uh oh . . .

Erik_M

So with cooler temperatures forecast for this week, I fired up the boiler tonight for a test run.  Mostly I wanted to see how the main vent (more like a sub-main vent, see "Vent AA" in diagram) I replaced this summer held up to live steam.



Roughly 30 minutes into the heating cycle, I noticed that "Main A" was slow to heat.  This mains has always been the slowest to move steam, but this was much longer than usual and the heat seemed to stop in "Main A" just before the intersection with "Main AA".  Could it be that the vent I replaced on "Main AA" was closed and making it air bound?  Even if it was, steam should still be free to move along to the end of "Main A", right?  Then I noticed that the sight glass on the boiler appeared to be full of water (normally about 1/2 full).  So I went ahead and flushed the LWCO.  During flushing, I could see the water level in the sight glass bouncing around near the top of the glass.  After flushing, the sight glass was completely full again.  (keep in mind that I'm not sure if any of this information I've just given you is related to what happens next)



A few minutes later while the system was still heating and I was walking around feeling  "Main A" for heat, I began to hear water dripping.  Suddenly water was spurting out from the fittings around "Vent A" and "Vent B" (see photo).  In the 10 seconds that it took me to figure out what the heck was happening and shut off the boiler, water hammer also started ringing through the pipes in "Main B".  After the boiler was shut off, I swear I could hear water flowing through "Main B" (and God knows what other pipes) for 3-4 minutes.  Fortunately there was never any water spurting from any of our radiator vents.



Now, clearly this is a problem for a pro.  You can rest assured I know that for sure and I'll be making a call first thing tomorrow morning.  But in the meantime, can any of you helpful folks shed some light on what the heck might have happened?  Could my wet return be clogged?  It runs below the basement floor for about 10 feet, and there are no valves in place to flush it out.  I know that it was dug up and replaced 4-6 years ago, but prior to that I think it went almost 90 years before being replaced.  Could it clog up that quickly?  I should point out that I have not yet had my annual service/maintenance, so the boiler has sat untouched since we last used it in March.

Rod

Flooded Boiler

Hi-  It sounds as though you have a flooded boiler. First of all shut off the burner so it can't start. Then shut off the fill water and drain the boiler down to the normal level in the sight glass. You want to empty the excess water out of the system so if doesn't overflow into your house.



Water can only get into the boiler from two sources:

1. .By way of the water fill /makeup water to the boiler.

    Do you have an automatic water fill?

2. If you have an internal coil that makes domestic hot water, that coil may have sprung a leak.

   Does your boiler have an internal HW coil? 

- Rod

j a_2

flooded

If I read your schematic correctly and the boiler was flooded to that point the pressure troll should have shut it down...Find out why it didn't, failed unit,clogged pigtail, or maladjusted...Secondly i don't think you take domestic hot water off of it being it was not run since last season..I would be checking the fill valves for any bypassing i e a bad washer or partially left open valve And if you do have the so called auto feeder it may as well failed    Good luck and don't panic all will be fine, its not uncommon

crash2009

Good job on the new main vents

  It's a pain getting up there in the floor joists, up and down the ladder, etc.  Maybe you just simply bumped the manual fill valve, while you were working on the vents.  I don't think you need a pro just yet.  Drain the water down to the correct level, and re-check all the fill valves.

Erik_M

THANK YOU . . .

 . . . for the helpful replies.  It never ceases to amaze me how knowledgeable and professional you all are.



Rod - I do have an automatic water fill (see photo).  Could this have malfunctioned and allowed too much water into the boiler?



Could someone walk me through the best procedure for lowering the water level?  Should I simply use the LWCO to do this?  Or, is it better to use one of the other drain valves on the boiler?  I've attached photos of the only 2 drain valves I see. 



Thanks in advance.



Erik

Rod

Flooded Boiler

Hi- You can use either the LWCO or either drain valve. I would use the drain valves as it would also allow you to drain off any sludge in that area.

As J A , who is a steam pro, mentioned it sounds as though for some reason your automatic water feeder failed. You can either rebuild or replace it or just stay with manual feed using a manual valve.



