Joined on September 16, 2002
Last Post on December 12, 2013
@ December 12, 2013 9:15 PM in Boiler pressurebut I can think of at least one possibility. If the expansion tank is really waterlogged or failed, when the system cools to 130 the water contracts and the pressure drops -- if the pressure drops enough, it could even pull a vacuum. Either way, air -- or water if there is a feed from the domestic line attached -- will get in there and replace the volume. Now when it heats up, it all tries to expand and there's nowhere for it to go, so poof goes the relief valve. But if it only has cooled to say 180 or so it doesn't contract as much, so it the pressure doesn't drop to pull in a little water or air...
@ December 12, 2013 9:10 PM in No return and banging pipesa one pipe or two pipe system? It makes a difference...
If I assume it was a one pipe system, and you removed the return pipe or pipes, and you didn't re-pitch all the mains, you have a problem Possibly a big problem.
Originally all the mains would have been pitched to those returns. Condensate from the pipes and the radiators would flow along the pipes to the returns, then through the returns back to the boiler. With the returns gone, that water has to find another way back to the boiler, which it apparently can't do easily (that's your overfilling problem). Furthermore, while it's trying to get back to the boiler, the steam is trying to get out to the radiators, and they fight. That's you water hammer problem.
OK. If all that is so, and you can't restore the mains they way they were -- and should be -- the solution is to re-pipe all the mains as counterflow mains. This may mean simply re-ptiching them all so that they can drain to a return to the boiler right near the boiler and modifying the near boiler piping to suit. However, if they were parallel flow -- that is the returns were at or near the ends of the mains -- you may have to not only repitch them to flow towards the boiler rather than away, but replace them with one pipe size larger.
Or, of course, you could put things back the way they were intended to be before your plumber got after them.
Either way, I doubt very much if it is a suitable job for a homeowner, and I regret to say that it does not sound like a suitable job for the plumber you reference. You might look under Find a Contractor -- look by State, not zip code -- to see if there is a good steam contractor nearby who could help you out.
@ December 11, 2013 8:21 PM in help with installing honeywell th8320wf on 2 wire hot water heating systemon the main wall -- but since Dan put it up on off the wall... that will help!
On a hot water system, the thermostat controls the circulating pump or zone valve, depending on the system. An aquastat controls the boiler.
For that Honeywell, you will have to find a 24v constant on terminal on the system somewhere, and hook up the thermostat with all three wires.
@ December 11, 2013 8:18 PM in Keeping circulators always on in unattended home to prevent freeze damageDon't play games.
As noted, a constant circ will work -- unless it's really cold and the boiler is off. Then it won't.
A nice internet base warning system will tell you that your house is going to freeze, assuming that the power is still on and the internet connection still works. Then what are you going to do about it?
Antifreeze will keep your system from freezing, which can cause enough damage to make the house a total loss. Believe me, I've seen it happen.
I'll grant you that working on a system which has antifreeze is tiresome. That, however, is no excuse.
@ December 11, 2013 2:40 PM in How To Find Leaks In Condensate PipesAliga and steamedchicago have very good suggestions. Particularly Aliga's idea of using a video snake to inspect the piping -- assuming that there is a handy hole you can slip it into (and they will get into very small holes -- maybe even where the pipes go through the floor there might be enough clearance).
I'd be rather wary of the idea of a return freezing and bursting -- there is so little condensate that it would be rather extreme, in my view, for that to happen (that said, I have had a trap on a radiator freeze, but not the return -- so never say never!). I'd be much more suspicious of a leak at a fitting; an ideal candidate would be at the bottom of a 90 degree el where it goes into the horizontal line in the ceiling.
All of which finds the leak -- maybe -- but doesn't address fixing it.
Depending on access and exactly how the lines are routed, the best plan might be to abandon the line in question in place, and run a new line -- but without actually looking at the whole setup, I couldn't say whether that was feasible or not, or whether it would even be an improvement over attempting a repair.
I might add that, in my humble opinion, if you have to start tearing things up to get at the horizontal section of the line you should consider what craftsmen -- and I do mean craftsmen! -- you can find. It isn't particularly easy to tear up and replace hardwood floor. On the other hand, finding a plasterer who can patch a plaster ceiling so you don't see it borders on the impossible (although it happens that I do know a chap who can).
