Joined on September 16, 2002
Last Post on December 5, 2013
@ October 16, 2013 9:13 PM in backflow preventer leaks when filling radiatorsbeside replacing it? If a backflow preventer is leaking -- usually through the atmospheric vent -- it isn't likely to be worth taking apart and fixing, unless it is a very big one (say 3 inch and up).
I'd just replace it...
@ October 15, 2013 9:01 PM in does new boiler need combustion analysis?need to be fine tuned after installation. Yes, they will be close right out of the box -- close enough so they will start and run. But every installation is slightly different, and you have to adjust them for best reliable performance -- and the only way to do that is with a combustion analyser, properly used. No excuses.
@ October 14, 2013 8:50 PM in Pressure test of steam linesdoesn't matter. What does matter is that there is simply no way that I can see to test a steam system for leaks with air. There is this little problem of the vents -- which are hopefully wide open when air is present.
Further, if you try to test with steam, you have another minor problem: you can't hold pressure, as the steam will condense very quickly.
And there isn't much point in doubling the pressure (even if you don't over pressure the vents and make problems where there were none before).
What you can do, however, is check the water use of the boiler. It should use very little, even in a large system (as might be found in a church). The manufacturer will have maximum values -- but in most cases I would venture to say that anything over a gallon a week is excessive.
I'm with you -- fix the know problem(s) and then check the whole system over -- and keep track of the water usage.
@ October 10, 2013 8:40 PM in Need new thermostat for single-pipe steam systemseparate problems here. First off, the Honeywell Pro4000 which Joe suggests is indeed close to an ideal thermostat for steam. Easy to hook up, easy to program, reliable. All good stuff.
As Joe says, though, the problem of cold edges and warm centre on cold winter days may well be due to problems with venting. As you may have read around here, if the air can't get out of the system, the steam can't get in. Therefore, it is necessary for even heat that the mains be vented very fast, so that steam can get everywhere in the system at about the same time. Then it is also essential, in single pipe steam, that each radiator be properly vented. You don't want the radiators too fast, but you do want them so that they all heat more or less evenly. If you do have colder rooms, then you can speed up the venting on the radiators in those rooms (up to a point) to get more heat there. It's worth experimenting with.
Also -- at the risk of sounding like a broken record -- make sure that the pressure on your boiler is low enough. 1.5 psi is ample. Oddly, the higher the pressure the more uneven and slower the heat will be (it also costs money...).
Make sure your new thermostat is mounted in a representative room -- and one which you often use!
The problem of uneven heat on a windy day is common in older houses, and is caused by infiltration. Storm windows, if you don't have them, help a lot. Just tightening up the windows and doors can help.
@ October 9, 2013 8:20 PM in Drop header lengthon this one -- assuming the drop header is upsized -- at least, one, two is better -- the water droplets are never going to make the corner to get into the risers to the steam mains. Mine works beautifully, and it is less than 15 inches (haven't measured it) -- but it's a 4" header with 3" risers off the boiler and over to it.
@ October 9, 2013 1:10 PM in Mass of water and short-cyclingIf it's steam we're talking about, no -- would make very litte difference, as the cycling is on pressure and a soon as the burner shuts off, steam production stops and pressure starts to drop, regardless of the mass of water (the mass of hot iron, on the other hand, does make a difference, although a small one).
@ October 8, 2013 9:12 PM in steam traps and putting in a new boilerthat boiler size. Three and a half inch mains are pretty big.
If the near boiler piping is done correctly, in careful accordance with the manufacturer's instructions, then going from the header into the large diameter mains shouldn't be a problem. I would suggest, though, that you may get better results if you come vertically off the header at header size (double check those manufacturer's instructions for that size! And it would be better if the header were a size or two larger than the riser, even if the manufacturer doesn't call for it) and increase to the main size in the vertical leg, rather than increasing in the horizontal once you get up there.
As to the eastern Washington problem. Indeed, there are large parts of the country where people who really understand steam are pretty thin on the ground. However, if you will purchase the set of books (Lost Art of Steam Heating etc.) they will give you a good knowledge of steam heat (it really isn't all that complicated -- simpler than hot water, by a long shot) and if you have a good, honest workman plumber, who knows how to thread pipe and is willing to learn something new, you and he (0r she!) can work together to get a steam heating system which really works beautifully.
