Waterlogged Steam System

LivingTheSteam

Please Help! I will try and make this as brief as possible but there seems to be a lot going on. I have brought in my local HVAC company and I haven't been able to get any straight answers or resolutions.

I purchased this house this summer and was told it had hot water heat. It didn't take me long to learn, literally like 3 days after owning, that I in fact had a steam heating system. The system consists if 2 different boilers, oil and coal, and a rigged up condesate tank, dual pump. The dual pump system is wired up so that if the coal boiler is running and asking for water the one pump turns in and pumps it back. The other pump does the same for the oil furnace.

I have done a lot of reading on the forums and other steam related articles and my HVAC company keeps telling me I have to have traps somewhere at each radiator. He only steam traps I have found are on the 2 main returns right before the condensate tank. It is a 2 pipe steam radiator system, so I am led to believe the trapping of the steam happens in the radiator or in the "simple looking" 90 degree elbow out of the bottom of the radiator.

The overall issue is that the system seems to me to be getting waterlogged. Currently I am running the oil furnace. When the oil furnace first starts the water level in the sight glass is at about 1/4 from the bottom. After the thermostats get satisfied and the boiler quits running for an extended period of time the sight glass slowly rises until the water level is literally filling the entire site glass up after about 30 minutes. I've talked to my HVAC about this and they say ti just let it run, eventhough the first time I had them here they told me to always make sure the water level is in between the sight glass, I don't think they have the answers. If I don't di anything and let it run. I end up getting alot of water coming out if my control valves at the top of my radiators, and also some leaking from the steam output pipes in the basement, like they seem to have water in them. It is a larger home and has long runs, so I wonder if when the system shuts down that steam in the pipes turns back to water and the is getting back fed into the boiler. Depending on how long it has run since I blow the boiler down u can get 12-15 5 gallon buckets if water out of the boiler before the water level even begins to go down in the sight glass.

I am attaching photos of the radiators, if someone can give me any thoughts on why nk steam traps that would be a huge help.

Also, any thoughts on why his is happening. There are several radiators in the house thst the very first time I ran the system I felt begin to get warm, but have not felt them get warm since. Granted I haven't been able to run the heat for extended periods of time to this point because I had a leak on my oil boiler at the domestic coil which has now been replaced, this was something I was also hoping would solve my water issue as maybe there was a hole in the coil, but apparently not.

Any advice, thoughts, things to try, would be helpful. If you need any more info please ask.

LivingTheSteam

After some removing some of the paint on one of the radiators, it says Union Radiator Johnstown. Not sure if that is helpful in determining if there should be traps or not.

EBEBRATT-Ed

no traps on the radiators and none needed. this is a vapor system that has been botched up. I would order dan's book "lost art of steam heat" available on this site.

normally you shouldn't need the condensate pump or traps although adding the wood boiler complicates the whole thing you probably have unequal waterlines

But I will let others more knowledgeable on vapor comment @Jamie Hall & @Steamhead

LivingTheSteam

@EBEBRATT-Ed Just out of curiosity, what leads you to believe it is a vapor system as opposed to a steam system?

KC_Jones

LivingTheSteam said:

@EBEBRATT-Ed Just out of curiosity, what leads you to believe it is a vapor system as opposed to a steam system?

It's a 2 pipe system. Those were all run at very low pressure and referred to as vapor systems. It's still steam. When I say low, like 8 ounces or less typically. If the boiler is oversized you'd need a vaporstat to keep it that low. I'd speculate it's oversized, seems like all the ones posted here are.

I'd agree with some of the above, look at the return piping, how does it's height relate to the boiler waterline. If you have at least 28" you shouldn't need the tank and pump at all and not having it would simplify things dramatically.

Something is adding water into the system for you to be overfilling like that. Need to look at how it's connected to the water line of the house and if it has an autofeeder or not. Could be a valve leaking by, or a bad feeder, or bad control on the feeder.

Hopefully @Steamhead chimes in with some info on the system. I see Detroit on the one valve and I'm pretty sure he's mentioned that one before.

