Carrier Infinity Furnace Heat exchanger shot

[Dave9]

Yeah. Enough. Sorry I asked

So you are opposed to the info you asked for, or science? I don't get your attitude at all, there's no reason to be sorry for receiving information.

Disagreement in a forum, it just happens... Pick whatever you want to believe or reject. At some point it becomes about what benefits you the most, not what someone else's ideals are.

 

[alarmguy]

I never thought about heat exchangers failing until this post, not a concern of mine, we are going on 16 years of our gas HVAC unit. Builder supplied Heil unit.

Being your unit is only 11 years old I would just replace the exchanger at any cost if there is a spread of over $1000 and if I didn't like the price I would find someone with a price I liked.
Save the money as you will most likely change out the whole system within 20 years anyway or move, which ever comes first.

I like low tech with HVAC, most other stuff is marketing for profits and any energy savings (if any) in my particular low energy cost state will be made up by higher maintenance costs or shorter life and why most likely when its time to replace I will most likely stay with Heil. Standard commercial and builder supplied product.

 

[hrv]

If you registered your furnace within 90 days with Carrier you have a 20 year warranty on the heat exchanger...

 

[Cropduster172]

I never thought about heat exchangers failing until this post, not a concern of mine, we are going on 16 years of our gas HVAC unit. Builder supplied Heil unit.

Being your unit is only 11 years old I would just replace the exchanger at any cost if there is a spread of over $1000 and if I didn't like the price I would find someone with a price I liked.
Save the money as you will most likely change out the whole system within 20 years anyway or move, which ever comes first.

I like low tech with HVAC, most other stuff is marketing for profits and any energy savings (if any) in my particular low energy cost state will be made up by higher maintenance costs or shorter life and why most likely when its time to replace I will most likely stay with Heil. Standard commercial and builder supplied product.

Yeah. Unfortunately, it's not that simple. I'm not the only one that needs that particular part...especially as it gets colder. So it could take weeks to get the part. Also, price shopping might be nice...but not when it gets down to 13 degrees Fahrenheit at night.

As I stated before, I'm not the original owner of the HVAC system. It was here when we moved in October of 2020. There is a warranty in place and I opted to take a $525 credit towards a new, single stage Payne gas furnace.

 

[alarmguy]

Yeah. Unfortunately, it's not that simple. I'm not the only one that needs that particular part...especially as it gets colder. So it could take weeks to get the part. Also, price shopping might be nice...but not when it gets down to 13 degrees Fahrenheit at night.

As I stated before, I'm not the original owner of the HVAC system. It was here when we moved in October of 2020. There is a warranty in place and I opted to take a $525 credit towards a new, single stage Payne gas furnace.

Ohhh... yeah.. your between a rock and a hard place in the middle of winter. Glad you got some credit and as you know, yeah, keep it simple.

 

[Cropduster172]

Ohhh... yeah.. your between a rock and a hard place in the middle of winter. Glad you got some credit and as you know, yeah, keep it simple.

Whichever previous owner bought this system paid a lot. I appreciate that for the AC but furnace is overkill.
A single stage furnace with a variable speed motor combined with an Ecobee wifi thermostat and perhaps I'll add an occupancy sensor to the master BR and I'll be in good shape. HVAC guy just left after taking some pics and measurements. He will check availability of several models and get back to me today and install Monday AM. I'm good with that.

 

[tbm5690]

Are.you sure 100k BTU isn't oversized? You say you're in a middle unit townhome which I'm assuming is no more than 2500 sq feet. Especially in southern PA...

 

[Cropduster172]

Are.you sure 100k BTU isn't oversized? You say you're in a middle unit townhome which I'm assuming is no more than 2500 sq feet. Especially in southern PA...

It's 2700+ living space

 

[Rand]

Not a pro but I thought it was possibly slightly oversized as well. My 1952 1250sq ft cape cod has a 60k and doesnt struggle AT ALL even on below zero high wind days.
not exactly insulated or air tight either. not to mention inefficient cape cod design.
no neighbors(town house)to help out either.

How does a 2 speed fan help with single stage furnace?

 

[Fordiesel69]

Cropduster,

There really was not a bad choice to make here....

1.) You could have had them replace the primary and secondary heat exchanger, and re-use the outlet panel and coupling box, but the tech would have had to clean the soot from them. Then it would be best for them to check the exhaust and make sure the CO and CO2 was correct. I find the ultra low heat stage on this furnace accelerates the HX failure so it is best to disable it in the infinity control. Overall one of the most quiet furnaces in the industry but the PPL secondary heat exchanger was a design that was not suitable. Mild steel coated with poly propylene laminate plastic, and then flow hot gas thru it. What could possibly go wrong here? And no the replacement HX will also fail in 11 yrs as it was not improved.

2.) Now the 59 series carrier, and PG92/PG95 series payne thankfully have a traditional clamshell primary, and a stainless tube with aluminum fin secondary like every other furnace ever built, so the new models will not have this type of failure.

Overall any brand of furnace will have hx failure when the unit is oversized.

In PA use sq ft x 8 x 4 if you have modern 2000 era or newer construction, and sq ft x 8 x 5 with 1990's or older construction. That will give you a ballpark. So 2700 x 8 x 5 = 108,000.

