Posted by Tony Conner on October 23, 2001 at 12:42:21:
In Reply to: sulfer buildup in stack posted by Jim on October 23, 2001 at 10:42:50:
The deposit is likely sulphur from the fuel. That doesn't necessarily mean you're being supplied the wrong grade. I'd suspect flue gas temps after the economizer that are in the condensing range.
Check the flue gas temp after the economizer to see if it's too low. Does the water side of the economizer have a 3 way valve to recirc some water to maintain a minimum flue gas temp?