@ December 11, 2013 2:27 PM in Banging in pipesany of several possibilities.
Check the pitch of each section of pipe very carefully. Each section must be pitched to drain -- either to the riser, in the case of a feed line, or to the return, in the case of the return line. Even a relatively short piece of pipe, if pitched the wrong way, can cause a really bad water hammer.
Second, check the pitch of the runouts (both feed and return) from the steam main, if these radiators have them. In the process of repiping, it is possible that they were allowed to droop and thus collect water. They too must be pitched correctly.
In both locations you are looking for anywhere that water could pool, even a small amount.
The other large group of possibilities is that you could be having a problem with expansion noises -- as the steam pipes expand, they lengthen, and if they rub on something or try to push the radiators around, they will bang.
@ December 10, 2013 5:27 PM in How do I know my main vent is workingto tell if a vent is actually venting -- you'd think it would be easy, but it's not.
What you can try, though, is a strip of tissue paper -- bathroom tissue is fine. Hold it at one end with the other end right near the vent opening. When the system starts to make steam, it should at least wiggle. If not, chances are you are right -- the vent isn't opening, or not opening enough.
Sometimes you can clean them -- I've heard vinegar works well enough. Sometimes you can't.
@ December 10, 2013 12:40 PM in Oversized Boiler? Or inappropriate location for pressuretrol?with absolutely no guarantee that either one will work...
First, is there a way you can put one of the pressuretrols on the steam main itself? Or even (not as good) on the riser? That way it will be reading the real pressure in the system, which may not fluctuate quite so much. That one should be the controlling one -- set to perhaps 2 psi max. The other one should be the backup set to perhaps around 5 psi or so.
Then you can also put a pressure snubber on the pigtail to the controlling pressuretrol (make sure it's steam rated). That can sometimes work wonders.
Of course, if the boiler is really seriously oversized, there isn't much of anything that will help!
@ December 9, 2013 11:53 AM in Whistling and hissing radiators after "maintenance"that that's a picture of your pressuretrol, it really isn't that much too high -- but it is too high. Try turning the main down to 2 (much lower is tricky on a pressuretrol) You can leave the differential alone.
The whistling hissing radiator vents suggest to me that they are doing more of the work than they should have to -- and that your main vents aren't doing what they should. What are your main vents? And the sizes of the mains? The idea is to vent the mains as fast as possible, and then use the radiator vents to allow reasonable steam to the radiators.
@ December 8, 2013 4:34 PM in Probably a question you are asked alot..Charles is one of the best -- and I know he will do central Vermont. He may be pretty busy these days, but he'll make time.
And the best of it is that he will work with you -- and you will learn a lot! Give him a ring.
@ December 7, 2013 12:12 PM in Probably a question you are asked alot..I am somewhat sympathetic to some aspects of rjb's comments -- particularly in two regards: one can get seriously hurt, or create a potential for rather expensive property damage, through improper plumbing, heating, electrical, burner, etc. installation and maintenance practices. No question at all. Second, that there is the very real potential for liability.
Before I go further, let me point out that I myself am not a "professional" in any of these trades -- I have never held anything beyond a journeyman's license in them (all of them, though, I might add). What I do and who I am is, I think, reasonably well explained in my signature line.
All that said, though, I would add a few other comments. First, that a goodly fraction of the really horrible knucklehead jobs I have come across have been perpetrated by licensed professionals who were operating outside their areas of expertise; one of the most important aspects of doing work, or offering advice, is to have a very clear understanding and acceptance of what one does or does not know. Second, I have also come across some really superb work done by non-professionals (as well, obviously, as some of the professionals who help on The Wall). Third, it would appear that the OP is, in fact, a professional who would like to understand steam systems a little better and expand his knowledge and abilities, which I think is marvelous.
The potential for liability problem is very real indeed, unfortunately, but it is not confined to heating or indeed any of the building trades. Rather it is a very sad commentary on our society as a whole that we are, as a group, afraid to help our neighbours and others in need because we are concerned that some greedy lawyer and "victim" of our help will sue us. The lesson we are to learn, it would appear, is that if we see someone in trouble, or asking for help, we should pass by on the other side.
