steam radiators not heating

steam radiators not heating

PostBy: abobb On: Mon Sep 23, 2013 9:20 pm

OK, this one is for the steam gurus. I have inherited a problem, a house with 16 steam radiators and a leaking coal-fired steam boiler in the basement. I will be changing the boiler directly, but I've been told some of the radiators were not heating. There are two pipes to each radiator and a trap on each return in the basement and a steam vent on each radiator. There is also a condensate pump behind the boiler that hasn't worked in years. Is it necessary for the pump to work and is that why some radiators do not heat?
abobb
 

Re: steam radiators not heating

PostBy: blrman07 On: Mon Sep 23, 2013 10:01 pm

Steam cannot get in if water (condensate) cannot get out. The pump has to run to pump the condensed steam back into the boiler. Get the water out of the lines and the condensate tank and you will get steam flow.
blrman07
 
Hand Fed Coal Boiler: Bucket a Day
Hand Fed Coal Stove: Vigilant Casting 2310
Baseburners & Antiques: rebuilding a 1906 March Brownback Double Heater, using a UMCO 1920's Pot Belly stove in the church
Coal Size/Type: Pea/Nut/Wood in the VC and anything that will fit in the Bucket a Day. It's not fussy.

Re: steam radiators not heating

PostBy: agcowvet On: Mon Sep 23, 2013 11:26 pm

Or if the traps are failed shut--or if they are failed open (more common, as I understand it), and you have live steam in the returns it will likely inhibit heating also...the traps, are they on every radiator's line? Condensate pump may or may not actually be necessary, it may have been a later addition to the system as a 'quick fix' or it may be needed. Be SURE to get piping, etc squared away; if there are any leaking buried returns the constant addition of makeup water will really shorten the life of the replacement boiler. Not to mention the poor and/or inefficient function if other piping and venting are wrong.

Be sure to check out heatinghelp.com, Dan Holohan's books for sale there, and the forum "The Wall" they have a section strictly on steam http://www.heatinghelp.com/forum-catego ... ctly-Steam and also have a "Find a Pro" way to find someone who isn't a knucklehead.

I am not a heating contractor but this subject is naturally interesting to me.
agcowvet
 
Hot Air Coal Stoker Furnace: efm AF150
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Newmac NL-2 (oil)

Visit Lehigh Anthracite

Re: steam radiators not heating

PostBy: Pacowy On: Tue Sep 24, 2013 12:30 am

I don't think anyone has mentioned it, so I'll add the possibility that the vents are not functioning properly.

abobb, what is the boiler that has failed, and with what are you planning to replace it?

Mike
Pacowy
 
Stoker Coal Boiler: H.B. Smith 350 Mills boiler/EFM 85R stoker
Coal Size/Type: Buckwheat/anthracite

Re: steam radiators not heating

PostBy: abobb On: Tue Sep 24, 2013 9:29 pm

The leaking boiler is an EFM 520 and so will be the new one as we are using the same ash base and stoker unit and only changing the boiler and controls. There doesn't appear to be any leaks in the return system as all pipes are exposed, none buried.
abobb
 

Re: steam radiators not heating

PostBy: dryrot42 On: Wed Sep 25, 2013 1:27 pm

Hi, I don't currently run a steam boiler but I worked on oil fired steam for years. There are two basic types, one pipe and two pipe. One pipes need the radiator pitched towards the intake for condensate to run back out of the radiator. They also need a vent to allow air out and steam in. Two pipes should be level or slightly pitched towards the return pipe. Some twos have a thermal valve in a tee where the return comes out of the radiator, which if not functioning will prevent steam coming in. Some twos use vacumn to return the condensate, some use gravity, if the traps are plugged or water can sit in the line, no steam to the radiator. Small amounts of water in the pipes from improper pitch cause a banging noise as steam builds. Check these out and see if it helps.
dryrot42
 
Hand Fed Coal Stove: Godin Large Oval, Godin Large Round
Baseburners & Antiques: Have used a Mistletoe, Kineo, potbelly, Franklin coal
Coal Size/Type: Blaschak pea, nut, and stove depending on the weather
Other Heating: Oil furnace
Stove/Furnace Make: Godin
Stove/Furnace Model: Large Oval