LivingTheSteam

@KC_Jones I should add the oil boiler system does have an auto-feed installed on it as well. It calls for water from the condesate pump, which also has a float on it that when the water drops below a certain threshold in the condesate pump it will add more water from the domestic water.

homers

Im not a heating tech but if its filling, i would shut all water off on the system and make sure radiators are all empty as well. I have a 1 pipe system so its a bit different and is the only experience i have. But i would think the principal of operations would be the same

Long Beach Ed

When two boilers are used, care must be taken by the installer to control the waterline of the boilers. Your condensate pump does this.

There appears to be a toggle switch that may control the condensate pump's application. In conjunction with a low water switch, this appears to choose the boiler which is fed and control the amount of water added.

Most condensate from the radiators returns to the receiver tank. Some, however, may find its way back to the boiler through the header. The condensate may overfill one or both boilers. Usually the boiler that is turned off overfills because it has the least pressure of the two. Steamfitters usually install water level traps on dual boilers to avoid overfilling. Your system does not do this.

It's assumed that the system worked well at some point, so I must agree with Mr. Jones' assessment that you must find out what controls the condensate pump (which is acting as a boiler feed pump). Is it an adapted low water cut-off control? Something controls the amount of water fed to the boiler. You must seek out what it is and why it's overactive.

Ed questions the need for a condensate pump, a question with which I concur. Once this system is rectified, it would be interesting to see if the design can be modified to eliminate the pump, simplifying the operation and making it more economical.

JUGHNE

The coal burner looks to have some pump for maybe baseboard heating.
Does the oil burner have the same connections?

LivingTheSteam

@Long Beach Ed that has been my issue to this point. I have had the only HVAC in my area that says they do steam and they don't have the answers and already cost me a lot of money changing parts. You are correct, the condesate tank has 2 pumps on it. Each pump is wired up to a low water auto feed on each individual boiler. When the coal furnace is running and needs water it pumps the coal condesate pump and the oil does the same. I have assumed through all of this that it seemed like what was missing was some type of overflow (what you called an overflow trap) to not allow the boiler to get flooded. I think what is happening is that the steam line is actually getting flooded with water and pushing water out the radiator (had a loose packing nut which was causing the water to flow put like a spring from the control valve and I had just got a leak on a pipe there wasn't previously a leak on the steam line, which I think was because there was water in the steam lines.)

LivingTheSteam

@KC_Jones the return, "add water to the boiler line" actually comes from the ceiling height after it is pumped from the condesate pump on the floor. Pump pushed it up and then it comes across the basement into the boiler. I have attached a photo of that pipe.

Also, how do I know if my boiler is oversized, I have attached a photo of the tag of the oil boiler.


The other thing is, and maybe not an issue at all but just something of note because it seems off to me, but I don't know anything. When my boiler is running it builds to about 6psi (according to the guage) and then will shut down until it gets back to
3, and then run to 6. This process is in about 3 minute intervals once it gets initially to 6 then it will shut off foe 3 minutes down to 3 and then run fie 3 minutes back to 6 and so on...it seems off to me but maybe not.

I have also attached pictures of the condesate tank and individual pumps for the oil and coal boilers, and a picture of the float device on the condesate tank that is hooked up to the domestic water if it needs to add water to the system, ie.if the condesate return isn't enough to feed the boiler.)

Also, I have noticed that there is Hoffman No. 8 valve on a radiator up in the attic. The only trap like that on any of the radiators?

KC_Jones

I'd start with turning off all water feed valves no matter where they are. Something is calling for fresh water when it should not.

Sounds like it could be the tank float set incorrectly.

If the contractor comes back I would push them for guaranteed fixes, I'll bet you find they actually know nothing or close to nothing.

You'd be surprised how much diagnosis can be done remotely on this site, hopefully the right people chime in, I am far from an expert on 2 pipe. The basics of any steam system are fairly straightforward though.

LivingTheSteam

After I completely blew the system down of all water and waited about 5 hours. I put the power back on to the autofeed pump and it filled the boiler back up to this level and shut back down. I have not fired it back up yet, will do that later, but I know from past experience after it runs the water level will be above the site glass. It takes about 30 minutes but it will slowly rise until its above the sight glass.

KC_Jones

The question of whether you need the tank relates to the lines feeding into the tank from the radiators and how the height of that pipe relates to the water line of the boiler. If those lines are roughly 28" above the water line the tank and all it's accessories aren't necessary.