Oh yes -- and don't either you or your plumber be afraid to post questions on the Wall. The best in the business read it, and are more than willing to help out.
@ October 8, 2013 6:05 PM in Short cycling steam boilerFirst, rusty water will not cause short cycling. Your water doesn't look bad to me (it's certainly no worse than mine); live with it.
Second, bn is being kind. That near boiler piping isn't just bad, it's horrendous. Find the boiler manual and find where it states how the boiler is to be piped, and then do it that way. The boiler piping, as it is, suggests to me a third way in which the boiler may be short cycling.
To review: there are basically three controls for a modern boiler (there may be more, but these three are the main ones). The thermostat, the pressure switch, and the low water cutoff.
The thermostat responds to room temperature, and has either an anticipator or a timer in it as well. You mention a digital thermostat. Therefore, step one is to check the digital thermostat and make sure it is set either for steam or for one cycle per hour.
Second, the pressure switch. It does not cause short cycling directly, but it will cause short cycling if the venting is poor. Judging by the state of the near boiler piping, I would want to check the main venting; anyone who puts in near boiler piping like that may have not realised the importance of main venting.
Third, the low water cutout. It would not, normally, cause short cycling -- but as bn noted, I don't see an equalizer on that boiler. Therefore, when pressure builds as it should, water will back out of the boiler and into the returns -- and enough water may back out to trip the low water cutout. Nothing to be done about that (it's only doing its job, after all) except to fix the near boiler piping.
@ October 8, 2013 5:54 PM in Hartford Loop?what happens if the check valve on the feed pump fails and there is no Hartford loop...
but maybe I worry too much.
@ October 7, 2013 9:45 PM in steam traps and putting in a new boilermight be ideal, it isn't necessary. Nor is replacing the traps (unless they aren't working). Do make sure that all the pipes are pitched correctly, though.
Steam pressure is critical. It should never -- ever -- in a residential system be above a pound and a half, and it is very likely that it will work best at about 8 ounces cutout. For that you will need a vapourstat on the new boiler. Your man who recommended 2 to 4 pounds is either mistaken -- as NBC hoped -- or just plain wrong.
Boiler size is critical, as noted. So is near boiler piping. So is making sure that the new boiler is installed so that its working water line is within an inch either way of the water line on the old boiler; this may require raising the new boiler on a pedestal.
@ October 7, 2013 5:15 PM in Zoning with thermostatic valve electric actuatorswhich you are probably aware of. The boiler will short cycle on pressure, since it will effectively be way oversize. It will still use less fuel than running the whole show, but not as much less as you might think.
Depending on how the piping is arranged, you might want to use a valve on a steam main, rather than on individual radiators. If you were to do that, that valve must -- absolutely must -- be full port. Which could be pricey; you'll want to look into the most cost effective way to do that. Also if you were to do that, you will need a drip to a cold return on both the hot and cold side of that valve.
Do not valve off the returns, either wet or dry.
@ October 6, 2013 7:49 PM in King valvejust that it won't work awfully well, as you found out. You might actually do better leaving the king valve open, since you don't have a valve on the returns, thus equalising the pressures in the system.
But a valve for the returns would be a good idea anyway. It should go on the wet return before it attaches to the Hartford Loop. While you're at it, put a couple of handy drain valves there, too, one on each side of the valve. Useful things, drain valves.
@ October 6, 2013 5:18 PM in Short cycling steam boilerFirst off, I'd avoid chemicals if at all possible. They shouldn't be needed in a heating system (closed cycle) boiler, unless the water is really aggressive in some way.
You need to establish just what part of the control system is turning off the boiler -- cycling it.
Steam Whisperer's comment is very relevant -- particularly if you (or somebody!) have replaced a thermostat. Worth checking.
Otherwise, it is more likely to be cycling on pressure -- but you need to establish that. If it is cycling on pressure, the very first place to look is the pressuretrol. Is it set right? Is it behaving properly? I have seen situations where (usually on vapour systems, at very low pressure) the normal pressure fluctuations in the boiler were enough to trip off the pressuretrol. A snubber on the pigtail will solve that problem. Also check the 'trols settings. Then you need to check the venting. While it is less likely to create a problem unless you have changed something, it is possible that the main vents have gotten stuck shut.
