Delayed condensate returns

25 gallons a day is still a lot of water. You don't want to rot out a new boiler.

Water can only exixt as water or steam (no ice in this example) so you need to be on the lookout for water or steam. A water leak is usually easier to find a stem leak may not be visible.

Packing nuts on radiator valves, air vents leaking, buried wet returns, the vent and overflow pipes on your feed tank are all places to check.

You mentioned " Delayed condensate returns " and " We now are at 3 gallons of water per cycle 25 gallons per day ".

Presently if runs one cycle and it adds 3 gallons, then shut it down, does the 3 gallons eventually come back or does it just disappear forever ?

How do you know that you are using 3 gallons of water each cycle; how do you know this and how are you measuring it? As all the other guys have said, 25 GPD indicates either a steam leak, condensate leak, or water flowing out of the tank overflow. By the way, what size condensate return tank did you install, and where is the make up float level set.

I feel like the assessment may be off base.

"buried returns"

"Also now the cycles are shorter as the weather is warmer"

If you change 2 things at the same time it can be darn near impossible to asses which change fixed the problem. The tank should have never been added, the leak should have been found first, it's there, you haven't found it yet. If, by the way I read it, you added the tank around the same time as the cycles cut down, you may not have actually reduced any usage, the leak just doesn't have as much opportunity to present itself. 2 things at once, tank add and cycles shortened. You have decided the tank fixed something, I say no way.

Buried return would likely have a vertical at both ends so it's effectively a trap and will only leak what is in it. Short cycles put less water into the return, hence less water usage.

A boiler feed tank is incapable of fixing a water usage issue. I'm really not sure how anyone has decided it fixed anything with the information supplied. It's a tank that holds water. Water usage in a steam system is 100% the water escaping as either liquid, or gas (steam or evaporation), that's it. A tank just adds volume, it can't stop water from exiting.

I agree with others, that usage is insane and you have a leak. You need to go find that leak.

If we have a leak why aren't we using the same 16 gallons being fed through the automatic feeder plus the 2.5 being fed now. Instead total city water consumption has been reduced with the feed pump to now about 2.5 gallons per cycle.

If you don't have a leak, where is 2.5 gallons going every cycle?

This was added to a small boiler that had a lot of steam main but was reduced from about 18 rads down to 4….building is now storage.

It is welded up from the salvaged 6" header from the replaced 1955 boiler.

Old header was in excellent condition BTY.

This gives you an extension of the boiler that has no fire under it.

Slow condensate return was a concern as there is 165' of 4" main with 2 1/2" return.

You can see that return was reduced to 1" copper at the boiler…..we had more CI piping than radiators. Boiler is a 63-04 which contains only 10.8 gallons.

So we have not run out of water in the boiler with this tank added.

Your tank didn't stop you from losing water the warm weather did.

I'm not sure where you're located but here it was quite cold the past few days, how did your system do?

If I was you I'd start looking at packing nuts and radiator vents.

Picture two buildings with the same heat loss the same boiler and the same amount of pipe and the same radiation same square footage.

Building 1 is 6 stories high, Building 2 is 2 stories high.

I appreciate what you're saying, but how could both of those buildings have the same amount of pipe (pickup factor)? And even in the taller building, not all the radiation is on the top floor—the differential isn't as massive as one might imagine. But I'm kind of talking about something I don't know about I admit. I wish I was the boiler operator of a 20 story steam building. If I lose my current software job I might seek out a trades position.

if we knew the total cu footage of the OP's system it would be easy to calculate, but it strains my credulity to think that at 1700 times the water volume he is actually running out of water to make steam. I'd much quicker suspect surging.

@ethicalpaul

Don't forget the boiler that @JUGHNE is talking about is a 63-04 and holds 10.8 gallons of water.

But you can't evaporate all of that. How much water does it hold from 1/2 a glass down to the low water cutoff??

If you start off with the feed tank at a normal level again you can only use the water down to the level the MU water adds at.

So you take the boiler and figure out how much water it can eveporate in a min. Find the water volume the boiler holds between 1/2 a glass and when the feed pump comes on and add to that how much the feed tank holds between a normal level and when the mu water comes on.

Thats what you have to work with. 100,000 btu out put boiler will evaporate about 1.72 lbs/min.

I used to use 20 min from starting to steam to when condensate starts to come back. In some cases that is not enough so you go with a bigger feed tank.

@ethicalpaul

Like where is the water going and how did the boiler feed tank help cure part of the problem?

@bayridge you are correct with your assumption, the church I referred to is a two pipe system. I am thinking about your premise that a well functioning two pipe system will lose less water than a similarly sized one pipe system.

On the majority of one pipe systems we service, there are radiator vents that might leak some steam, along with potential leaks on main vents. On older systems (every one we work on) there are also radiator valves that often have packing leaks along with other minor leaks.

On the majority of two pipe systems we service, there are large vents on the condensate stations and the boiler feed stations (typically these vents are 2" pipe open to the atmosphere). If there are bad steam traps (radiator, F&T, and bucket) then these vents might blow like a large tea kettle. Similar to one pipe systems, on the older systems there are radiator valves with packing leaks.

Since ninety nine percent of the steam systems we work on are at least seventy years old, I cannot give you a definitive answer on which system used more water when they were new. I can tell you that the majority of two pipe systems we service are commercial or very large homes. I can also tell you that many of the larger two pipe systems were originally fitted with boilers that had a large water content. Similar to what @JUGHNE posted above.

Did OP ever state how the added water was measured…….actual meter or not?

@RayWohlfarth explains it well in his new video. Substitute his example boiler size with your 100 hp size and other values unique to your system to verify the tank size.

Boiler feed mistakes & sizing
https://youtu.be/mSbpPwHDFwk

" Again the configuration of the building has an effect on tank size. "

@RayWohlfarth's calculations do include that variable. Just change it to what is more factual for that building.

bayridge stated " We have a 38 gallon boiler feed tank "

If I understand the formula correctly and did the math correctly for a 100 HP boiler, if the condensate is not coming back in 5.5 minutes the tank is too small.

Which is probably why the addition of the tank helped but did not totally solve the problem.

Thanks @RayWohlfarth, it all seems to make sense (at least to me) when the due diligence is done.

agree, per the above formula you need a 70 gallon tank for a 100hp boiler with 10 min condensation return time.
The three gallon are going down the drain each cycle due to the undersized tank.

Pretty sure @RayWohlfarth went through this exact problem in another one of his videos.

With a system that big, depending on the pipe size of the returns, even with the guts removed from the trap it still may be a restriction.

I would also wonder why so big a boiler. I am not sure where you are located, but here in Chicago ( 6200 DD65 and design about 0F, with the typical system about 60% oversized radiation), 50,000 sq ft 3 story multi-unit residential buildings from early 1920'a with one pipe steam only need about about 40 HP boilers. We even have one that is only about 30 HP and heats just fine. We did a full radiator load check on all of these buildings. Maybe this is a church with huge radiators? We've never had a boiler run short on water.. close but not quite. We have pulled out old 1 million btu Kewanees and replaced them with 350,000 btu small cast iron sectionals and haven't had a problem.

Something that helps greatly to get the water to return faster is to improve the main venting. The faster the steam gets to the end of the main, the quicker water will begin to return. The water collecting in the bottom of the mains takes a long time to move to the end of the main. Steam moves much quicker. We've eliminated a number of feed tanks and condensate pumps using this method.

I also agree, boiler feed tanks don't eliminate water usage unless the system is overfilling and draining out the main vents at the end of each heating cycle. In a 50,000 sq ft residential building we worked on a number of years ago we found 70 leaks on the system, this is pretty common.