We've seen this a bunch on here, contractor sees steam and assumes they need a tank and adds one as a "fix". I'm not saying it's your situation, but actually needing a tank in a residential application is somewhat unusual.

Turn off the water feed to the tank, if the level is still rising, then see if there is a feed for the domestic coil feeding the hot water loop and shut that off. If that stops it you have a leak in the coil and it will need replaced.

JUGHNE

He said he had just replaced the tankless coil. If it leaked wouldn't the boiler over fill even when not running?

Can you show us where the coal boiler connects to the steam system?

And how about the pump and copper lines connected to the coal boiler....are they shared by the oil boiler?

LivingTheSteam

@JUGHNE you are right. On the oil tank boiler they are pulling water out of the boiler, on the domestic coil, which is pumped over to the coal furnace (in case the coal furnace is the one running) and there is a pump that pumps that water up into hot water baseboard heat in an addition that was put on to the house.

LivingTheSteam

LivingTheSteam

@KC_Jones here is a picture above the condesate tank. All return lines I assume with good certainty come here. The traps are above the condesate tank, the picture of the tank sits right belkw the traps and all return lines.
All radiators are on the floor above the boiler so the lines are definitely higher than where the line into the bottom of the boiler is. It is a few rooms over in the basement although. What is the 28" significant that you speak of?

Could the need for the condesate tank and the rigged up dual pump system be because without the pumps you have no way if diverting the water to the correct boiler...but I guess that doesn't make sense you could just do it with some open and closed valves.

Eliminating the tank and pumps would be a huge win because that is where all my issues actually started. I wanted to run my coal furnace but the pump on the condesate tank that fed the coal furnace went bad. I had to get it rebuilt because the pump itself is not made anymore and the bolt pattern was unique to that pump so if I didn't rebuild it I was told I would need to get a welder to retrofit a new bolt pattern pump onto the tank.

I still haven't got that coal furnace fired due to some other furnace issues. I'm sure I'll have a bunch of steam related issue with that too, as my luck has gone with this.

JUGHNE

When you open the yellow handle blow down valve on the M&M 67, does the burner stop and a pump start?

Is it the right pump for the oil boiler?

Can you back up for pictures of the piping?
Especially around the pipes on the pump/tank.

Floor to ceiling is the best shot to figure what goes where.

LivingTheSteam

I assume that if I shut the power down to the Auto feed, if the boiler water level is drops too low then the boiler will just shut down? As long as the water level stays about where it is in the sight glass just let it run and see how not reacts after it has the thermostats satisfied?

Jamie Hall

Oh dear me. Well, first, yes that is -- or was -- a vapour steam system. Vapour systems are a type of two pipe steam system which runs on very low pressure -- usually not more than 8 ounces (that's OUNCES) per square inch. If they are run on the correct pressure, there is no need for any traps on the radiators. as the inlet valves are set -- or can be set -- so that only as much steam as the radiator can condense is allowed in.

Your running pressures are far too high -- in fact, about 16 times what they should be. This is going to cause all kinds of mischief, and it will be difficult to determine what other problems you have until you get that under control. The oil boiler must be controlled by a Vaporstat (tm), not a pressuretrol, which will need to be installed and connected. The pressuretrol can be left as a safety backup.

The coal boiler is going to be a problem, no matter how it is piped in, as it is very unlikely that there is a control on it which will keep the pressure in line. Coal fired vapour systems all had, in addition to a pressure sensitive draught control, any one of a variety of interesting arrangements to ensure that the pressure difference between the steam mains and the returns never got too high. The existence of the condensate receiver defeats that completely, even if one is still on the system.

Now it would seem that at some point someone got enthusiastic and put in a condensate receiver. That's neither needed nor wanted, and causes problems even when it's done right. The first thing to check is just what does turn the pump on. If it's the float in the tank, it will never be right. That float -- assuming you don't take the whole thing out as part of getting the system to work properly -- must be controlled by the boiler water level, not the condensate tank level. The float in the condensate tank should only control the makeup water feed. If you do have that arrangement, there should be no other source of makeup water for the boiler. It's possible that your low water cutoff is wired to control that pump (the writing next to it suggests that that is the case).