@ December 7, 2013 11:20 AM in Clarification on steam boiler sizingIf you leave those steam mains uninsulated, they are NOT included in the pickup factor, and MUST be included in the total EDR for sizing your boiler.
I am not in favour of using uninsulated steam mains to heat a space; doing so tends to lead to poorer steam distribution and slower heat elsewhere, if nothing else. If you do go this route, be aware that there will be a lot of condensate in those mains; you need to size and slope them as though they are one pipe steam, either counterflow or parallel flow as the case may be, with the total EDR of the pipe connected at the worst possible end of the line (far end for counterflow, near end for parallel), and be generous on the sizing -- if it were I and I had to do that, I'd go one pipe size up from whatever the calculations suggested I needed to use.
@ December 7, 2013 11:13 AM in Puzzler: Condensate Return Leak, LWCO, Auto Feederthat something is slightly amiss with the controls (as well as the leak, patience). In my view, either low water cut off should shut off the system, and it shouldn't run at all until both are happy. The behaviour you describe, where it will turn on when the probe type unit is satisfied, even though the float unit isn't, and the water feeder doesn't activate automatically under those conditions, suggests very strongly that the float unit isn't working properly.
It is possible that the vibration of the boiler firing may be enough to allow the float unit to operate properly and activate the feeder, and that the leak is enough so that at night when the boiler isn't firing the water level drops below both LWCOs (the float unit having hung up) and shuts the system down.
They can be cleaned (you do flush it once a week or two, don't you?) but once they start hanging up it is -- in my humble opinion -- better to replace them. This is a safety device, after all...
Now that leak. 2 inches in 2 hours is wildly excessive. Even if you get things fixed so that the boiler will run, that much fresh water is going to corrode that boiler and give you more, and more expensive, problems. Find it and fix it.
@ December 7, 2013 11:03 AM in top floor apartment vents spitting out waterWhat size are these convectors (EDR). Have you checked Lost Art to ensure that the risers/runouts are big enough?
Second -- what vents are you using on the convectors? If the venting is too fast, you can have real problems even if the pipes are big enough with the condensate going back down not being able to get back down -- surprising how fast the steam can move in a riser sometimes, and it can blow the condensate right back up.
@ December 6, 2013 9:43 PM in Pressuretrol settingwhat else was done, besides changing from oil as the heat source to gas?
Just changing the heat source will make no changes in the behaviour of the system.
Something else -- or something elses -- was changed. What? There are too many possibilities to be able to say "try this, try that" (although there was no reason to change the pressuretrol settings).
@ December 6, 2013 6:53 PM in Resources on best testing/setting for single steam pressuretrol setting?other than us -- and our experience. Or Dan's books...
And, based on that, that pressuretrol is set way too high. The main scale should be set at 2 (setting below that can create problems with the linkage -- although it would nice to be able to set it lower) and the diff. (differential) scale should be set at 1.
@ December 6, 2013 12:44 PM in Honeywell Visionpro problemsif these battery powered computer containing whiz-bangs failed to a safe mode on low battery. Sadly, they don't... indeed, I'm not a bit surprised that a low battery could make a VisionPro -- or for that matter any of a number of other devices -- behave quire oddly. Simplest just to change the batteries from time to time!
@ December 5, 2013 8:44 PM in finished basement= trapped vent and cold radiator?why a radiator won't heat -- I presume that this one just isn't heating at all? -- and it is usually best to proceed very very systematically.
You mention that you have opened and closed the radiator valve (from your comment on the radiator vent, I presume that this is one pipe steam -- that is, the steam comes into the radiator through one pipe, at the bottom of one end, and that there is a vent on the radiator about half to two thirds of the way up, and no other pipes?). Remembering "righty tighty, lefty loosey", make sure that it really is open all the way. Sounds obvious, but...