With yours being a center town house id be included to use 2700 x 8 x 4 = 86,400

 

[Cropduster172]

Cropduster,

There really was not a bad choice to make here....

1.) You could have had them replace the primary and secondary heat exchanger, and re-use the outlet panel and coupling box, but the tech would have had to clean the soot from them. Then it would be best for them to check the exhaust and make sure the CO and CO2 was correct. I find the ultra low heat stage on this furnace accelerates the HX failure so it is best to disable it in the infinity control. Overall one of the most quiet furnaces in the industry but the PPL secondary heat exchanger was a design that was not suitable. Mild steel coated with poly propylene laminate plastic, and then flow hot gas thru it. What could possibly go wrong here? And no the replacement HX will also fail in 11 yrs as it was not improved.

2.) Now the 59 series carrier, and PG92/PG95 series payne thankfully have a traditional clamshell primary, and a stainless tube with aluminum fin secondary like every other furnace ever built, so the new models will not have this type of failure.

Overall any brand of furnace will have hx failure when the unit is oversized.

In PA use sq ft x 8 x 4 if you have modern 2000 era or newer construction, and sq ft x 8 x 5 with 1990's or older construction. That will give you a ballpark. So 2700 x 8 x 5 = 108,000.

With yours being a center town house id be included to use 2700 x 8 x 4 = 86,400

Thanks. Good information. I went with the PG95. It's installed with a new ecobee thermostat ...100,000 BTUs. The Infinity thermostat sucked not that we require much from a thermostat.
The HVAC company did an outstanding job of installing. We've had a few 10 degree nights and a blizzard since. Temperature is perfect at 68.

 

[Fordiesel69]

I really like the features of the new ecobee 3's and ecobee 5 pro's. Their phone app is rock solid and always "just works".

 

[Cropduster172]

I really like the features of the new ecobee 3's and ecobee 5 pro's. Their phone app is rock solid and always "just works".

They installed an Ecobee3 lite and a separate humidistat on the return plenum just above the humidifier.
The 3lite measured humidity but doesn't control it. I'm OK with that.

 

[tmorris1]

They installed an Ecobee3 lite and a separate humidistat on the return plenum just above the humidifier.
The 3lite measured humidity but doesn't control it. I'm OK with that.

I have have had an Ecobee 3 for about 5 years and it works great. The external temp sensors help keep the addition in our house a little more comfortable since it can average out the temperatures between the remotes and the thermostat.

 

[Cropduster172]

I have have had an Ecobee 3 for about 5 years and it works great. The external temp sensors help keep the addition in our house a little more comfortable since it can average out the temperatures between the remotes and the thermostat.

I don't know which previous owner had the Carrier Infinity HVAC system installed. I think it was overkill for this house. Although the AC unit seems pretty stout. The Infinity thermostat required a 200 level college course to figure out. It did have the external sensor in the outside unit but I'm glad it's gone. The ecobee is simple, attractive...as far as thermostats go. It uses the wifi connection to indicate local outdoor temps from some weather site somewhere. It's fine.
Have the most basic Honeywell wifi thermostat at our beach house. It's very straightforward and is rock solid.

 

[tmorris1]

I don't know which previous owner had the Carrier Infinity HVAC system installed. I think it was overkill for this house. Although the AC unit seems pretty stout. The Infinity thermostat required a 200 level college course to figure out. It did have the external sensor in the outside unit but I'm glad it's gone. The ecobee is simple, attractive...as far as thermostats go. It uses the wifi connection to indicate local outdoor temps from some weather site somewhere. It's fine.
Have the most basic Honeywell wifi thermostat at our beach house. It's very straightforward and is rock solid.

I guess when I was talking about external temp sensors, I was talking about the small wireless sensors that Ecobee has that you can put in different parts of the house. They sense motion and temp and can be used to just display temp or be used by the thermostat to try to adjust temperature to average out between the thermostat and the remote sensors. I have one in our addition that is a long ways from the furnace and one in the basement.

 

[97prizm]

My parents original Lennox went 21 years before needing major work. I'd go that route. A cracked heat exchanger is not good. That can allow CO to leak inside the house.

 

[alarmguy]

My parents original Lennox went 21 years before needing major work. I'd go that route. A cracked heat exchanger is not good. That can allow CO to leak inside the house.

Which brings to mind, anyone who has fossil fuel burning device in their home - oil, gas, propane, wood, coal - should have at least one CO detector on each floor.

 

[Cropduster172]

Which brings to mind, anyone who has fossil fuel burning device in their home - oil, gas, propane, wood, coal - should have at least one CO detector on each floor.

This is good advice. They're are relatively inexpensive. I bought 3 at Home Depot for about $17 each.
Put one in the furnace room and one on each floor. We have a vent free gas fireplace too. Which is fantastic at heating the entire first floor of the house. But it's only about 15' from the thermostat so it effects the heat flow to the second floor. Not a big deal though.

 

[tmorris1]

We have a vent free gas fireplace too. Which is fantastic at heating the entire first floor of the house. But it's only about 15' from the thermostat so it effects the heat flow to the second floor. Not a big deal though.

That is where you can buy the Ecoboee wireless sensors to combat this if it becomes a problem. You can place the sensors anywhere within wireless range of the main Ecobee and it can use those temps (or average between thermostat and sensors) to adjust the heating and cooling. It works well for me.