.You didn't mention whether or not  you have an HW coil in your boiler. J A makes a good point in that since the boiler has been shut off it is unlikely that you have one, however, I know several people like myself that switch over to an electric water heater in summer so I thought I had better ask. I gather you don't have an internal HW coil?

- Rod

Erik_M

That is correct . . .

 . . . I do not have an internal HW coil.



I will go ahead and lower the water level when I get home tonight.  Is there any test I can perform to determine if the automatic water feeder has failed? 

Rod

Boiler Flooding

Hi- okay since you don't have an internal HW coil then it must be something to do with the automatic water feeder as that is the only other source which can add water to the system.

There are two possibilities:

1. The automatic water feeder is malfunctioning due to leak because of a  bad seal or valve or a more remote possibility the manual bypass valve is leaking

2. The automatic water feeder is working correctly. What is happening is that due to a partially clogged wet return piping, the condensate is slow getting back to the boiler. If the boiler waterline drops due to the condensate (water) not immediately returning, the LWCO is activated which in turn activates the automatic water feeder.  This cycle keeps adding more and more water to the system until the boiler and piping are completely flooded.



To test for possibility #1 -  Shut off the burner and drain the boiler down to the normal waterline level.  With the waterline at the correct level , open the shut off valve to the water feeder. Since the power is off the water feeder can't activate. If the valve in the water feeder is bad, water will leak through the feeder and the water level in the boiler will rise.

To test for possibility #2 -  If the water feeder passes test #1 and apparently isn't bypassing (leaking) water into the boiler, the next thing would be to run the burner, make steam and watch the operation for a while. If the LWCO activates, it means that the condensate is slow in returning to the boiler which is probably due to a partially plugged return. The buried return you mentioned having is a trap for all the dirt and crud that collects in the system. I would set it up so it can be flushed out annually. (see attached drawing)   I don't have a buried return but have the same basic setup on my return line.



As J A mentioned you might also want to check your pressure control to make sure it is properly working. 

- Rod

Erik_M

Thanks Rod

How long should I wait during test #1? I imagine if it's a substantial leak I'll notice the water level begin to rise within a few minutes, but if I see no immediate change, should I leave it for an extended period (say, over night) to look for a slower leak?

Erik_M

Thanks Rod

How long should I wait during test #1? I imagine if it's a substantial leak I'll notice the water level begin to rise within a few minutes, but if I see no immediate change, should I leave it for an extended period (say, over night) to look for a slower leak?

Erik_M

Hey Rod . . .

. . . come to think of it (and I don't know why this didn't dawn on me sooner), I recall hearing the water feeder running in the middle of the heating cycle during my test run last night. I thought it was odd because I only recall it ever running at the end of each cycle in the past. If my memory is correct then this would mean that my condensate is slow getting back as you explained. I will still go ahead with the leak test first to rule out that possibility, but now that I'm reading your explanations I'm putting two and two together and leaning towards the return line being my problem.



Will update late this evening or tomorrow morning. Thank you again.

Rod

Boiler Flooding

Hi-  If a leak isn't readily apparent I'd check the water level on the hour for a couple of hours and if no change,then  leave it over night. It could be just a one time thing like a piece of dirt on the valve seat.

Due to the potential problem of automatic water feeder flooding, a lot of people chose to manually add water to their boilers.

If you are going to use an automatic water feeder I would go with one like the Hydrolevel VXT-120

http://www.hydrolevel.com/new/index.php?option=com_content&task=view&id=50&Itemid=

which have a counter so that you can see how much water has been added and other built in programs that prevent too much water being added.  Even then this type of automatic water feeder can still fail and cause flooding.

- Rod

Rod

Flooded Boiler

Hi- An automatic water feeder, in reality, should hardly ever run. Unless the steam system has a lot of steam leaks due to things like leaking radiator inlet valves or non closing radiator vents, the amount of water lost from the system is very small. ( I read somewhere that Burnham states their IN8 boiler (a big boiler!) should use no more than 3 /10 of a gallon per month)  Usually most of the water added is just to replace the water lost during the weekly blow down / testing of the LWCO. 