The excess water problem may simply be that the pressure is so much too high. Or it could be that there is some other water supply. Without watching the system in action, I can only guess that what is happening is that the pressure is forcing water out into the system (up as high as the second story, with that much pressure) and the combination of the feed pump and the feed to the condensate tank senses low water and adds more water. For this reason I would be very cautious about operating the system with the feed to the condensate shut off until you can get the pressure under control.

Where is this located? You really need someone who understands steam to come and rework the system.

Jamie Hall

LivingTheSteam said:

I assume that if I shut the power down to the Auto feed, if the boiler water level is drops too low then the boiler will just shut down? As long as the water level stays about where it is in the sight glass just let it run and see how not reacts after it has the thermostats satisfied?

See my comment above. Yes, you could try that, and if should, but only if you or some other competent individual is there watching the sight glass and prepared to shut off the boiler if the water drops to near the sight glass. Don't leave the boiler while it is running for even a minute. If the boiler goes dry you are going to be in a world of hurt.

Long Beach Ed

Naturally there are several things that could be wrong. Let's look at how the boiler feeding is controlled. The boiler needs water. The dropping water level called the feed pump to feed water up to the normal water level, which it does.

The boiler steams and the water level drops more as steam leaves the boiler. The feed switch drops and more water is fed into the boiler by the pump. The condensate begins returning. If it returns to the receiver, all is fine. If the system was not designed for a receiver, some of the returning condensate may return directly to the boiler(s) via the steam header. If that's the case, the boiler will now be flooded.

If that is the case, there are several ways this can be corrected. The system can be returned to a gravity-return system and the pump eliminated, as both Ed and Mr. Jones is discussing. This will take some engineering. Or overflow traps can be added to each boiler at the water line to return excess water to the receiver.

Another possibility is that the boiler is being overfed. Perhaps a feed pump is being directed by a "low water cutoff" that has a delay or over-feed circuit that is incorrectly set and feeds in excess over the desired level.

Lastly, your boiler may be getting water pushed into it from the other boiler. When you are using the oil boiler, steam pressure is being exerted on the surface of the water in the wood boiler. That will push down on the boiler water causing the water in the wood boiler's return to rise out of the wood boiler. Depending on how this is piped, it may spill into the return of the oil boiler raising its level. You have to follow the piping, look for pipes that will equalize pressure between the headers and the returns and Think like steam.

... I notice a valve (King Valve) atop one boiler. If both of the boilers have these valves on their headers, I suspect that you are expected to close the valve on the unused boiler to prevent system pressure from exerting on its surface water and pushing water out of its return.

Lastly, you can have a bad trap, check valve, feeder, feed switch or hot water coil (which was probably needlessly replaced).

I hope this offers some ideas for thought.

LivingTheSteam

@Jamie Hall I am in Johsntown, Pennsylvania.

LivingTheSteam

@Jamie Hall the other part I don't understand is that this house was occupied. The people lived here for 30+ years and when it was sold never mentioned any issues with the heating.

LivingTheSteam

@Jamie Hall
If it's the float in the tank, it will never be right. That float -- assuming you don't take the whole thing out as part of getting the system to work properly -- must be controlled by the boiler water level, not the condensate tank level. The float in the condensate tank should only control the makeup water feed. If you do have that arrangement, there should be no other source of makeup water for the boiler. It's possible that your low water cutoff is wired to control that pump (the writing next to it suggests that that is the case).

I am almost positive that this is the case. The float in the condesate tank asks for water to be added to the condesate tank to make up for lost water in the supposed closed system . The mechanism on boiler calls for water from the condesate tank when it drops below a certain level in the boiler.

LivingTheSteam

@Jamie Hall Should the vaporstat replace the circled device? And then what should the vaporstat be set to? I will talk to my HVAC company about making this switch. If I am to understand why this is an issue its because the pressuretrol is allowing the pressure in the boiler to build too high and it is pushing water out into the systen as opposed to steam? With the vaporstat this won't happen?

Jamie Hall

The vaporstat doesn't have to replace the pressuretrol. In fact, I would keep the pressuretrol as a backup safety device. The vaporstat can simple be Teed into the same pigtail, and then wired in series with the pressuretrol. You should have a 0 to 16 ounce vaporstat (there is also a 0 to 4 pound type) and I'd set it to cutout at perhaps 12 ounces and cutin at 4 ounces as a first try.

