I had a HVAC guy come out and look at my furnace for me. Does some short cycling thing. He found a crack in the heat exchanger assembly. So I have a home warranty that was included with the house. So their guy came out and did a Co check and such. Say no CO is detected outside of unit. So they will not cover it since they can't find any "abnormal" CO around unit. What is your guys thoughts? here is a pic of the crack. I feel i'm getting the run around. The preferred provider was a no call no show for 4 days till I finally said WTF you guys showing up.
Heat exchanger crack thoughts
- Thread starter mrrooG8
- Start date
Warrenator
Well-known member
If the unit doesn't run correctly, it is broke. The CO test is a red herring.
They could not get the short cycling concern to act up. He was there an hour. I said it doesn't do it all the time. The furnace seems to be working mostly normal besides the short cycle at times and the shown crack. He says the crack is not per say in the heat exchanger it's self. Then he goes on to say I have a estimate for you for replacement of the furnace if you want to go that route.... Is that saying something? I'm not a pro HVAC guy but I think i'm getting run around??
Typical home warranty -- they never want to pay and when they do it's the cheapest possible route ... using hacks. Rant over.
That looks like a crack -- did the first guy say the unit was short cycling because of the crack? or did he notice the crack and say you need a new heater .. and not really look at why the unit was short cycling?
Some units have a flange that directs the air/ gas into the exchanger ... it's not part of the heat exchanger. I really can't tell what you have.
You will have to get your warranty out and read it -- see what they will actually pay if you do need an exchanger. I'm sure the exchanger is not worth exchanging.
Has the unit always short cycled -- it may be oversized? I'm trying to think what would turn off a unit with a crack that small -- I bet it's short cycling for another reason.
The heat exchanger is what the flame goes through on it's way out of the flue -- the exchanger transfers the heat to the house. Any cracks or holes will allow the flue gasses to be drawn into the house -- can't have. The warranty guy was testing for these gasses -- I guess the crack does not go into the exchanger or it's small .. or his tester did not work. You need to do some more investigation.
I would call the regular HVAC guy up and see if you can get some more information
That looks like a crack -- did the first guy say the unit was short cycling because of the crack? or did he notice the crack and say you need a new heater .. and not really look at why the unit was short cycling?
Some units have a flange that directs the air/ gas into the exchanger ... it's not part of the heat exchanger. I really can't tell what you have.
You will have to get your warranty out and read it -- see what they will actually pay if you do need an exchanger. I'm sure the exchanger is not worth exchanging.
Has the unit always short cycled -- it may be oversized? I'm trying to think what would turn off a unit with a crack that small -- I bet it's short cycling for another reason.
The heat exchanger is what the flame goes through on it's way out of the flue -- the exchanger transfers the heat to the house. Any cracks or holes will allow the flue gasses to be drawn into the house -- can't have. The warranty guy was testing for these gasses -- I guess the crack does not go into the exchanger or it's small .. or his tester did not work. You need to do some more investigation.
I would call the regular HVAC guy up and see if you can get some more information
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sms1974
Well-known member
That crack in the front vestibule is not a huge issue, what is a huge issue is how that crack got there. Follow along... each of the openings in to which a burner goes in to is referred to as a cell. each cell is made like a clam shell when you heat these up the metal expands and contracts when it cools, this movement over time is what causes cracks. in order for the front vestibule to crack there has to be heat and pressure from expansion applied there. In a furnace that is operating properly there should not be either of those at that location. That is usually caused by a restricted cell, meaning there is not enough draw through that cell and you get heat back out the front. sometimes you will also see that happen in a standing pilot furnace directly above the pilot. either way you have an issue and in reality the fix is a new furnace. but your in an up hill battle to get a home warranty company to pay for any of it. I always make a call to the home warranty co. with the homeowner and on speaker phone. good luck
btdobie
Well-known member
I sure as heck wouldn't want to spend longer than I had to in a house where the furnace had a cracked exchanger, but I can be a bit of a safety nut. Would the guy from the warranty company be comfortable with that furnace around his family?
