Havent seen this yet...

**Marc M** · 01-29-2011, 08:17 AM

Got too hot? Looking for opinions on this issue.

**Scott Patterson** · 01-29-2011, 10:06 AM

Originally Posted by Marc Mazza

Got too hot? Looking for opinions on this issue.

No, getting too hot did not cause that.

That is just an old gas furnace that is toast and needs to be replaced.

**Nick Ostrowski** · 01-29-2011, 10:23 AM

A large percentage of the byproduct of burnt gas is moisture. The moisture is acidic and corrosive and will start to break down masonry as well as metal. What your pics show appears mostly to be the result of years of use and condensate condensing on the metal surfaces. How old was the furnace?

**Marc M** · 01-29-2011, 10:27 AM

Originally Posted by Nick Ostrowski

A large percentage of the byproduct of burnt gas is moisture. The moisture is acidic and corrosive and will start to break down masonry as well as metal. What your pics show appears mostly to be the result of years of use and condensate condensing on the metal surfaces. How old was the furnace?

Hey Nick,
Its a 1986 furnace. That makes total sense. Dont know how come I havent seen anything like it before yesterday.
Question. I go into this track all the time and have never seen this on any other unit. Anything within a typical furnace that may accelerate this occurence with any one unit (like this) as opposed to others?
Thanks for your input, very helpful.

**Nick Ostrowski** · 01-29-2011, 11:15 AM

Originally Posted by Marc Mazza

Hey Nick,
Its a 1986 furnace. That makes total sense. Dont know how come I havent seen anything like it before yesterday.
Question. I go into this track all the time and have never seen this on any other unit. Anything within a typical furnace that may accelerate this occurence with any one unit (like this) as opposed to others?
Thanks for your input, very helpful.

It could be a number of things. There could be something affecting the way the unit drafts like the sizing of the flue pipe or the number of bends in the pipe. There could be something else within the same room or area that is competing with the furnace and creating more of a draw and slowing down the unit's draft. I see a lot of older forced air systems that have multiple unsealed gaps and seams on the return ducts, no cover on the air filter bay, and poorly installed filter bays and return ducts with large open gaps where the return connects to the furnace cabinet. If you have enough gaps and openings like these next to the furnace, it can be same as having an open return vent too close to the unit. If that's the case, the furnace is essentially fighting against itself. Natural draft will lose when in competition with a mechanical draw like the fan blower on a furnace.

**H.G. Watson, Sr.** · 01-29-2011, 02:48 PM

Where is the water heater and its vent?

Do I see several inches of dark insulating roof goop slathered on at the cowl & vent? instead of the missing storm collar/drip ring?

What's the specifics on the furnace - draft fans, etc. defeated? efficiency? subject to a venting recall?

Never having the unit serviced, short cycling, bad thermocouple, things that come to mind.

Should be condemed, red-tagged, Danger.

Ted Menelly · 01-29-2011, 03:40 PM

Originally Posted by Marc Mazza

Got too hot? Looking for opinions on this issue.

I have an answer for you but others have already stated possibilities.

I do have a better answer though.

It does not matter. The system is wasted and needs replacing so when they do.....problem solved.

**Marc M** · 01-29-2011, 05:32 PM

Originally Posted by Ted Menelly

I have an answer for you but others have already stated possibilities.

I do have a better answer though.

It does not matter. The system is wasted and needs replacing so when they do.....problem solved.

Well stated Ted. I cant argue with that.

Thanks for the input Nick, very helpful.

**Terry Beck** · 01-31-2011, 11:50 AM

As previously stated - age, possible poor drafting, and lots of water vapor in the combustion. Except for the last picture, I would have guessed it was an older furnace from the 70s. Is this installed in a damp basement, near other appliances or plumbing that may have had chronic leaks/condensation, water heater, or a nearby laundry area? Probably never adjusted and maintained. I would not necessarily state that it was at end of life, but would recommend review by a HVAC pro based on age and appearance alone.

**Mike Clarke** · 01-31-2011, 05:12 PM

have seen many older systems with A/C that had metal drain pans on the evap coils in a vertical installation fail and condensate leaking down into the guts rusting and compromising the furnace.