Does anyone know what these crystal looking things coming from chimney are?

Joseph_4

Does anyone know what these crystal looking things coming from chimney are? Is it something of a concern. One of my customers showed it to me- ive never seen such a thing before. They can be found behind the door of the cleanout at base of chimney
thx
Joe

Bob Harper

Salt crystals. Acids combine with the alkaline mortar to for soluble salts that can crystalize. Acid + base > salt + water.

EdTheHeaterMan

Byproducts of combustion have many trace chemicals that just get vented into the atmosphere including carbonic acid and sulfuric acid. Condensation of flue gasses can sometimes collect those trace molecules from the interior surface of the chimney liner. When the water mixes in with that stuff that has been accumulating for years and years, they get washed down to the base of the chimney and form crystals of all sorts of things from the chemistry department. You may have a condensation issue with your newer heater and your older chimney liner. Maybe it is time to replace that terracotta liner with a Stainless Steel liner?

pecmsg

Time to get a liner in that chimney 

Joseph_4

is there a reason this doesnt happen to everyone? many people have gas boilers that are 50 years old before stainless steel liners and automatic vent dampers came about and I've never seen this?
Joe

pecmsg

Joseph_4 said:

is there a reason this doesnt happen to everyone? many people have gas boilers that are 50 years old before stainless steel liners and automatic vent dampers came about and I've never seen this?
Joe

Old oil heat ran High exhaust temperatures.
80% gas ran high enough in Most cases.
Newer equipment runs much cooler, allowing the exhaust gasses too condense before exiting.

MikeAmann

Crystal-meth stash hiding spot.