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deccher 01-08-2009 12:20 AM

Replace Heat Exchanger or Furnace
I have just been told I have a bad heat exchanger in my GMP125-4 (Janitrol, but now Goodman). I was told $400 to $600 for exchanger, and $1,100 labor. I asked how long it takes and he said 5 or 6 hours. They must think a lot of themselves, demanding over $180 for the work. I found the part on-line for just under $300, and apparently most HVAC work can be done for around $85 per hour. I am planning to get several other estimates. Point being, I am looking at a minimum of 5 hours at $85/hr + $300 for heat exchanger = $725. More realistically I will get estimates for $800 to $1,000 total, I am guessing.

The same HVAC company did their free sizing on my house and figured I need a 115 BTU furnace with a 5 ton blower (house is finished basement + 2 story, total SF of 3,250). He recommended the 95% efficiency Goodman GMV-95-115. He was offering the "one time only price" of $5,892 installed.

Given my yearly averaged gas bill is $103/mo, including my water heater, a 15% efficiency gain would take forever to pay for the new furnace. If I save roughly 15% on my bill (going from 80% to 95% efficiency), and assume the whole $103 is the furnace, I save a grand total of $180/yr.

It seems a no brainer to me to fix my existing furnace for around $1,000. Does anyone have any thoughts that contradict my thinking?

Could I get a new furnace from another contractor for substantially less than these guys are quoting? I am thinking the labor must be really high to put in this furnace, given I found the exact model on the Internet for just under $1,600. See

Thank you for taking the time to read this and reply.

beenthere 01-08-2009 05:46 AM

As contractors. We charge what we need to stay in business, and to of course pay employees.

So, many of us are well over 85 bucks an hour.

Get some other estimates.
A one time price offer, is a good sign to call some one else.

Since your GMP seems to be over 20 years old.
Get quotes on other brands also.

A 95% may only work out as a 15% savings on paper.
But, most come out saving more then that(and yes, some less).

A new unit will come with at leat a 20 year HX warranty, and a 5 years parts warranty on the other furnace parts.

10 years from now, is your gas going to cost the same as it does today?

Home Air Direct 01-08-2009 09:47 AM

+1 for everything BEENTHERE offered:thumbsup:

If you do decide to go with a new furnace, you may consider going with a standard blower motor 93% efficient setup instead of the Variable Speed. There is usually a considerable price difference between the VS product and the standard. Your current furnace is standard and if that has served you well in relation to comfort, then you should be fine. I am often suspect when contractor want to put VS units in older homes.

On the subject of replacing the heat exchanger. I am an HVAC contractor, so I am all about new equipment, but different folks have different philosophies about repair versus replacement. Since you already have a very reasonably low gas bill, your decision should probably be based on your immediate and available finances. Every time one of my adult children complains to me that they are going to have to repair their car and the cost will be $500, they will try to rationalize a new car by thinking it would be better to apply that $500 in payments. I always respond by reminding them that they only have to drive the car for 1 1/2 months to justify the $500 repair.

If you do buy the heat exchanger online, you may want to offer the contractor of your choice an incentive since he will be unable to profit from the parts sale. If the going rate for his work is $85 an hour, maybe an offer to pay $100 an hour for his services would not be unreasonable. The total cost to you would be at max. An additional $75. The reality is this repair should only take 3 to 4 hours.

I often see homeowners beat up by contractors when these types of questions are asked. The reality is, it is your money and you should decide how when and where you spend it. You also are responsible for the outcome of your decisions.

Good luck to you.

jogr 01-08-2009 04:03 PM

Call Goodman with the model # and serial #and see if your heat exchanger is under warranty. Mine was so I didn't have to pay for the part. However I did have to pay for the labor. If your heat exhanger is still under warranty (Goodman is lifetime) your contractor might not realize it so you might actually have to tell them (I had to tell mine).

Most HVAC companies would rather sell you a new furnace so you might need to call a few to find the best install price. But make sure you go with a reputable company - a low price isn't any good if it's done wrong.

You might not actually be able to buy a heat exchanger online unless you are a licensed HVAC contractor. I couldn't find anyplace online that would sell me the heat exchanger instead of a licensed contractor. Goodman would only allow a licensed HVAC dealer to receive the replacement exchanger under their warranty. If you do end up finding one you may find that local HVAC contractors won't want to touch it since they have no control over what you are giving them to install.

I ended up paying $650 labor for mine but I'm in a somewhat rural midwest area where cost of living is fairly low. The $1100 estimate might be very reasonable for your area. It really does cost a lot to run a business - much more than just paying an employee his hourly wage while he's at a customers house.

