banging, cold radiator, etc)

geoffh

I have a house that was built in the mid 1920s. We recently purchased it and the first thing we did was convert from oil to natural gas. The heating system is a steam system that vents into our chimney and connects to 1-pipe radiators throughout the house.



The house is relatively small and 2 floors. The boiler is in the basement so the 2nd floor bedrooms are 2 floors above the heating source. We have a total of 8 radiators in the house (kitchen, 2 in living room, dining room, bathroom and one in each of 3 bedrooms).



As part of the installation the plumber put in a new boiler and also replaced all the valves and vents. The vents have a dial on the bottom that goes from 1 to 8.



Questions:

1) What do the numbers on the vents really mean? What should they be set to?



2) How often should I have to 'add water' to the system in the basement?



3) The house seems to heat quite nicely except for one room. It is an upstairs bedroom and is the farthest from the heat source. It is located on a wall where the other side of the wall is the bathroom radiator. When the heat is on normally, this radiator stays cold. I do hear steam coming out of the vent. If I crank the heat up a little more I can feel heat in the pipe leading to the radiator. If I crank it up a little more I hear a ton of clanking and banging and eventually the radiator gets quite hot. It's turned up to 8 (highest setting on vent) and the valve is definitely wide open. What should I do?





-I've heard that radiators should be tilted toward the input valve. This faulty one is level.



-I've heard that 'bleeding the radiator' can help with trapped air, but have no idea how to do this.



Thank you!

BobC

Pitch, clean, and pressure?

Your vents sound like Ventrites with a white dial at the bottom of the vent. 1 is off with 8 being maximum. Systems work best when the venting on the radiators is slow while the venting on the steam mains is fast. Don't just turn everything up to 8, that almost never works. In general you want the radiators on upper floors A LITTLE faster than those near the boiler.



What kind of main steam vents do you have?

About how long is the steam main and what size is the main (circumference is fine)? Post some pictures of your new boiler showing the piping around it and a picture of the main vent'(s?) would help. Also give us a picture of the problem radiator showing both ends.



Radiators should have a gentle slope towards the input pipe, you can lever it up with a 2X and shim it with quarters or a thin wood shim under the vent end. It sounds like you have water laying in a pipe somewhere, when steam encounters standing water it collapses and that is the bang you hear. See if the pipe in the basement that feeds this problem radiator has some slope in it that allows water to drain back towards the boiler. Watch out for any dips in the piping that might be pooling water.



You shouldn't have to add water any more often than once a month and hopefully less often. Has the boiler ever been skimmed to remove the oils from the installation?



Does the water in the sight glass move around a lot when making steam?



How high is the pressure just before the boiler shuts down from making steam?



Bob

geoffh

Answers

Hi Bob, thank you for all the helpful answers. I'll post more detailed responses when I get home and can have a proper look. From memory, here is what I know:



1) The vents look like this:

http://www.heatinghelp.com/images/posts/5461/thumb_vent-rite-1.jpg



Right now I have most of the upstairs vents turned between 6 and 8 and the bottom floor vents between 3 and 4. Does this seem reasonable?

What do you mean the main vent? Where would I find that setting?



When you say to lever it up with a 2x, what does this mean? Do I need to disconnect the radiator from the supply line prior to shimming it up?



Regarding the water, I've never added other than a few weeks after the initial install. I was asking because a neighbor of mine says he adds water "every time he goes into the basement" and it made me nervous. I have no idea about the skimming after install.



When the system is off, water in the site glass is at the appropriate level. When the system is on, sometimes I can't see any water at all (or very minimal). Is this normal?



One additional question: The air vents hiss quite loudly when the system turns on. Is this normal?



I'll get the other info and pictures when I get home

BobC

radiators

are heavy and considering yours and the pipes connecting them are well along in age it's best to treat them gently. If you can fit a stout piece of wood under the belly of the radiator and use a block of some sort you can GENTLY lever the end of the radiator up off the floor so you can insert a shim under it. Don't try to disconnect the radiator, just go slow and don't force anything.



The radiator vents you are using are very good vents but they do not have the capacity to handle all the air in your boiler header and steam main. Discussing the settings of the radiator vents does not make sense till we know what the main vents are. A large capacity main vent will assure that main fills with steam quickly so each radiator vent only has to handle the air in it self and the pipe that connects it to the main. main vents usually sit close to the end of the steam main or at the return where it makes a dive for the boiler return, they can be silver, copper, green, or rust colored (if it's old). It's important that you have one large enough for the system to work efficiently. If your radiator vents are hissing loudly it probably means you need more venting on the main and the boiler pressure may be too high.



If your neighbor is adding water often it means he has a leak and if he doesn't find it and fix it he will be the next one to buy a new boiler. Fresh water contains oxygen and oxygen eats cast iron over time so the less water added the better off you are. If you do have to add water to a boiler it's important to do it slowly and to have the boiler make steam right after adding the water so the boiling will drive off the oxygen in the fresh water.



The water inn the sight glass should not move more than about 1/2", it sounds like your boiler needs skimming. Boilers and piping come coated with oil and all of that oil has to be removed by skimming the oil off the top of the water surface, this takes hours and you usually have to do it several times to get all of the oil out. Did the installer install a skim port, if not what make and model boiler is it?



Bob