If there is a crack in the exchanger, most HVAC techs will want to replace it. It's not just because they get money for doing the job, but also because they don't want to be on the hook if the crack grows and someone gets CO poisoning.
That being said, that crack may not be in the exchanger as yeldogt said.
If there is a crack in the exchanger, most HVAC techs will want to replace it. It's not just because they get money for doing the job, but also because they don't want to be on the hook if the crack grows and someone gets CO poisoning.
That being said, that crack may not be in the exchanger as yeldogt said.
The previous replies bring up some good points.
Having had a cracked heat exchanger when I was young I tend to be overly cautious regarding these situations. ( I left for school early and only suffered a substantial headache, my sisters both passed out and my mother went outside to get help and passed out falling off the front porch. Fortunately a neighbor saw the fall and called for help--no one died, but came very close) Not whithstanding the battle with the home warranty people, could you live with a worse case scenario where something happens to your family? Is it worth the cost of that new furnace to avoid it?
In any case I would get a carbon monoxide detector (one that give the percentage of CO in the air as a readout in addition to an alarm) right away.
Just playing devil's advocate. I hope you get this situation settled soon
Having had a cracked heat exchanger when I was young I tend to be overly cautious regarding these situations. ( I left for school early and only suffered a substantial headache, my sisters both passed out and my mother went outside to get help and passed out falling off the front porch. Fortunately a neighbor saw the fall and called for help--no one died, but came very close) Not whithstanding the battle with the home warranty people, could you live with a worse case scenario where something happens to your family? Is it worth the cost of that new furnace to avoid it?
In any case I would get a carbon monoxide detector (one that give the percentage of CO in the air as a readout in addition to an alarm) right away.
Just playing devil's advocate. I hope you get this situation settled soon
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Dr Stan
Well-known member
I could not agree more. Every where I've lived a cracked heat exchanger = condemned furnace, period. Get a legit HVAC tech over there ASAP to condemn the unit. Notify the "home warranty" company they have 24 hours to change out the furnace under warranty or there will be legal consequences. When they fail to do so have it changed out. If necessary finance it through the HVAC company or the gas company which ever is best for you. Document everything especially the notice to the HW outfit. E-mail them and/or send the notice via registered mail, or both.
Then prepare for a civil suit, no I'm not kidding. See if it could be heard in small claims court. The size of the suit all depends on the state you live in. If you have to go to civil court get an attorney and make sure the settlement includes all court costs & attorney fees.
There will be those who insist its not worth the suit, but think about all the other people who will get screwed over if they are not held to the contract. When I had a car wreck about 3 yrs ago the only way I could get the SOB's at the offending driver's insurance company off dead center was by hiring an attorney.
I too had a home warranty purchased by the previous owners. Not worth the trouble. When I had some plumbing issues they would not even send someone to look. I made the repairs myself and told them to F off when they tried to sell me additional coverage.
bczygan
Well-known member
Around here they red tag a crack and you have to replace it.
It is very possible to have a cracked heat exchanger with no CO in the air, if the furnace is operating properly the CO levels are very low, the problem occurs when something happens and the furnace is no longer operating correctly and it produces a high level of CO.
FWIW I've never ever had a manufacturer deny warranty on a heat exchanger that has even the tiniest crack in it anywhere.
If you're on natural gas I bet the gas company would be more then willing to red tag that unit and require replacement. The home warranty company will still put up a fight and will likely do everything they can to not pay, it's how they work.
FWIW I've never ever had a manufacturer deny warranty on a heat exchanger that has even the tiniest crack in it anywhere.
If you're on natural gas I bet the gas company would be more then willing to red tag that unit and require replacement. The home warranty company will still put up a fight and will likely do everything they can to not pay, it's how they work.
zmaxmotorsports
Well-known member
I used to go around and around with our local trane supplier here in omaha over cracked heat exchangers in 80% furnaces.
They didn't want to warranty cracked heat exchangers unless there was a hole size of your fist punched through them.
I told them if they were cracked they were cracked,and I wasn't going to chance a family getting killed over their f'd up design on the heat exchanger.
They were always cracked in the same place,so yes it was a design screw up.
