Steam boiler water loss - Should I bother chasing it? Detailed info and pictures included.

pcolburn2

Hi everybody.

Some relevant information.
1. Weil Mclain EGH 125 installed December 2020. I think it holds 21 gallons of water but I may be mistaken.
2 All original mains and wet returns from 1912 other than 20 feet of wet returns replaced in 2021.
3. 30 radiators (29 are behind locked tenant doors), 30 Hoffman 1A radiator vents
4. 4 Hoffman 75 vents in basement on the mains
5. System does not lose a drop outside of heating season.
6. Probe type LWCO is on the other side of the boiler and is around and inch or so below the sight glass.

This picture was taken on January 9, 2023. Water level is at marked black line. Feed counter at zero.


This picture was taken today, Ferbruary 6, 2023. This is inclusive of our frigid weather this past weekend in the Northeast. Feed counter at 2. We have the dipswitch set to feed 2 gallons at a time. Water line about 1/5 of the sight glass.Steam is up and in the radiators at this moment in time but burner is not on.


Is this evaporation or is this enough water loss to start going unit by unit and checking vents and shuotff valves?
I'm struggling to understand how much water the column of the sight glass represents in water loss in the heat exchanger. I know the feed counter is a timer and not a water measurement device.

Thanks for any assistance you can provide.

ethicalpaul

Yes it's worth it. The introduction of fresh water will lessen the lifetime of your boiler. You are apparently leaking steam from some places.

To see what the gauge glass represents, fill it to the top, then drain 1 gallon at a time and mark the level on the glass. Repeat until the glass is empty. Then you'll have a graduated glass.

Ironman

You really need to get inside each unit and look for leaking radiator valves, vents malfunctioning or removed. etc.

EBEBRATT-Ed

Especially with a 3-year-old boiler. Make up water will cause a slow death. Could be a bunch of small leaks. If steam is leaking, you may see no water. Use a mirror it will fog up if steam hits it. Chech all vents and valves.

Wet returns are usually the first place to check. I realize you said it only leaks when running but a wet return could have rotted through. If it truly only leaks when running it probably is a steam leak.

pcolburn2

Thanks for the comments everybody. Does the fact that it is a commercial boiler with more vents than a normal residence, does it drive any different thinking in terms of allowances for evaporation?

Jamie Hall

Agreed. You need to do some looking around. The most likely problems are in the units, with very slight leaks on the radiator valves (the packings do leak over time -- but that's easily fixed) or vents which are tired and don't quite close. Both of these problems are aggravated by excess pressure -- anything over 2 psi is too much.

The other place where there can be leaks is in the steam lines themselves, almost always at threaded connections where water may pool, even just a little bit. These can be really hard to find, but inspect all the joints you can see for signes of corrosion or possibly dampness.

You are not looking for a puddle. If it's a leaky valve packing or vent, the odds are you won't see it at all -- the steam just evaporates. Even a leaky connection may be hard to see. Remember that even a little tiny drip -- one drop every 20 seconds -- is around a gallon a day!

Long Beach Ed

I have similar buildings. When I do major work like a boiler replacement, I check the system and fix leaks like these.

During a summer week, I replace all the radiator vents with 1/8" plugs, plug the main vents and pressurize the system with 15 lbs of air. Sometimes this take a helper. Then I go from apartment to apartment tightening and repairing radiator valve packing and tightening leaking radiator unions. ...and usually the sight glass nuts.

Sometimes I find a leaking saddle tee or something odd leaking too. Also a good time to check the vent valves I've removed by inverting them and blowing through them, making sure they seat.

A day's work and the system's tight for the first time in eighty years. It usually remains that way too. You can also check the closing of radiator vents during heating season.

Probably not necessary but follow the boiler manufacturer's guidance on amount of permissible make-up water. Just good practice to have a leak-free system and good for the boiler.