You want to make sure you replace a bad exchanger right away cause they can be deadly and make sure you have good carbon monoxide detectors.

Good luck

beenthere 01-08-2009 04:07 PM

I'm pretty sure, GMP HX's are only 20 year limited warranties.

SKIP4661 01-08-2009 05:32 PM

What is the serial number? If its under warranty Goodman has a program where your furnace can be replaced with a newly designed furnace for about what you were quoted for labor for htx.

deccher 01-09-2009 04:30 PM

Thank you all very much for your responses. Your advice is appreciated.

So much has happened in the past three days, but I want to share it for the sake of others. I’d also appreciate your recommendation on my course of action.

My house was built in 1998 with the Janitrol / Goodman GMP125-4. With some checking, the furnace was actually manufactured in 1993. Furnace S/N is 9702854654.

I called an HVAC Contractor on Wed evening. He came out and assessed my furnace as follows "Found 4 big cracks on the heat exchanger, 1" to 2" in size coming off eyelets letting bi-products into air stream. Very unsafe to run." This is written on my receipt, and he basically told me the same thing. He then pitched me furnaces, with the "premium level" 95% Goodman 2-stage, variable speed coming in at $6,700 installed. I believe the 80% much like my current one, but with variable speed blower was quoted around $4,000. These are installed prices with any applicable duct/venting work.

I then user to set up 3 appointments for the following day, and set up one through Home Depot's services group. NOTE: Quality Smith set up the appointments only 1 hour apart, you really need a minimum of 2 hours to get new furnaces sized and quoted. Needless to say, my house looked like that Lone Tree commercial with all those lenders standing around to make their offer. Rude, but also a little commical. I told them to let QualitySmith know what happened.

Anyhow... The first contractor started to put together a quote, and I mentioned I would feel a lot better if I had a second opinion on the heat exchanger really being bad. They brought out a tech who used a CO sniffer to sniff the output air (small hold in duct right above furnace) and several heat registers. No CO measured (gauge starts measuring at 1 ppm). I asked them to go ahead and quote me an 80% and 90% plus furnace, just in case, but informed them I understood if they were unwilling, given I could be wasting their time if no replacement was needed. They complied and quoted me:
80% -- Comfortmaker VS 80 (C8MPV125J20C) variable speed 2-stage furnace with a non-programmable 2 stage thermostat for $2,000 installed (parts, labor, and tax).
90%+ (as they show on quote) -- Comfortmaker VS 90 (CPMPV125L20D) variable speed 2-stage furnace with a non-programmable 2 stage thermostat for $2,495 installed (parts, labor, and tax).

Second HVAC Contractor (installed prices):
80% Carrier $3,982
80% Payne $3,207
95% Carrier $5,357
90% Payne $3,653
Above prices include the 10% off for signing before midnight that night, and 5% for cash. They also told me I don't need a new thermostat with a 2-stage variable speed furnace, which from what I have researched sounds wrong.

Third HVAC Contractor (installed prices)
80% American Standard 80 Comfort R Variable Stage with digital programmable 2-stage thermostat $3,200
95% American Standard 95 Comfort R Variable Stage with digital programmable 2-stage thermostat $4,800

Fourth HVAC Contractor (installed prices)
95% Trane XV-95 100,000 BTU 2-Stage w/Variable speed blower, programmable thermostat $3,860.
He pulled out documentation on the XCel Energy rebate of $120 and the 2009 tax credit of $150 and told me they will fill out the XCel rebate and send it in for me.

Finally, with all of that done, I was still concerned about whether or not I really had cracks in the heat exchanger, since there were no measurable CO emissions per the first contractor. I decided I had to call someone with no interest in selling me a furnace. I called Xcel Energy's Emergency line and they said CO is an emergency, so they sent out a tech at no charge. This gentleman was in his 50s with years of experience, and confirmed that he knows of cases where such a "selling process" had been done with no heat exchanger issue. He took his sniffer and measured at the output of the furnace (above it, just above the AC condenser) in the duct work (a hole he stuck it through), sniffed all through the furnace while running, around all the lines, etc. and then went to about 1/2 the registers in the house and several cold air returns with no presence of CO. He then went back and sniffed all around the water heater, still a reading of zero. I asked if his measurement tool was working. We then turned on the hot water so the water heater would light, and while he had the little pilot light door open with sniffer inserted, both the natural gas and CO levels went up for about 20 seconds, then fell back to zero. So, the sniffer was working, and no apparent problem with the furnace. He said that is how he would report it, but did say that there could be small cracks in the heat exchange which are not measurable from CO emissions.