You might also spend a little time and think through what might have been changed in the building between when it ran OK and when it started short cycling...
@ October 6, 2013 5:09 PM in King valvebut, did you also close the valve or valves on the return, so as to isolate the boiler from the system? If you just closed the steam king valve, but left the returns open, I can see a situation where pressure could build in the boiler and force boiler water back into the returns...
@ October 4, 2013 12:44 PM in Boiler Sizingthose are tiny radiators, if my vision doesn't fail me. Your calculations for EDR may be pretty close! Great.
In which case, however, your boiler is wildly oversized. Double check everything, but then try to get a boiler which comes very close, in EDR rating, to your real numbers. You'll be much happier and so will your steam system.
@ October 3, 2013 9:34 PM in Boiler Sizingwith your EDR figures, I think. As NBC says, the EDR of a radiator is the effective radiating surface area of the unit -- not the face area. Even a very small (5 section) typical radiator has an EDR of about 18; most normal radiators are around 40 to 50. Big ones can easily go twice that (I have three which are over 100 each). Your calculations work out to an EDR of only 15 for each radiator!
Much the easiest way to figure boiler size is directly with the total system EDR, as the boiler ratings for EDR have pickup and other odd factors built in.
Let us know how your recalculation goes!
@ October 2, 2013 5:51 PM in Overhead radiant heaterthat my first thought would be the dump. That is an old heater, of its kind, and if it is developing cracks they aren't likely to stop -- you can't fix them with furnace cement or anything of the sort; the only fix is a competent welding job -- which would likely cost as much as a new one.
The real problem with cracks is that they disrupt the combustion, as you have found out. The problem with that is that it is quite possible for carbon monoxide to form as a result, and get into the heated space where you are. Carbon monoxide is not nice stuff. It will kill you.
As I say, my thought would be to say goodbye to the old faithful beast, and get a new one.
@ September 30, 2013 12:34 PM in Need help with and old coal furnace converted to a natural gas radiant heatlooked too fast, or too little, or something.
Bet she'll get that system singing along as it should, though!
@ September 30, 2013 11:36 AM in Radiator Valves: Full Port?The critical thing about a radiator valve on a one pipe system isn't so much the size of the opening -- although it surely must be big enough -- but is that condensate must be able to drain freely and completely out of the radiator. Otherwise it will either burble happily at you, which you may not want... or even not heat well, because the steam is blocked by the condensate trying to get out.
@ September 30, 2013 11:34 AM in Need help with and old coal furnace converted to a natural gas radiant heatOh boy. Not sure we have any experts in those parts -- but anyone who is a single mother and has the ability to live there should be able to figure out -- with some help from all of us -- what to do next, and how to do it.
Don't be afraid to ask questions. There is not such thing as a stupid question. We will try to avoid stupid answers, though.
The whole process may take a while, though -- patience.
Do get Dan's books -- there is a nice set of them available from the "shop" tab here, and they are well worth the money.
When you need new bits -- and it is likely that you will -- we may be able to recommend which ones, and, perhaps more important, where to get them. There is no future in taking the time to install poor quality fittings and, unfortunately, that is all that tends to be available in the big box stores.
NBC has given you a nice start with seeing if you can clean up one vent and seeing how that goes. What he didn't mention is that when you hold it vertically -- as he suggested --- and try to blow through it, you should be able to. I might also add that if the soap and water and shake treatment doesn't free it up, you might try repeating it, only with vinegar and letting it soak for a bit, then rinsing it again and trying again.
@ September 29, 2013 7:25 PM in Radiator Valves: Full Port?where a valve restriction doesn't make a whole lot of difference is in a radiator feed valve; the weird condensation from the expansion after a restriction is going to happen in the radiator, where you want it to! Consider: a lot of vapour systems use either orifices or adjustable (e.g. Hoffman) port valves anyway.
That said, it might be that the valve will act like a too small orifice; you'll find out quickly enough if the radiator doesn't heat across.
I presume, of course, that all this is two pipe or vapour?