Troubleshooting steam boiler water loss

da13ear

Hey guys, Happy New Year!

I just replaced most of my house's old rad vents with new vent rite 1s. Rads are heating up slow and hot as you would want (I've used my temp gun and see temps of 220. Need to check the last upper and lower section to confirm).

Here's the thing - I don't think any of the rads vents ever close. Why?
A. I don't hear them clink like the old ones (I assume I should hear a metallic click when they close like the others?)
B. I can hear and feel steam gently coming out of them (tried the mirror test to confirm its steam).
C. Boiler runs low on water over the course of 24 hours. ( Checked around rads for leaks and haven't found anything major yet. returns are copper but havent checked them for leaks. Also no white smoke out chimney indicating a cracked boiler)

So the heat is fine but the water refill is clearly bad. Process of elimination leads me to think my vents are not closing and the steam is simply slowly escaping all my rads. Thoughts?

Thanks as always,

Chris

PS two things I forgot to mention:
1. My boiler guy down fired the boiler by 10% to alleviate some high pressure before I started noticing this. (Doesn't seem to correlate but I wanted full transparency)
2. I am testing this during normal "maintaining temps" operation... Haven't tested during a setback.

PPS added pics

dabrakeman

You have had a few discussions about vents and adding a low pressure gage but otherwise we don't know much of anything about your system (type, pictures of the near boiler area, pictures of representative radiators). If you are seeing steam at a radiator vent let alone escaping from a radiator vent while only maintaining constant stat temperature it seems a bit odd unless your system is very unbalanced, you have an oversized boiler or it is 10 below or so in your area. I assume your radiator is hot all the way across when you are witnessing the steam release? If not are you sure it is not still just venting air? Anyway if it really is steam escaping your radiator vents then the vent is shot and the real question is how did it get that way, particularly if numerous vents. You mentioned you had a high pressure issue prior to the downfire...

SteamingatMohawk

There are numerous comments in HH on high pressure causing vents to leak. You mention high pressure being the reason to downfire your boiler. What is the actual operating pressure range of your system?

da13ear

Hey guys, thanks for the feedback. I've attached pics as requested to the OP.

@dabrakeman I need to do a proper EDR to check system sizing. I checked the rad temps across while they are running for 20min....they are 210+ on tops and bottoms across the entire rads. I tested the venting by putting a mirror up to the air valve. It left condensate. One more note - it seems like they close eventually but it takes a long time and steam seems to come out.

@SteamingatMohawk Operating pressure is difficult to tell since I don't have the low PSI gauge in yet. I have the pressuretrol set to 0.5 with a 1.25 offset, and after a setback, it would run for a good 35+min before it cuts the flame. During normal firing to maintain temps, the pressuretrol never kicks in.

Chris

SteamingatMohawk

If the pressuretrol operates properly, my uneducated opinion is the pressure is not high enough to cause a functional vent to leak, certainly not a new one, unless it is defective.

SteamingatMohawk

Hopefully, since the vents are new you didn't use excess sealant ( pipe dope or tape) potentially getting into the internals of the valves.

One no cost, simple thing to try, which may or may not work is to set the valve to 8 (maximum) and blow air backwards into the vent opening with the valve still installed (not preferred). If there is anything inside the valve, it may clear the opening.

You can try it in place to see if there is a difference, and how long it lasts. If the leak comes back, try again with the valve removed. If something comes out it may be positive proof of the problem. Cross you fingers hoping you solved the problem.

da13ear

Thanks @SteamingatMohawk! When the boiler was firing and the valves venting, I turned it up to 8. It vented super fast until i heard the clink, so i know it's working eventually. I still feel like the Vent-rite air valves are venting some steam (or at least really humid air) for awhile before they close.