Last night I read consumer reports on-line and went and bought 3 Kindle CO detectors with displays to show CO ppm measured, with a peak feature that shows highest level ever measured for the life of the device. I put one right outside the furnace door in the basement (the furnace in unfinished portion, the detector in the finished portion), one in my family room on the main floor, and one in the upstairs hallway where all the bedrooms are. None of them have come off zero on the display. I turned the furnace back on yesterday at 3 pm.

I got a call from the first contractor last night asking if I had made a decision. I expressed to the lady that I thought I was being scammed, and told her the whole story. They sent out a senior technician this morning to show me the cracks, and said if he could not, they would pay me $300 and terminate the technician. He removed the blower, then came to get me, and had me look up inside with a mirror and flashlight, and showed me what I would call very small cracks. He told me he would pull the heat exchanger so I could see them better. He took apart the furnace and called me back down 30 minutes later. Sure enough, we found not just 4 cracks, but 7. Some were 1/4" long, the longest maybe 1-1/2". I could not see that any of them would allow air to flow through them, but nonetheless there were cracks. They were not lying, but the technician had told me verbally that he measured CO at 35 ppm before he looked at the cracks, which nobody else could duplicate. He put the furnace back together in another 30 minutes. He made a call and said they could get the heat exchanger free because it was still on warranty, and put it in for $850 in labor now, rather than the $1,100 originally quoted. So, it appears their hourly rate is $425 an hour giving them the benefit of the doubt that putting a new one in rather than putting the old one back in might take twice as long.

So, apparently I have a cracked heat exchanger with no measurable CO emissions and my furnace is running as I type.

Based on the fact that I have $5,000 in my savings account and no credit cards, what would you do knowing what I know?

If you want to see pictures of the cracks, let me know. The picture files are 3 MB jpg files from my 8 mega pixel camera, so posting them in this forum is probably not the best option, but I would be happy to Email them to you.

Thanks again to all of you for your feedback.


hvaclover 01-09-2009 04:43 PM

it's an 80%er, only 20 year warranty on ex. Time for a new one

JohnH1 01-09-2009 05:06 PM

I also recomend new. The Goodman GMP units in my opinion had flaws in the design of the heat exchanger causing the rings to pop off. New will give more dependiable service than a older unit.
Rember proper installation is more important than the brand of equipment. I love the VS equipment. Costs more but well worth it in my opinion.

hvaclover 01-09-2009 05:23 PM


Originally Posted by JohnH1 (Post 210058)
I also recomend new. The Goodman GMP units in my opinion had flaws in the design of the heat exchanger causing the rings to pop off. New will give more dependiable service than a older unit.
Rember proper installation is more important than the brand of equipment. I love the VS equipment. Costs more but well worth it in my opinion.

Jesus Christ could have installed that model and it would have still died.

Just a bad design...

yuri 01-09-2009 05:43 PM

Apparently the new units are quite nice now that they brought them up to the Amana vs Goodman standards.

hvaclover 01-09-2009 05:51 PM

I agree. I am seeing my Amana guy this coming Tues.

SKIP4661 01-09-2009 07:37 PM

According to that serial# that furnace is a 1997 model. I would suggest contacting a goodman distributor, such as Johnstone Supply, to discuss the warranty options. There are options that shouldn't cost you your first born child.

Home Air Direct 01-09-2009 07:54 PM

I am going to open up my closet a little and let you know a little something about my past. I was the Vice President of a midsized wholesale distribution company who distributed Goodman/Amana throughout the state Illinois, before creating my own business.

I have very vivid memories (that felt like nightmares) of replacing over 200 GMP model Goodman furnaces between 2005 - 2007. Goodman took care of most of them, but the paperwork was a living nightmare.

Goodman changed their heat exchanger to tubes after the clamshell/rivet fiasco. They have been relatively trouble free since.

The current Goodman furnace is a decent box. Do not get all caught up in the crazy warranties that they offer up. It is an actuarial numbers game that they are playing. I will not go into to it here, but I have sat in meetings in Houston at Goodman corporate and have had to pick up my chin from the plans that Goodman has for dominating the market.

As far as which furnace to choose? There is really no bad product on the market today. The reality is that a bad install will kill a great furnace.

hvaclover 01-09-2009 07:55 PM


Originally Posted by hvaclover (Post 210048)

it's an 80%er, only 20 year warranty on ex. Time for a new one

Dhu...missed by ten years. Is still under warranty but i would still opt for a new one.

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