Excessive Make-Up Water

JAdams

Weil McLane CGI LP Gas Boiler. Closed loop system. 30% Glycol, 70% Water. Mixture is pumped into a pressurized (24 PSI) 20 Gal capacity tank. Maximum accepted volume is 11 gal. In one month time, all 11 gals were fed into the heating system. There is no visual signs of leaks. All zones and piping have been pressure tested @ 80 psi for a 24 hour period with no pressure loss. The boiler was not pressure tested. The vent pipe was removed and visually inspected for any residue. Any residue appeared normal, yet it's hard to tell. The jacket was partially removed from the boiler to inspect the cast iron for possible leaks (see attached photo's). It is my assumption that one of the O-Rings between the sections went bad and fluid is seeping on the inside of the heat exchanger and is being burnt off. There is no signs of fluid in the burner area, yet the fluid is going some where. Any input will be greatly appreciated. The attached photo's may tell a lot.

Jamie Hall

It wouldn't be the first time one of the o-rings in a Weil-McClain gave trouble -- and not necessarily because it went bad. They can get twisted during installation (ask me how I know) and then they may leak. Can you pressure test the boiler?

aircooled81

Air worked its way out the vents, water made up the void?
The boiler leak sounds more likely?
Expansion tank lost charge, water filled the void?
Doesnt glycol do damage to some o-rings?
Pressure releif popping off and discharging water?
If the flue isnt corroded like the heat exchanger, thats not likely condensate.
Can you run the boiler, get it up to high temp, valve it off and see if the pressure falls rapidly after the burner shuts off? Put a guage with very small incraments to see pressure change better.

Solid_Fuel_Man

if the boiler is heated then valved out (isolated) watch where the expansion tank is, as the water cooling in the boiler will contract and the pressure gauge's boarden tube will be the only "expansion vessel" there is. A good boiler will show a fast pressure drop from water contraction.

SFM

JAdams

aircooled81 said:

Air worked its way out the vents, water made up the void?
The boiler leak sounds more likely?
Expansion tank lost charge, water filled the void?
Doesnt glycol do damage to some o-rings?
Pressure releif popping off and discharging water?
If the flue isnt corroded like the heat exchanger, thats not likely condensate.
Can you run the boiler, get it up to high temp, valve it off and see if the pressure falls rapidly after the burner shuts off? Put a guage with very small incraments to see pressure change better.

Thermal Expansion tank is @ 15 psi, not full of water.
PRV is not leaking.
SS Vent pipe, no corrosion visible.
I can isolate the boiler from the system. Isolation Valve is on the Boiler side of the Expansion Tank, however, I can isolate each zone as well so that the Expansion Tank will be part of the test.

Thank you for your input.

JAdams

@Solid_Fuel_Man

Thank you

JAdams

I sent these pictures to Weil McLain. The Tech guy I talked to there seems to think the rust marks on the exterior of the battery are from the unit being stored outdoor at the factory....lol Although he may be partially correct, I think he missed, or overlooked the darker rusty marks, which seem to be more recent.

ChrisJ

I don't see any rust on the block that would suggest leak in my opinion.

You won't know anything until you pressure test the block with ti isolated. Air will show a leak easier and faster than testing with water.

Fred

If all the zones and piping pressure tested ok, the boiler is the likely culprit. The only thing about the pictures that is suspect, at least to me, is the rust trails, which suggests a possible leak up high or on top of the boiler block. If that rust was from the boiler sitting outside, I would have expected a more even coating of rust over the entire block and some smearing/smudging from handling the block during installation.

ChrisJ

Fred said:

If all the zones and piping pressure tested ok, the boiler is the likely culprit. The only thing about the pictures that is suspect, at least to me, is the rust trails, which suggests a possible leak up high or on top of the boiler block. If that rust was from the boiler sitting outside, I would have expected a more even coating of rust over the entire block.

Cold block sweats when the burner fires, probably even under the insulation.

Could also get dew on it when sitting out side which would run down like that.

JAdams

ChrisJ said:

Fred said:

If all the zones and piping pressure tested ok, the boiler is the likely culprit. The only thing about the pictures that is suspect, at least to me, is the rust trails, which suggests a possible leak up high or on top of the boiler block. If that rust was from the boiler sitting outside, I would have expected a more even coating of rust over the entire block.

Cold block sweats when the burner fires, probably even under the insulation.

Could also get dew on it when sitting out side which would run down like that.