I can't tell you how the house was run before. Perhaps not very well... sellers don't always tell you everything. It could also be that the pressuretrol setting was changed at some point by someone who didn't know any better.

LivingTheSteam

@Jamie Hall With all that being said, until this can be fixed how would you run the system? Run it as is and blow it down every so often? adjust the pressuretrol?

Jamie Hall

I'd valve off the coal boiler completely, set the pressuretrol down as low as you can (probably around 1.5 psi, and really check on when that boiler feed pump comes on. Make sure that water can't get into the boiler in any other way.

Steamhead

LivingTheSteam said:

@KC_Jones here is a picture above the condesate tank. All return lines I assume with good certainty come here. The traps are above the condesate tank, the picture of the tank sits right belkw the traps and all return lines.
All radiators are on the floor above the boiler so the lines are definitely higher than where the line into the bottom of the boiler is. It is a few rooms over in the basement although. What is the 28" significant that you speak of?

Could the need for the condesate tank and the rigged up dual pump system be because without the pumps you have no way if diverting the water to the correct boiler...but I guess that doesn't make sense you could just do it with some open and closed valves.

Eliminating the tank and pumps would be a huge win because that is where all my issues actually started. I wanted to run my coal furnace but the pump on the condesate tank that fed the coal furnace went bad. I had to get it rebuilt because the pump itself is not made anymore and the bolt pattern was unique to that pump so if I didn't rebuild it I was told I would need to get a welder to retrofit a new bolt pattern pump onto the tank.

I still haven't got that coal furnace fired due to some other furnace issues. I'm sure I'll have a bunch of steam related issue with that too, as my luck has gone with this.

@LivingTheSteam , in the pic showing the two F&T traps, is the left one connected to the dry (overhead) return line from the radiators?

LivingTheSteam

@Jamie Hall so I turned the pressuretrol down and I did have some issues at first with it not shutting off like I expected so I took the pressuretrol off and cleaned out the pig tail. After installing it and running it again the system now shuts off as i would expect when the pressure is reached.


Here is 2 interesting things to note. After only running for about 4 minutes the system reached the high pressure and shut down..is that normal for the furnace to only run that long?

Also, after almost every cycle, a few seconds after the furnace shuts down the Auto fill pump kicks on and adds more water to the system (pump this triggered for about 3 seconds).

Not sure why when the pressure is reached and the furnace shuts down does the system calls for more water.

LivingTheSteam

@Steamhead yes, the left one is connected to the dry return lines.

mattmia2

There are about 6 things here that whoever worked on this didn't understand.

Those valves with the lever handles are special valves that when fed with a few ounces of steam pressure only allow as much steam in to the radiator as the radiator can condense so the steam doesn't get in to the return, they don't need traps if set up properly. The radiators where someone has replaced the valve need either orifice plates or steam traps. The trap on the return is a misguided attempt to fix this.

The mains should connect to the returns either through traps or below the water line. either the mains need to vent through the returns through the crossover trap or the mains need to have vents. in 2 pipe systems the radiators vent through the returns so the returns need to be vented somehow.

Long Beach Ed

So now we know why the boiler is overfilling. Hard to imagine that it runs low on water after four minutes of steaming. Is that water being lost as steam up the steam mains? Or is it being pushed out of the returns into the other boiler or the receiver?

You'll have to examine the piping and figure this out. Make sure the pressuretrol is working and set somewhere low as mentioned by Mr. Hall.

Obviously, after the boiler feeds again, this lost water is returning and flooding the boiler. Deal with that and then you can get to work on the issues Matt mentions and figure if and how you can eliminate the pumps and receiver if you like.

LivingTheSteam

The players that are involved in the autofeed are a Mcdonnel & Miller Low Water Cut Off, a Honeywell Switching Control Transformer Relay RA89A, and then the pump on the condesate tank.