So we finally told them if they gave us any more grief about warantees that still had 10 years left on them for heat exchangers a flier would be sent to every house in a certain sub division where I new of several hundred of the same furnaces had been installed.
The fliers would offer a free heat exchanger inspection,suddenly their piss poor attitude changed.
So anyway don't let those *** clowns play games with a bad heat exchanger,tell them you want it fixed or else.
They didn't want to warranty cracked heat exchangers unless there was a hole size of your fist punched through them.
I told them if they were cracked they were cracked,and I wasn't going to chance a family getting killed over their f'd up design on the heat exchanger.
They were always cracked in the same place,so yes it was a design screw up.
So we finally told them if they gave us any more grief about warantees that still had 10 years left on them for heat exchangers a flier would be sent to every house in a certain sub division where I new of several hundred of the same furnaces had been installed.
The fliers would offer a free heat exchanger inspection,suddenly their piss poor attitude changed.
So anyway don't let those *** clowns play games with a bad heat exchanger,tell them you want it fixed or else.
Dirtydan69
Well-known member
Who supplied the home warranty? Your Realtor or the sellers? I would have a conversation with that person. They may have a good relationship with the area rep for the company. I had such a relationship with my area rep when in illinois. It helped with getting things approved.
Ohmthis
Well-known member
I agree with brewchief, a crack doesn't always mean it's trashed. If no CO readings crack isn't a issue....now. I would contact the gas company or another HVAC contractor that will red tag the unit and go that route. They would have to fight the reason it's ok. Court may be your only real option if they continue to bend you over. Good luck and let us know how it goes.
mrobins297aaa
Well-known member
This.......
some things to consider if you have a small crack the air is likely to travel into the heat exchanger and not into the room air, remember the inside of the heat exchanger is a negative pressure and the room air is under a positive pressure.
where you can get into trouble is if you have a big enough of a crack in the heat exchanger the air from the furnace blower can travel into the heat exchanger actually cause the flame to roll out of the heat exchanger and cause problems like tripping a roll out switch which would act like a short circuit.
your best bet is to call the gas company they don't have a chip in the game and they have to red tag it if it's a issue, but be prepared to be without a furnace if they do.
remember it's not the products of combustion from nat gas that kill you it's when they don't get enough air for complete combustion that they produce CO.
Think about it you don't have a flue on your gas stove and as far as I know it hasn't killed anybody yet.
Third party warranty companies are notorious for promising the world, and after they get your money find 101 ways to deny your claim. In my 30 years of working on gas furnaces I found many cracks in heat exchanger's - but not every one of those units tested positive for CO. AT THAT MOMENT. You're taking a snap-shot. Just because it's clear then doesn't mean it won't leak later.
Do you want to take that risk - with your family?
If the HVAC tech who found the crack is a licensed contractor, then have them call the warranty company. Get it on record that they refuse to repair a cracked unit. No guarantee they'll do anything. I got refusals from warranty companies all the time. That's why I never recommended people use them.
Do you want to take that risk - with your family?
If the HVAC tech who found the crack is a licensed contractor, then have them call the warranty company. Get it on record that they refuse to repair a cracked unit. No guarantee they'll do anything. I got refusals from warranty companies all the time. That's why I never recommended people use them.
My suspicions have been right so far. HVAC guy is screwing me around. He never even called the claim into the home warranty company. He told me last night the claim was denied. But he was quick to have an estimate for a new furnace and install ready. Warranty company told me it is covered. I hate having to call someone out. But in this case it's a must. Now I have to have a 3rd company come out and say their recommendation. So that's where i'm at now.
Actually -- when the blower turns on the flow of air creates a negative pressure on areas of the heat exchanger -- a crack in the correct spot will draw combustion gasses out of the exchanger and into the house.
Also, since most modern furnace have air induced combustion -- the exchanger is positive pressure > atmospheric combustion.
The OP needs to have to unit checked again -- or have a discussion with theHVAC company. I agree .. they are supposed to red tag a unit that has an actual crack. That has me wondering what the flange is ?
