Weil-Mclain LGB boilers

Krum

Have two boilers that are sooting on one side and working well on the other side.
what could be the reason?
C/A is sized properly for both boilers - one operates at any given time only.
any advice

EBEBRATT-Ed

Need to combustion test. Also make sure burners are properly seated, not crooked etc. Check gas pressure etc. Make sure flue is unobstructed and properly sized. Check orifice sizes.

Make sure boiler flue passages and smoke hood are clear.

EdTheHeaterMan

Is the heat exchanger blocked on the side that is sooting? That needs to be thoroughly cleaned with a brush from the top and the bottom. The spaces between the sections can have nothing blocking the airway that the flue gas travels thru the heat exchanger. Getting someone to do that is often difficult because you need the vacuum cleaner and brushes that are usually used on an oil burner. Not every plumber or HVAC guy that works primarily on gas heat has those tools.

Krum

thank you for the help. just to clarify: the boiler is brand new, and the flue is new as well. All new installation. A combustion test has been conducted and didn't help at all. we have installed a draft inducer but didn't solve the problem. it is quite an odd situation.
thanks

JUGHNE

Could it be not enough gas pressure to completely fill the manifold all the way across?

captainco

That boiler has its own draft inducer why would another one be added. If the combustion test did

Krum

captainco said:

That boiler has its own draft inducer why would another one be added. If the combustion test did

the LGB boiler does not have inducer.

EdTheHeaterMan

Just throwing this out there for no reason.

Soot is a result of incomplete combustion. That usually means there is too much fuel or not enough air. LGB uses atmospheric burners. What if the orifice size on the burners was incorrect? This is on page 9 of the I/O manual

captainco

Pushed the wrong button. The combustion and draft test should have narrowed the problem down unless the person doing the test doesn't know how to test and diagnose correctly. High CO? Rising CO? Low O2? Falling O2? Flue draft above -.02" or below?

Krum

EdTheHeaterMan said:

Just throwing this out there for no reason.

Soot is a result of incomplete combustion. That usually means there is too much fuel or not enough air. LGB uses atmospheric burners. What if the orifice size on the burners was incorrect? This is on page 9 of the I/O manual

This will be the next step.
thank you for the help.

mattmia2

What about your return water temp, is the sooting section where the water returns and you aren't keeping it hot enough?

mattmia2

Is this hot water or steam?

Krum

Steam system.

mattmia2

Then it isn't return water temp unless maybe if it is running a hot water loop or an indirect. while you have the jacket off to clean it, take a good look for some sort of defect in the casting or debris that got left inside during manufacturing.

Krum

the contractor installed it properly. all new installation.
strange strange sooting case.

JimP

If you’re still at a loss double check the chimney flue. Maybe something caused it to become partially obstructed. If it’s a new flue up the chimney maybe you could go to the top and look down?

Krum

JimP said:

If you’re still at a loss double check the chimney flue. Maybe something caused it to become partially obstructed. If it’s a new flue up the chimney maybe you could go to the top and look down?

new chimney liner without any obstructions even has an inducer on the top.

pecmsg

Combustion analysis by Qualified NCI trained  personal. 

EdTheHeaterMan

Krum said:

EdTheHeaterMan said:

Just throwing this out there for no reason.

Soot is a result of incomplete combustion. That usually means there is too much fuel or not enough air. LGB uses atmospheric burners. What if the orifice size on the burners was incorrect?

This will be the next step.
thank you for the help.

Another thought about soot, incomplete combustion, and WILD A55 GUESS theories: Are there any leaking refrigerant containers stored in the boiler room that might be depleting the oxygen on that side of the boiler room? Is this a CO2 fire extinguisher refilling station? Where is the combustion air coming from?

I know… that is way out there! But I illustrated it anyway.

Matt_67

Is the burner with the pilot assembly in the correct position?

Krum

EdTheHeaterMan said:

Krum said:

EdTheHeaterMan said:

Just throwing this out there for no reason.

Soot is a result of incomplete combustion. That usually means there is too much fuel or not enough air. LGB uses atmospheric burners. What if the orifice size on the burners was incorrect?

This will be the next step.
thank you for the help.

Another thought about soot, incomplete combustion, and WILD A55 GUESS theories: Are there any leaking refrigerant containers stored in the boiler room that might be depleting the oxygen on that side of the boiler room? Is this a CO2 fire extinguisher refilling station? Where is the combustion air coming from?

I know… that is way out there! But I illustrated it anyway.

pure mechanical room heating small building - 4 floors above.
No refrigeration or any possible leaks.
I think I know what is the problem. If I am right will share the results here.
thanks to all of you guys for the help.
cheers