If your boiler's automatic water feeder is operating regularly especially at the end of the cycle makes it sound like you have a partially blocked return.  You on the right track doing the leak test first and then addressing  the return.

- Rod

crash2009

Getting back to draining the boiler

  As mentioned previously, use either of those drains.  I prefer to use the lowest of the two.  If they havn't been open in awhile, they might be plugged shut, and nothing comes out.  Work a coat hanger up inside the hole to get it started draining.  Sometimes the opposite happens, and it won't shut off, it just continues to drain. 

Stop by the hardware store on the way home from work tonight and get a couple of these brass (not plastic) garden hose caps.  They might come in handy if you can't get the drain closed again.  And even if you don't need them today, they won't hurt anything to leave them installed on the drain for the future.

Erik_M

UPDATE

I used the lowest drain valve to lower the water level back to normal.  I marked the level on the sight glass and so far no change after 1 hour.  Will check again in the morning. 



CRASH - THANK YOU for your advice about the end caps.  I picked some up this afternoon and sure enough I needed one to stop a slow drip from the drain valve I used.



Assuming there is no change in the water level by morning and my water feeder is not leaking, my next step is to flush the return.  Upon closer inspection, it does appear that there is a clean out at one end (the end closest to the boiler).  At the other end (where the two vertical return lines come together before going beneath the basement floor), there are some fittings I am not familiar with.  I'm wondering if any of them are fittings I can disconnect for the purpose of flushing the floor section.  I've attached photos of both ends.



If I can indeed use the clean out below the floor and uncouple a fitting on the other end, how do I go about flushing the return?  Is it as simple as running a garden hose from the end opposite the clean out?



Thank you all again for your generosity and expertise.



Erik

crash2009

Not quite sure

what to say about that one.  Could turn into a big can of worms.

Rod

Wet Return Flush Fittings

If you're going to flush the wet return you need to have a method of isolating the Wet Return from the rest of the system.  This means you need a shut off valves on the return pipes going into the Wet Return and a shut off valve on the pipe that goes from the Wet Return to the Hartford Loop.   These valves don't necessarily have to go down close to the floor. After seeing the pictures of your fittings it might be easier install the valves near the top of the drip. I drew up a drawing to show this which I've attached. You can place the valves any where along the pipes that are marked in red.

On the drips you can place a plugged tee below the valve where you can then attach a garden hose temporarily to flush out the Wet Return. (See Flush Fittings in the drawing)

On the "outlet end" of the Wet Return near the boiler you want to use a full flow ball valve with fittings to a male hose fitting that you can attach a second garden hose that leads to a drain.

Actually you might be able to just use a drain cock (like the drain on the boiler) here. I used a full flow ball valve on my wet return so I could run a "snake" through it if necessary. In your case you probably can't use a snake due to the underground portion of the return.



Running city pressurized (@70 PSI) water through the wet return for a while should clean out most of the "gunk".  If that doesn't work, you may just have to have the Wet Return replaced.  Even if you needed to replace the Wet Return, the valves and tees would be needed on the new one.  I'm a great believer in copper Wet Returns. Since I replaced mine with copper, the occasional flush makes the inside look like new. 

You may want to get a pro to put in the valves and tees for you unless you have the tools and experience to do the job. Once setup the flushing is pretty easy and you can do it yourself.  Have towels, buckets, mops etc available to pick up any spills.

- Rod

Erik_M

UPDATE #2

I checked the water level in the sight glass before going to bed last night and it had actually risen about 1/8".  This morning it had risen another 1/8" overnight.  So it would appear that the valve in my automatic water feeder does in fact have a slow leak, correct?



With the slow leak identified, I fired up the boiler this morning to let it run through a cycle and watch what happens.  Still had suspicions about a partially clogged return.  Unlike my initial test run (when the boiler was apparently flooded), the system ran flawlessly.  Most importantly, the water level never dropped, the LWCO never activated, and the water feeder never added water.  So I think I can safely say that I do not have a clogged return at this point.  Do you guys agree?