Also, since most modern furnace have air induced combustion -- the exchanger is positive pressure > atmospheric combustion.
The OP needs to have to unit checked again -- or have a discussion with theHVAC company. I agree .. they are supposed to red tag a unit that has an actual crack. That has me wondering what the flange is ?
Motown
Well-known member
I was going to say the same thing. Since your in Michigan. Have Consumers, or DTE come look at it. And they will condemn the unit. That will force the Warranty Company to replace it.
zmaxmotorsports
Well-known member
sms1974
Well-known member
You are 100% wrong here...
The draft induction venter creates a negative pressure inside the heat exchanger. This is how the use of in shot burners is possible the burning gas and air is actually sucked in to the heat exchanger all the way through it and then blown out the exhaust vent.
the last furnace I know of made with a positive pressure heat exchanger was the Lennox Pulse AKA the biggest POS ever made, which was involved in a class action lawsuit.
sms1974
Well-known member
I've been a Trane dealer since Trane was born, its actually an evolution from General Electric, I've never had an issue or resistance from Trane over any heat exchanger replacements. They have even gone so far as to replace heat exchangers that were plugged with soot which is not a manufacturing defect.
Carrier on the other hand used to have a 7 page unit information document that they required filled out with exact measurements taken by a specific CO meter ( a Testo 327, which cost over a grand at that time ) and photographs then they would decide if they would cover it and what they would send you. in other words you had to disassemble the entire furnace document it submit it and then wait for an answer a week or more later. Do you think anybody was doing that??? no 90% of them bought a new furnace and it wasn't a Carrier...
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Here is he pics I took just now. I'm not sure if it's ok or not? Looks to be on the outside mostly. I got a mirror out and looked around but could not see much. If it's safe that's fine. If not I'd like to know for sure. 
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vettex2
Banned
do you really think they haven't a strategy for these scenarios?I could not agree more. Every where I've lived a cracked heat exchanger = condemned furnace, period. Get a legit HVAC tech over there ASAP to condemn the unit. Notify the "home warranty" company they have 24 hours to change out the furnace under warranty or there will be legal consequences. When they fail to do so have it changed out. If necessary finance it through the HVAC company or the gas company which ever is best for you. Document everything especially the notice to the HW outfit. E-mail them and/or send the notice via registered mail, or both.
Then prepare for a civil suit, no I'm not kidding. See if it could be heard in small claims court. The size of the suit all depends on the state you live in. If you have to go to civil court get an attorney and make sure the settlement includes all court costs & attorney fees.
There will be those who insist its not worth the suit, but think about all the other people who will get screwed over if they are not held to the contract. When I had a car wreck about 3 yrs ago the only way I could get the SOB's at the offending driver's insurance company off dead center was by hiring an attorney.
I too had a home warranty purchased by the previous owners. Not worth the trouble. When I had some plumbing issues they would not even send someone to look. I made the repairs myself and told them to F off when they tried to sell me additional coverage.
danski0224
Well-known member
That visible crack in the pictures is not a cracked heat exchanger (HX).
That furnace is not induced draft, I'd guess early 1980's manufacture at the latest... over 30 years old at this point. Probably time to replace it.
There is no way to visually check 100% of the HX without being able to look at 100% of it, which typically means removing it from the furnace cabinet. Consumer grade borescopes (less than HD resolution or not visible infrared) do not have good enough resolution to accurately judge anything but something that is really obvious.
The first few visible inches of the HX certainly look rough. I would definitely pull the blower housing and look at the HX from underneath. Some techs have long mirrors cut to slide into the space where the burners are for a visual inspection.
CO from a cracked HX may not necessarily enter the supply airflow due to positive pressure exerted by the circulating blower pressurizing the HX cells and forcing the flue gases up the chimney. Too much additional pressure could force flue gases out of the dilution hood and then into the living space or cause rollout switches to trip- if that furnace has those (I see one).
I'd guess that the crack in that cover piece is caused by flame rollout.
Home warranty companies provide a worthless service.
That furnace is not induced draft, I'd guess early 1980's manufacture at the latest... over 30 years old at this point. Probably time to replace it.
