I'm suspicious of this Prach guy though... a self-proclaimed heat exchanger expert, and evidently pontificates--in his seminars he holds all over the country training HVAC techs--that he can even find leaks in a heat exchanger that's 3 years old. His seminars are apparently quite hands-on and he travels with several actual heat exchangers and demonstrates trouble spots on each. I've talked to two attendees and they concur on these points.
So, do y'all think this is a worthwhile diagnostic test that correlates with real safety issues, or just a great way to sell new furnaces and make this Prach guy rich giving seminars from companies so willing to have him teach techs to find leaks in 3 year old heat exchangers?
The whole thing seems to hinge on the assumption that if the heat exchanger isn't water tight, then it isn't air tight, and the further assumption that pressures inside the furnace are such that combusion byproducts might actually make it into the airflow of such leakage areas.
My own situation that motivates the question: a tech (from a significant, well-respected company in Chicagoland that I've used for years because they invest in training their techs rather well) had attended a seminar by this man recently, and had come to give my 15 year old Carrier furnace the annual cleaning and once over. Perhaps it was the age of the furnace, or the rust on it from the prior owner not occupying hte house for the prior two years, but soething compelled him to drop the blower and perform this new test he'd learned recently. Now, this is a furnace that had a visual inspection and tested CO free on all chambers last November for whatever that's worth. I understand that for CO to form and get into ducts you need a lot more than an HX breach.
Personally, I may go ahead and replace the furnace based on age and the suspicion alone, and enjoy the comfort and efficiency afforded by a newer 2-stage and/or variable speed furnace since my time horizons in this home are long enough to get the payback.
But I remain curious what folks think about this test all the same, and the likelihood that my current furnace _really_ has a safety concern.
Thanks in advance for any constructive thoughts or discussion.
Best Regards, -- Todd H. http://www.toddh.net /