stinkey boiler water and air production

Steve Whitbeck

30 year old boiler system in a church, copper fin tube, 15 year old Dunkirk boiler.

2 inch common return, boiler is piped primary/secondary, 2 inch in line seporator, 2 inch header with 4 zones ( pumps with check valves )

The problem is that the boiler is producing air.

As soon as the boiler temperature gets above 170* I get air bubbles coming out of the boiler supply, The boiler water really stinks and is dark in color.

The air is pocketing in one of the pumps and causing it to stop pumping ( UP 15-58 )

This is creating enough air to fill the pump inside of 15 minutes.

Is their algie or bacteria growing in the system that generates air above 170*???

I am thinking on injecting bleach into the system and letting it circulate and then flushing the system.

What are your thoughts.

Steve Whitbeck

stinkey boiler water and air production

Forgot to say the system is not taking on water.

Unknown

boiler is producing air.

Boilers do NOT produce air,,, but as the water is heated within it will expand any air bubbles picked-up from other areas such as automatic air-vents or new feed water admitted to the system(if there is a leak somewhere). :-)

Steve Whitbeck

stinkey boiler water and air production

OK - the boiler doesn't produce the air BUT the air is produced inside the boiler due to heating of the water. ( I am a boiler installer for the last 34 years )

The air bubbles don't expand due to heating. They come from the water ( there are extra oxygen atoms mixed in with the water and heating the water seporates them from the water and creates the bubbles.

I specialize in Hydronics.

Unknown

OK!!!!

Your point being????????

I`ve been a boiler man for 35 yrs,,,, we NEVER stop learning do we? :-)



BTW- Of course air expands from heating within the boiler,,,, how do you explain steam?

Jamie Hall

I am led to wonder...

if there is a leaking seal on one of the pumps.  If the seal is on the intake (low pressure) side, I've seen them suck air into the system, even when the system pressure seems plenty high.  Could that be?  It probably wouldn't show when the pump was stopped.



That water sounds nasty -- but you're probably a much better hot water boiler guy than I am (steam's my thing) so I wouldn't know what to do with it, besides turning up my nose...

Steve Whitbeck

stinkey boiler water and air production

Pumps are all wet rotor ( NO way for air to get in.)

The system has a compression tank that is not water bound or full of air.

The system is not drawing air from the tank. ( I closed the valve to the compression tank and the air production continued as the system pressure raised)

Unknown

With all this experience,,,

have you never smelled vented air before?

Usually it is black(like ink),,,, very tough to wash-off.



As I stated before, air has to coming from somewhere else and binding the pumps,,,, of course you know that don`t you.  

Steve Whitbeck

stinkey boiler water and air production

Dave there is nowhere for the air to get in.

using a stethescope the only place I hear air is in the supply line from the boiler.

No air in the system return or the return to the boiler.

Air sep. is after the boiler supply.

If the air was coming from somwhere else then WHY doesn't the air start untill the boiler hits 170* ???

Mark Eatherton

Could it be Hydrogen?

Easy enough to figure out if it is. Try closing the auto vent, then hold a Bic lighter next to it when you open it to release it. If it flares, it's hydrogen.



Not sure, but I think the production of hydrogen is related to the pH (potential Hydrogen) of the water...



ME

Steve Whitbeck

stinkey boiler water and air production

There isn't an auto air vent. System has a compression tank. I could test at the relief valve.

So lets say it is hydrogen.

Will flushing bleach through the system git rid of whatever is in the water.

Will bleach 50 to 1 harm the pumps???

Mark Eatherton

Not sure about the bacteria idea...

Bacteria numbers generally decrease at higher temperatures,



Check the pH of the system fluid. If it is high, consult a water treatment specialist for chemicals that you can add to correct the waters pH.



7.6 to 8.5 is considered ideal for conventional system metal components (Steel, copper and C.I.)



Be careful with the Hydrogen and flame. My neighbor singed the hair off of his arm last week doing the same thing.



ME

mars_6

Potential for growth

Would not the compression tank be an ideal area for the growth of unwanted guests to the system, it would seem to me that the temps would be more favorable to unwanted bacteria within the system. Just a thought. Matt    

Mark Eatherton

Missing major components...

Hi Matt,



In order to maintain and sustain bacterial life, the bugs need food, water and oxygen. If any one of those three components is missing, life ceases.



I still owe you lunch .



ME

Jean-David Beyer

anaerobic bacteria

"In order to maintain and sustain bacterial life, the bugs need food, water and oxygen."



There are such things as anaerobic bacteria (that do not need, or are harmed by, oxygen. IRRC, the one that cause botulism is one such. I do not know about the ones that cause stinky boiler water.

Mark Eatherton

That's why I am a plumber and not a biologist.... ;-)

Also forgot to mention iron consuming bacteria. If these are present you will be able to identify them from the red/orange water characteristics, and those bugs can be ealt with using Clorox.



When I mentioned food, water and oxygen, I forgot to mention "ideal temperatures for growing conditions". These criteria are the ones used for the bacteria that I have most of my personal experience with, that being legionella pneumophila.



ME