There is no way to visually check 100% of the HX without being able to look at 100% of it, which typically means removing it from the furnace cabinet. Consumer grade borescopes (less than HD resolution or not visible infrared) do not have good enough resolution to accurately judge anything but something that is really obvious.
The first few visible inches of the HX certainly look rough. I would definitely pull the blower housing and look at the HX from underneath. Some techs have long mirrors cut to slide into the space where the burners are for a visual inspection.
CO from a cracked HX may not necessarily enter the supply airflow due to positive pressure exerted by the circulating blower pressurizing the HX cells and forcing the flue gases up the chimney. Too much additional pressure could force flue gases out of the dilution hood and then into the living space or cause rollout switches to trip- if that furnace has those (I see one).
I'd guess that the crack in that cover piece is caused by flame rollout.
Home warranty companies provide a worthless service.
rburke65
Well-known member
They will sign a different tune when everyone wakes up dead some morning.
chrispyny
Well-known member
Send a registered and certified letter to the home warranty company. Advise them of what is found, and that you have forwarded the findings and condition of your furnace to your attorney and home owners insurance. Tell them if something goes wrong, or someone is hurt, they are on the hook, having declined to replace the furnace under warranty.
Let's see how long it takes for them to pay out for a new furnace.
Let's see how long it takes for them to pay out for a new furnace.
Brian_WK
Well-known member
X10 I hate pulse furnaces. Except the first stage heat exchanger makes a good pulse jet....
Brian
99LeCouch
Well-known member
Glad to hear the warranty company is playing ball at this point. There are sketchy service providers in every field. Sad to hear you got one. Hope the next person out is better.
Pressure is relative -- with a true negative relative pressure the flue gas could never escape. We know this to be incorrect. The negative pressure relates to the static atmospheric pressure .. not the pressure around the heat exchanger.
zmaxmotorsports
Well-known member
zmaxmotorsports
Well-known member
Pull the burners out and look up inside the actual heat exchanger with a flash light and a mirror,I bet you'll find more problems.Here is he pics I took just now. I'm not sure if it's ok or not? Looks to be on the outside mostly. I got a mirror out and looked around but could not see much. If it's safe that's fine. If not I'd like to know for sure.
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Shine a light on to your mirror and look directly above the area of that outside crack.
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Well second hvac tech came out and looked. He said crack is fatal. Recommended furnace replacement. He saw the short cycling thing it does also. And humidifier is inop. Guy knew what he was talking about and was honest. That's the big thing. He will call the home warranty company and tell them his findings. He uses American standard products. Anyone familiar with those? Looks like reviews for any manufacturer is hit or miss...
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zmaxmotorsports
Well-known member
American standard/trane.
Well they are replacing it. I knew it was a issue. I asked about upgrading from the base model. They want $900 extra to upgrade from a 95% silver 95 model to a 97% gold model. The upgraded model has variable speed motor and a couple other things. Is it worth it? $900 seems a lot. I can't find any pricing online.
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That looks to be an upgrade from a single stage to a 2 stage variable furnace, if so that upgrade cost is pretty close to what we charge for the same upgrade.
I always recommend adding a good media air filter during a furnace replacement, 99% of the jobs I do get one.
rsanter
Well-known member
Send them a picture of the crack and ask them how they handle things when it gets worse and leaks CO2 and kills your family?
Bob
Bob
sms1974
Well-known member
As said American Standard and Trane are one in the same, Ingersoll Rand now owns them. Best equipment on the market in my opinion. As for the upcharge its pretty reasonable, my actual cost difference between the 2 models is right at 600 dollars.
Radix2
Well-known member
Well, the pros say the charge is typical. Fine. Is it worth it? $900 for a 2% bump in theoretical efficiency ?
No way, unless you really have easy money or highly value running the fan all the time and having variable speed to play with.
1. It will never pay back cost wise.
2. Odds are you will never notice any difference in operation.
No way, unless you really have easy money or highly value running the fan all the time and having variable speed to play with.
1. It will never pay back cost wise.
2. Odds are you will never notice any difference in operation.
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