I'm curious on opinions from pro's of the water test for residential
heat exchangers advocated by Ellis Prach of
http://www.heatexchangerexperts.com/ In this test, the tech pulls the
blower, douses the exchanger with a water solution from a large
sprayer, and then looks inside the combustion area for water
penetration. If there's water getting in, they reason, you have a
breached heat exchanger that they recommend replacing it.

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/