When observing this, the LED Light on the Low Water Cut Off doesn't actually light up but the honeywell relay switch opens and the pump kicks on and adds water. I know the LED light could be bad in the Low Water unit but something I took note of. Tracing the wires there is only one other thing directly tied into the Honeywell and that is some device attached to the end of my blowdown which is a Mcdonnel No 57 Low Water Cut Off

As I typed this I watched it again. After the cycle ends, about 10 seconds later the Honeywell control opens and more water is added.

LivingTheSteam

I took 2 videos

- This video just shows the water bounce in the sight glass during operation, from everything I've seen on here it seems normal.
-
https://drive.google.com/file/d/1164eKKgiIA_Ql8roCAbDDkQqtTVkoTpX/view?usp=drivesdk

- This video, if you go around the 55 second mark, you will see in the top right hand corner the gray honeywell will open up and then you will hear the pump kick on to add water. What is interesting is that the water in the sight glass does go down close to the bottom before it kicks on. So maybe it isn't an issue with the devices, but more with as soon as the cycle stops why or where does the water get releases to? This doesn't happen after every cycle, but it seems to happen after most.

https://drive.google.com/file/d/11A4fCWGeKQ3TZMcwlFslQsCC7r2r793v/view?usp=drivesdk

Jamie Hall

Has that float type low water cutoff been cleaned lately -- the McDonnell Milelr 67? It needs to be blown down from time to time to make sure the float is free.

I would be willing to bet that it, not the probe type one, is what is controlling that pesky feed pump. The type 67 has two sets of contacts -- the feed contacts close first on a drop on water level, and the cutoff contacts open with slightly more drop.

The existence of the tank and pump makes things more complicated than they need to be -- but in any case, what should NOT happen is that there should not be any additional makeup water added, and the boiler feed pump should run only long enough to bring the water level in the boiler back to where it should be.

The four minute cycle is shorter than it should be. However, there are two reasons why it might be: first, the main venting could be bad or nonexistent, which I rather suspect is the case. Second, though, are you quite sure that it is the pressuretrol cutting off the cycle, or is it the MM 67 on its idea of low water? You haven't mentioned it as a player, but it's wired in and doing something and you need to find out what. If it's the venting, we can fix that later after we get the water levels straightened out.

Long Beach Ed

Jamie is right. The controls are probably working fine, but that much water shouldn't be leaving the boiler so quickly. Did you close any valve atop the coal boiler?

The 67 control may be running the pump. If it's doing that job, it's not the proper control to operate a feed pump and its switch will not last in that type of service.

LivingTheSteam

@Long Beach Ed I have made sure the valve above the coal boiler is closed as well as felt the steam lines that go towards the coal boiler, they are not warm in to the coal boiler past the valve but as it is piped to sometimes use the steam from the coal boiler the pipes feeding the rest if the house around the coal boiler are hot.

@Jamie Hall I have definitely used the no 67 device as that is how I blow the boiler down whenever it gets to full of water, normally when I shut the system down, or a thermostat is satisfied and it doesn't need to run for a few hours is when the water level rises. The boiler has been running on that 4 minute cycle for the past 5 hours and the water level is still fine in the boiler (usually becomes an issue when it's not running).

When the water level does rise I need to shut the power off at the pump and also on the front of the boiler so that when I use the 67 to blow the water down it doesn't keep filling it back up. I have tested it before where I leave everything on and blow it down and it immediately calls for more water.

I also am 95% sure that it is the pressuretrol that is controlling the turning on and off of the boiler because before I turned it down it was consistent when it would kick off and come back on. Since I have turned the pressutrol down like you recommended it is still consistent on cutting out and coming back in but just at a lower pressure.

LivingTheSteam

Along with the issue if the water continously getting added ti the system I also have about 75% of my radiators that are not getting hot at all, in fact the pipe running up into the radiator is not getting hot either.

I just traced both the feeds and the returns of the entire loop and there is nothing one any return, nothing on any feed that resembles any kind of vent or any kind of trap other than at the very end of the run.

Every return looks like this


And the return and main steam feed end right above the condesate pump at the steam traps which I have learned to be F&T Armstrong 15-B3 C-1020 Steam Traps



That's it, that is my system. It doesn't get hot in over half the radiators and water gets added after about every short 4 minute cycle.

I am at a lose of what to do as winter in Pennsylvania is setting in and this isn't providing heat.