Dave in QCA

I really suspect that when you are doing the mirror test, you are detected humid warm air coming out of the vent. That is not the same thing as steam. You are observing that they do close when steam eventually arrives. I might also ask if you put your hand on the vent when you were doing the mirror test. If there is steam at the vent, you would not be able to keep your hand on the vent.

da13ear

@Dave in QCA definitely don't need to pull my hand away at all. Can be hot, but not 160+ degrees. Appreciate the feedback.

On a separate note, I just fixed a drip in a elbow valve on one of my larger rads. Will see tomorrow how much that helps the water loss. After that, most likely I need to open up some drywall to look at the returns.

Chris

da13ear

Hey guys, wanted to update everyone on my boiler which is losing up to 7 gallons of water a day during super cold days.

1. Can confirm the new ventrite rad vents are closing when steam hits.

2. Checked the returns and don't see a leak (there is a part behind a wall, but I figure 7 gallons would cause a mess)
3. Don't see white smoke out of the chimney when the boiler is steaming.
4. Found one leaky elbow that I fixed with some pipe dope.

Any ideas on next steps? 

Reading through the forums, I've seen some ideas:
A.open the boiler lid and remove the flue to see if there is rust.
B. Fill the boiler above the steam line to see if water leaks.

C. Cut open the wall and finish inspecting the long copper return.
D. Calculate EDR to make sure it's not pressure related.

Did I miss anything?

I am trying to gauge how much to mess with things now vs warmer season.  I assume you pros would suggest I ride it out until the winter is behind us.

Thanks,

Chris

ratio

Pick up an IR camera of some type. (I have a Flir One Pro that plugs in to my cell phone.) They'll help you find the leak, plus they're a lot of fun. Note: they're best at ΔT measurements, not absolute temperature (without spending some effort on calibration), but a patch of masking tape on the surface is supposed to give good results.

JUGHNE

Overfilling up to where the header feels cold from fresh water....buy no higher....will perhaps tell you pretty fast where your leak could be.
But if, during this test, you have water dripping onto your burners, stop filling and drain down right away.

Wet burners/pilot light need to dry out before refiring.

da13ear

@JUGHNE so this is something I most likely should save for March once it starts warming you think.

ethicalpaul

I wouldn't say that. If I were losing 7 gallons a day I couldn't sleep until I found the cause

SteamingatMohawk

A day is 24 x 60 = 1440 minutes.
7 gallons is 7 x 128 = 896 ounces

The usage is 896/1440 = .62 ounces per minute.

Can you determine how much the water level goes down during the time the boiler is running compared to the time between heating cycles? It may tell you something.

KC_Jones

7 gallons a day, you are "aging" that boiler with fresh water equivalent to 1 year, per day.

I agree with @ethicalpaul I'd be on a mission until I found that water loss.

Assuming you would find a mess with a leak behind a wall isn't really correct.  These old houses have cracks and crevices all over, I could easily see my house "eating" 7 gallons of water without my knowledge, that is until I found it.

da13ear

Thanks for the feedback guys! So next steps:
1. Tear open drywall to check return.
2. Flood boiler to top to see if I have a leak.

One question - if i don't have steam (white smoke) coming out if my chimney, does that mean its definitely not a leak in the boiler?

da13ear

SteamingatMohawk said:

A day is 24 x 60 = 1440 minutes.
7 gallons is 7 x 128 = 896 ounces

The usage is 896/1440 = .62 ounces per minute.

Can you determine how much the water level goes down during the time the boiler is running compared to the time between heating cycles? It may tell you something.

Water definitely goes down during steam, not when off.

JUGHNE

I would do the boiler overfill flood test.
Just be cautious of water on the burners.
Let sit an hour at least.

If good then look in other places.

Any pipes under the floor?

da13ear

@JUGHNE no pipes in floor. Copper wet returns.

da13ear

Hey guys, Opened up the wall and checked the entire wet return.  No leak.   Based on your feedback, the last thing is to shut the boiler down and fill up to the top to see if there are any leaks coming at the high water line.
A few more questions:
1. Saw intermittent white smoke from chimney today for first time.   I've looked a bunch of times before and never saw it. Does white smoke ONLY happen if there is a a hole in the boiler, or can it be that today is so cold and humid at the same time? (Snowing in NY)

2. System still pressurizes to 1.5PSI during firing. Would that happen if there was a hole? (I guess it depends on the hole size)

Thanks guys.  This time of you year you're heroes!  Hope you're all keeping warm.