I'm thinking that when I ran the boiler for the first time a couple days ago, the boiler must have already been flooded (my fault for not checking the water level first) by the slow leak in the AWF.  Even though the leak is slow, it had plenty of time to flood the boiler while it sat unused during the summer.



Based on other other threads I have read it sounds like I have 3 options now:



1)  Replace the automatic water feeder.  Preferably with one like the Hydrolevel VXT-120 that Rod suggested.



2)  Disassemble my existing water feeder and attempt to replace the valve.



3)  Bypass the automatic water feeder and simply use the manual fill valve; paying close attention to the water level after each weekly flush.



Because we plan to replace our oil fired steam boiler with a gas fired steam boiler next year, I'm leaning towards the manual fill valve option.  Does anyone advise against this?  I understand that by not using an automatic water feeder I risk no heat if I'm ever gone for an extended period and my water level drops and activates the LWCO.  Are there any other risks or reasons not to manually fill and monitor my water level?

 

nicholas bonham-carter

Auto feed-the work of the devil

The vices of the auto feed outweigh the virtues. In the meantime, can you valve off the water supply to the auto feed? Watching the operation of the boiler with no extra water coming in will show you if you have some water loss, or slow return somewhere. If there is any oil in the water, the waterline will be very unsteady, and can move enough to activate an auto feed, so it is best for it to be mostly off.



Next job: restoring adequate venting on the mains to get the air out of the pipes, and steam chest, so the steam will start up towards the radiators simultaneously.--NBC

Rod

Go Manual

As it appears you do have a slow leak in your AWF, I'd just add water to your boiler manually. A lot of people don't use AWFs due to the potential danger of flooding.

   The Wet Return is probably okay, just keep an eye on it when the weather is very cold and the heat cycles are very long. If there is a problem with a slow return the LWCO will activate during the long cycles. When you get you boiler replaced I'd think about eliminating the buried return if possible and would definitely add the valves and fittings to properly flush it.

 - Rod

crash2009

I disabled

 my automatic water feeder also. 

4Barrel

be careful with hydrolevel autofeeder

i loved my VXT auto feeder. at first.

then i discovered it was leaking (only a couple years old) - albeit slowly... but i ended up with a flooded boiler. so this thread seemed very familiar.

it took some time, but hydro-level honored their warranty, and i replaced it... but i agree with others here - an auto feeder can be a false sense of security...

not saying you'll have that issue if you go with a VXT, but it is another link in the chain that can break. just FYI.

Erik_M

Manual it is then.

Thank you all for helping me troubleshoot this.



Rod - Thank you especially for your timely and detailed responses complete with drawings, etc.  You helped me immensely back in March by calculating proper main vent sizes for me and suggesting a method to remove a steam pipe fitting.  Your help has proven invaluable once again.  THANK YOU!  When I do have our boiler replaced next year I will offer your schematic for wet return flush fittings to the installer.



A grateful fan of this community,



Erik



 

Rod

Hi Erik-  Glad to help out!  The credit really should go to the pros who come on the Wall and generously share their time and knowledge with us.   All I'm doing is passing on what I've learned from them and from Dan's great steambooks.

 When it comes time to replace your boiler be sure to do some research as there are some very interesting developments coming out.

 http://www.heatinghelp.com/forum-thread/142452/Midco-Radial-Burner

- Rod

Erik_M

after thought

Since I'll be manually filling, should I remove the power supply to my automatic water feeder?

crash2009

Disconnect the wires

  I never even thought about that when I disabled mine.  All I did was shut off the hand valve and the bypass valve.  But now that you brought it up, you got me wondering if the feeder is wired in series with the safeties.  My guess is that is is and you should leave the wires alone.  If you break the circuit, the boiler won't start. 

malex

Also

Make sure you flush out the LWCO if it's a float type. First time I turned on my boiler it was stuck because off sludge so the auto feeder came on. I did not notice it until water was spewing out of a vent on 2nd floor...