I don't believe this block sweats. The rusty run marks on the back of the boiler are different color than those on the front side. The lighter color run marks may be older. The darker color run marks (on front of cast iron only) appear more recent, maybe I'm wrong. There are some lighter colored run marks on the front side as well. The darker colored marks appear to concentrated in one specific area, more towards the output of the block. Also, it appears wet under the tie rod on the front side of the block, but it's hard to tell.

I'll just have to drain all the liquid and pressure test with air to be certain.

JAdams

@Fred..... thank you

aircooled81

I have always been partial to a hydrostatic test. Air test on a vessel with no releif is fairly dangerous. With a releif, you still stand the potential for a crack or weak spot to explode, rather than drip.
Remember water does not compress, far less kinetic energy than air. Air is compressed, and when given the option to escape it does this fairly quickly.
If you can just use city water to force feed the boiler you are a bit safer, and if you need more pressure you use the aircompressor to boost it when full.
My earlier theroy involved heating the boiler, than quickly valving it off, as the expansion may show the leak that a cold test doesn't.
Not sure if having the expansion tank in that test is helpful, as id like to see the pressure drop as rapid as possible, rather than trickled in by the expansion tank.

ChrisJ

aircooled81 said:

I have always been partial to a hydrostatic test. Air test on a vessel with no releif is fairly dangerous. With a releif, you still stand the potential for a crack or weak spot to explode, rather than drip.
Remember water does not compress, far less kinetic energy than air. Air is compressed, and when given the option to escape it does this fairly quickly.
If you can just use city water to force feed the boiler you are a bit safer, and if you need more pressure you use the aircompressor to boost it when full.
My earlier theroy involved heating the boiler, than quickly valving it off, as the expansion may show the leak that a cold test doesn't.
Not sure if having the expansion tank in that test is helpful, as id like to see the pressure drop as rapid as possible, rather than trickled in by the expansion tank.

If I was doing an air test on a boiler, I'd use a hand tire pump and pump it up to 15-25 PSI.

No need for a relief valve, and I'd assume the stock relief valve would be installed anyway.

I personally see no danger at these pressures especially using a hand pump. I wouldn't go any higher though for the reasons you stated.

JAdams

@chrisJ & @aircooled81 The boiler was tested @ 50 psi direct from the factory (tag on the side of the housing) with water. Testing the unit with air shouldn't matter as long as I do not exceed the 50 psi rating. I looked at the parts breakdown drawing of the boiler. There is an O-ring at the top of the two sections where it looks like it's leaking. Being water is heavier than air, I believe air is the way to get a more positive test. However, I will try your suggested test first. Thank you.

Ironically, this happens to be the same system in an earlier post in regards to a WM Gold Plus back in 2015

ChrisJ

Air leaks far easier than water, so it makes it a tougher test IMO.

@Hatterasguy I just felt a hand pump is slower, and much harder to exceed the pressure rating with.

That's all.

Some of us, aren't afraid of manual labor.

ChrisJ

Hatterasguy said:

ChrisJ said:

Air leaks far easier than water, so it makes it a tougher test IMO.

@Hatterasguy I just felt a hand pump is slower, and much harder to exceed the pressure rating with.

That's all.

Some of us, aren't afraid of manual labor.

Many of those compressors have adjustable outlet pressure and the flow diminishes as the target pressure is neared.

Some of us would rather use our heads................

Yeah...
You always have been full of a lot of wind..

JAdams

@ChriJ @Hatterguy @aircooled81 @Solid_Fuel_Man @Fred @Jamie Hall

OK, so this is what I did to test the boiler. I forced a call for heat, the unit did it's thing and fired. When the temp reached 180, the aquastat did it's job. I turned the power off and isolated the boiler from the rest of the system, expansion tank included. The pressure and temperature in the boiler started climbing quite rapidly. I didn't want the 30# relief valve to open so I had to open the ball valve and let the expansion tank do it's job. There were no signs of leaks on the block. The pressure dropped back to 15 psi. Then I got this bright idea of doing the same test, this time isolating the expansion tank and all but one heating zone (the basement). I wanted to see if the pressure would rise as it did in the first test. I was thinking the same thing would happen, but it didn't, the pressure rose to 22 psi and stayed there for a few minutes, then started to decline. So, I said to myself "****" and went and started to check all the baseboard in the basement, again. As I was crawling along the carpet, one particular section felt a little damp, but it was hard to tell. As I tried to determine whether it was damp or not, then I saw it, I saw a drip come from the seam of the tongue and groove cedar board. After cutting the wall open, it was clear that there was a leak. The carpenter put a nail right smack in the center of the 3/4 M tubing when he put the cedar on, 5 yrs ago. I can't figure out why it took so long to leak, I can only assume expansion & contraction and the nail finally rotting.

I thank you all for your input and advice on this.