Chris

Jamie Hall

If it's just occasional wisps of white smoke in weather like this, I'd not worry much about it. A nice plume? That's a problem.

7 gallons a day is a lot -- but spread over 24 hours, you could be looking at several small leaks (bad valve packing, leaking threaded joint, etc.) instead of flood. Keep looking.

da13ear

Thanks Jamie.  And BTW thanks for all the feedback you are always willing to give.

Never saw the chimney like that before, but it was definitely a plume for a few min and then gone.   I assume it is when the boiler is firing. 

 I will fire it tomorrow again and see if the plume comes back.  I will keep digging inside too. 

 I read someone changed their main vents and alleviated a leak problem, so I will try that too.

JUGHNE

The quickest and least disruptive thing you can do is to "flood" the boiler.
That may or may not give you a definitive answer, that perhaps you do not want.

SteamingatMohawk

You may not see water stains, but there may be buildup of corrosion products at leakage sites. Copper corrosion is the light bluish color, rust for iron in pipes, fittings and steel or black iron valves.

da13ear

@JUGHNE you know.  Ive never done it before so I'm just agonizing over that.  It's still top of my list but I'll feel more comfortable doing it when the temps are a bit higher.   I've also reached out to a pro from her to come in for a diagnostic.

Thanks bro.

bkc

Hi all,

How much water loss is acceptable per day, month or year?

I am maintaining a 22 HP boiler on a 2-pipe system that I think is losing too much water. But I don't know how much is reasonable.

Adding only what I intentionally drain each week would be 0 loss, but is that realistic? What's acceptable, what's typical?


@KC_Jones said 7 gallons is a year's worth of water, that's got me worried because I'm sure our system is way over that.

Jamie Hall

Well, at last count I get 22 hp equal to about 55,000 BTUh -- not a big boiler. With a boiler that size, I'd say anything much over a gallon a month -- exclusive of any blowdowns -- is cause for concern, and a gallon per week I'd get really nervous.

dopey27177

IF I am reading you correctly you have a 220 degree temp at the radiators. Steam at 220 is equal to 3 psig. Reading off the radiator you need to add another 10 degrees so that would put the steam pressure at about 4.5 to 5 psig.

Lets say for the purpose of my suggestion the vents on the radiators are good.

I saw the old radiator valves, you can lose steam or water vapors through the packing glands,
Check to see if the handles are loose, if they are you need to repack the radiator valves.
If the packing glands have a slight leak you will not see water vapors or steam.

A comment was made that warm water vapor leaving the vents is ok, that in this sense is not true. If it is water vapor that's boiler water.

The pressure in your boiler should not exceed 1.5 psig. That is about 215 degrees which means the temperature at the radiator should be about 205f.

You need to get a low pressure pressure gauge so you can set up the operating steam pressure.


Did you check to see if there is leakage from the boiler safety valve?

jake

da13ear

You got it @dopey27177 . The one caveat is that the rads have those wooden decorative box covers. Not sure if that would increase the heat at the rads when at full pump.

The ancient handles are definitely loose. Repacking is preferred over replacing right? With graphite string, ptfe, or pipe dope?

Lastly, I feel like this all happened around the same time as I replace the rad air vents. I replaced them all because some knuckleheads came in and loaded a ton of 8way causing insane surging, hammering and pressure buildup. That caused many of the old watts variable air vents to leak. The new ventrite 1s dont seem to make that familiar clink when closing so i am not sure they are closing all the time. I tested this by opening one wide during a firing event, and it close for sure with a clink.

I can of course also swap all the air vents to a different brand as a test as well.

Chris