Green goo

ernie_3

It's called dew point. Any time the emissions fall below the dew point it will condense. The greenish color you're describing usually comes from 'sox & nox' sulpher di and trioxide. Even though the unit is not firing there are still byproducts of combustion (soot...flyash...) so based on the humidity outside you'll stiil get this evil drip. I bet it doesn't drip in the winter. If it does the height of the metalbestos should be measured against the mfg requirements.

LP

Green goo

I witnessed an oil boiler making a a puddle on the floor that is eminating from where the single wall smokepipe is connected to the triple wall metalbestos. It is also staining the light colred shingles below the flashing. The unit is located in a garage and the combustion air is being taken from there(this will be changed to take it out of a vented attic). The green sbstance seems only to occur in the summertime when the boiler is not calling for heat. We did start the unit without the pump running, and for a short time the chimney did condense and a dripping started to occur from the same place. The system does have glycol but there are no appearant leaks anywhere? Why would this dripping occur when the boiler is not firing? And where would the green color come from? The switch has been off on this unit for 2 weeks and the puddle was still there. Any ideas???

Ken_8

If the boiler is a \"copper finned\" type..

It may more ominous than mere sulphur compounds leaching.

Expecially if any form of chlorides are in the make up air...

It could be the boiler block doing the sliming.

Is the boiler of the copper alloy block variety?

Teledyne, Raypak, etc.?

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DaveC

Or the flashing is...

made of copper? I just hope this thread spurs another Bill Murray (Ghostbusters this time) montage!

LP

The unit is wet base cast iron single pass.

We fired it and got more of the dreaded goo as the flue condensed on cold start. Ernie, you seem to have something there! Have you seen this before? The flashing is 3 yrs old (as is the boiler) and was made and purchased from metalbestos. You can see where this liquid is dripping from the topper onto the flashing, missing the storm collar. Then is runs off of the roof and the trail is noticeable. How does one control it Ernie? I was discussing adding another 2 ft to the chimney but I think it will still drip inside, If we ran some kerosene would the same reult occur? Please advise.

JB_2

green goo

lp- can you install a new control to let the system maintain a lower temp. during summer months.to keep things warm so they do not condense? jb

J.C.A._3

or,

Sell them a nice indirect so the keeping the boiler warm isn't being wasted.

As an almost 20 year oil tech, I won't be the fist to tell you that a warm boiler, is a happy boiler. If your gonna keep it warm, at least have a reason for it.

Just for S&G's, how do they get their hot water now? Chris

ernie_3

evil drip

Again, check the mfg specs, the chimney could be undersized either circumfrentially or height. Yes I have seen this with a cold start boiler, Peerless. I think an aquastat to maintain 1oo degrees or so. It won't cost much to keep it warm and the equipment will thank you w' it's longevity.

LP

We could very easily raise the chimney height by adding another joint of metalbestos to the top, but do you think this will stop the drip? They heat domestic with an electric tank now but we could enable the low limit,if only at 100 degrees,I might think the flue would condense more. Still confused about the green color?