Then, take a look at the vent while the boiler is making steam. Is there any sign of air coming out (may be very hard to tell)? You can check the venting for that radiator if you have a helper: turn the boiler off and remove the vent. While one person keeps an eye on the vent opening (might check and make sure it isn't obstructed) have the other turn the boiler on, but be prepared to turn it off on call. When the boiler starts to make steam and things begin to warm up, if steam can get there at all you should be able to feel air coming out -- and eventually steam. Which will burn badly, so don't get your hand in front of it! And turn the boiler off again.
No air coming out?
OK. Go back down to the basement and start tracing pipes. What you are looking for is finding out how far along the pipe which goes eventually to that radiator steam is getting. It is possible that there is an obstruction somewhere -- which could be as simple as a dip or sag in the pipe.
Does steam get to the radiator, but not into it? Does the pipe to the radiator get hot? If so, there is a chance that the valve itself is broken. It is not unheard of for a valve to fail closed -- you think it is opening, but it is busted inside and doesn't open. But if that is the case, the pipe to the radiator should be getting at least warm, if not hot.
The odd bit of carpentry work in that room does look as though it conceals something; I do wish people wouldn't do that, but they do. Is that more or less directly under that radiator?
I think I'm rambling... but this will do for a start.
@ December 5, 2013 7:21 PM in boiler heat, no heat,no water and some moreBy "metal pipe to the chimney" I would assume that you are referring to the stack connection. That will get hot, make no mistake, when the burner is running. However, it shouldn't gurgle!
What is not clear is whether the boiler is still making steam, or whether it shuts down before it can make steam. However, if there is water in the glass (assuming that the glass is really indicating the water level -- valves open? Connections clean and open?) then there is water in the boiler and, if the burner is running, it will make steam even if there is a good big leak.
Look outside when the boiler is steaming -- do you see considerable white "smoke" out of the chimney? if so, you surely do have a leak, although the lack of "smoke" doesn't mean you don't.
@ December 5, 2013 7:13 PM in ultra low pressure ARCO system maintained at higher pressureis to add a vapourstat, set to cut out at about 12 ounces and cut back in at about 6 ounces. Probably not a bad idea to put a low pressure gauge on, too, to make sure that the vapourstat is properly calibrated. I can't tell you how much money that will save, but it will most assuredly save you money.
I can't imagine where the reluctance to run low pressures is coming from. Nor can I understand the comment that modern boilers are not able to run at lower pressures. Phooey. They do it just fine, all the time.
Yes, it will cycle off on pressure on longer runs. This doesn't hurt anything. It's how they work. It will save you money -- while the boiler isn't running, it isn't burning money.
It sounds as though the maintenance on the system has been let slide enough that fully restoring it is probably not worth the effort. That being so, first repair those traps that the steam blows through. That isn't helping your efficiency a bit, and it shouldn't be that hard to do. At the same time, you will need to add vents at the end of each of the steam mains -- good big ones (there are references on this site to help you size them) and also on any dry returns -- again, good big ones. That will let steam get to all of the system quickly and efficiently at low pressure (it's quicker at low pressure!) which will, again, save you money.
@ December 4, 2013 9:14 PM in Waste Oil Heateranyway, for most purposes (there are slight differences). To watch out for, though:
Some hydraulic and automatic transmission fluids are not petroleum based, and will have very different properties (some are, indeed, essentially fireproof -- intentionally). I have no direct facts, but it seems possible to me that some fully synthetic motor oils may also have rather different heating values.
Another big difference to watch out for is, of course, viscosity, which will affect (sometimes dramatically) the flow rate from a specific nozzle at a specific pressure, leading to potential combustion problems.
And there is a third, but with the type of oils you are looking at it shouldn't be a problem: flashpoint and volatility characteristics.
Some lubricants have metallic compounds (usually molybdenum or lithium) added to enhance their properties under high contact pressure -- I know that some rear axle lubricants do. They might give you problems with ash or coking; I don't know.
@ December 4, 2013 9:06 PM in Need advice on how to go about getting custom controls madeI'm curious, too. As Zman says, a watt is a watt and a BTU a BTU. Thermodynamics is a very unforgiving game, and has tripped many a well meaning person before now... so far as I know, if you have a given space with given thermal loss properties, a certain BTU input will raise the temperature of the space a certain amount -- and it doesn't matter how the BTUs are put in.