Re: steam radiators not heating

PostBy: DePippo79 On: Fri Oct 04, 2013 10:49 am

I'm no expert, but I would like to mention another option. Seeing how you already have a two pipe system and replacing the boiler anyway you might want to think about going to forced hot water. Might be able to create zones also. Have to check to see if rads can be used for water. Should have continuous path top and bottom of the sections. Plus DHW can be a indirect tank zoned off the boiler. I have read that steam heat is better though, more heat energy. Definitely recommend the books by Dan Holohan. Please keep the radiators. Matt
DePippo79
 
Baseburners & Antiques: Glenwood Oak 40, Stanley Argand No. 30, Glenwood Modern Oak 114, Stanley Argand No. 20 missing parts.
Coal Size/Type: Anthracite. Stove and nut size.
Other Heating: Oil hot water.

Re: steam radiators not heating

PostBy: Pacowy On: Fri Oct 04, 2013 11:44 am

If you switched to hot water with the same radiators I think you'd lose around 38% of the heat transfer capability you get with steam.

If your system needs to have a vacuum for the condensate to return that pump should probably be checked. It also couldn't hurt to check/clean the vents and traps for the radiators that don't work.

Mike
Pacowy
 
Stoker Coal Boiler: H.B. Smith 350 Mills boiler/EFM 85R stoker
Coal Size/Type: Buckwheat/anthracite

Re: steam radiators not heating

PostBy: dryrot42 On: Fri Oct 04, 2013 11:55 am

If the radiators have vents on top they can be used for hot water provided they dont leak anywhere, also they should be re-piped, as the size of the steam pipeing would be wasteful of heat. Useing the existing pipeing as a gravity hot water system would also require fixing the blockages which are causing the current malfunction. There is nothing like warm radiators for cold subzero days. My experience with old steam valves is that if all they need is stem gland repacking he would be fortunate, which reminds me, sometimes a valve head on the globe valves commonly used, can fall off and block steam from coming into the radiator, something I failed to mention earlier. Useing two pipe wrenches one can usually unscrew the valve top and see if the valve is still together inside, obviously done when the boiler is off and no steam on. It helps to loosen the packing gland and sometimes to work the valve when unscrewing the top. Be sure to run some pipe sealant on the threads before replacing the valve top. Re-pipeing the entire system complete with new shut offs at each radiator and zoned circulator pumps or zone valves would be the Caddilac but would cost equivilently.
dryrot42
 
Hand Fed Coal Stove: Godin Large Oval, Godin Large Round
Baseburners & Antiques: Have used a Mistletoe, Kineo, potbelly, Franklin coal
Coal Size/Type: Blaschak pea, nut, and stove depending on the weather
Other Heating: Oil furnace
Stove/Furnace Make: Godin
Stove/Furnace Model: Large Oval

Re: steam radiators not heating

PostBy: dryrot42 On: Fri Oct 04, 2013 11:57 am

Make that manual vents, not the chrome automatic vents steam radiators have. :D
dryrot42
 
Hand Fed Coal Stove: Godin Large Oval, Godin Large Round
Baseburners & Antiques: Have used a Mistletoe, Kineo, potbelly, Franklin coal
Coal Size/Type: Blaschak pea, nut, and stove depending on the weather
Other Heating: Oil furnace
Stove/Furnace Make: Godin
Stove/Furnace Model: Large Oval

Re: steam radiators not heating

PostBy: DePippo79 On: Fri Oct 04, 2013 3:33 pm

Forgot about the pipe sizing. I'm still learning. Abobb and Dryrot42 noticed your both new members welcome. Dryrot42 seems like you really know your stuff. Thank you for helping me understand a little more about steam. Matt
DePippo79
 
Baseburners & Antiques: Glenwood Oak 40, Stanley Argand No. 30, Glenwood Modern Oak 114, Stanley Argand No. 20 missing parts.
Coal Size/Type: Anthracite. Stove and nut size.
Other Heating: Oil hot water.

Re: steam radiators not heating

PostBy: Rob R. On: Fri Oct 04, 2013 4:48 pm

Check the function of the radiator vents, any traps, and also check the pitch of the radiators and pipes. It is common for houses to settle over time and disturb the pitch of the piping. What is NOT common is to find a heating guy that knows anything about residential steam. Educate yourself and seek out a good steam man to help you with the repairs.

The condensate pump may or may not be required...it could have been added in an attempt to fix another problem.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: steam radiators not heating

PostBy: dryrot42 On: Fri Oct 04, 2013 6:57 pm

Thanks Matt, when I was younger I had a master oil license and serviced some buildings with 30 plus apartments heated with steam, some quite sophisticated. A common problem was having a radiator shut off because it got too hot. When a steam valve is turned off but not tightly, the face or seat would wire draw or cut like a hack saw had been used. It would then leak by and trap water. All the preceding suggestions have merit but they are from far away. You will have to troubleshoot a little on your own, bearing in mind what has been said. In the basement look for a loop which starts from the top of the boiler. a second loop ends at the base or in the pump. The first should have risers going to the individual radiators and the second have drops returning from the individual radiators. With steam up go around and carefully feel each riser to find the trouble spots. If the radiators have vents, open them up if you can, or unscrew and listen for the rush of air then put them back. If the radiator has heated up by taking the vents out, the vent is the problem, if no vent follow the outlet pipe back to the cellar. Where the heat stops should be the trouble spot. I've seen pipes clogged full of rust. If the radiators have no vents, then plan on replaceing the bellows in the outlet or return valve. By going through all the steps you should be able find the trouble. Most small systems don't need condensate pumps but if yours has one and it's defective none of the radiators except the first one or two in the loop should heat. If the return elbow at the radiator looks like a globe valve without a handle it should have a thermostatically controlled valve inside, if it's just a 90 degree elbow your problems are in the return loop. If you locate a problem in a section of pipe, you can replace it buy breaking an elbow, done by backing the fitting with a sledge from one side, then striking the fitting with another sledge from the other side. You can repipe with a new fitting and two pieces of pipe with a union in between. Good luck and let us know, Richard.
dryrot42
 
Hand Fed Coal Stove: Godin Large Oval, Godin Large Round
Baseburners & Antiques: Have used a Mistletoe, Kineo, potbelly, Franklin coal
Coal Size/Type: Blaschak pea, nut, and stove depending on the weather
Other Heating: Oil furnace
Stove/Furnace Make: Godin
Stove/Furnace Model: Large Oval

Re: steam radiators not heating

PostBy: international86 On: Sat Nov 02, 2013 9:15 am

Hi abobb, I just happened to see your post and am a bit late in this reply, but thought I'd go ahead anyway. You mentioned that there are two pipes on each radiator. Does one (the return) have a trap? If it does, there should not be a steam vent on the radiator. It is common for traps to fail, and once one does, it will generally cause the rest to fail. Once this happens, most times the "fix" would be to put air vents on the radiators. The system may work, but not efficienty. There is also a trap at the end of the steam line near the boiler which should be checked also. This vents the air from the steam lines. Also, your condensate pump must be operating. It's what pushes the condensate back to the boiler. Without it, your return lines will be flooded and most likely your system will be very noisy. If you don't think you can fix all of this by yourself, I'd call in an expert. Your system sounds like a vapor steam system, and if it is, it's the Cadillac of steam heating systems. Don't even think of converting it to hot water, as that would be an expensive option. The pipes are sized and pitched for steam. Converting to water would mean a lot of changes. One thing to consider is that a vapor steam system operates at less than 1 psi. Hot water uses a lot higher pressure, unless it's an open system, and most are not. This would mean that with the higher pressure, you'd most likely have leaks that were not apparent with the lower operating pressure of a vapor steam system. I noted that one of the posts gave a link to heatinghelp.com, which is an EXCELLENT resource for anyone who wants to learn how steam works. Once operating properly, you will love your steam heating system!
international86
 
Hot Air Coal Stoker Furnace: Keystoker A-80

Re: steam radiators not heating

PostBy: Chrispo624 On: Tue Nov 12, 2013 7:34 pm

I ran into this problem today. The Burnham steam boiler was not sending heat evenly to all radiators, after looking at all options I found that the chiminey was blowing off a lot of steam. Problem solved, boiler was cracked and steam was going outside instead of inside the home
Chrispo624
 

Visit Lehigh Anthracite