Carrier 58MXB80 or 58MVC80

[Tang]

I am trying to decide between the two subject furnaces - the quotes I have for them put them within about $500 of each other, and I really like the idea of high efficiency. But there have been law suits regarding the heat exchanger on one - and the cost of fixing these beasts are enough to raise an eyebrow. Am I giving up long-term reliability for high efficiency? I'd like to see either of these run for 20 years, but the more I see about them, the more I doubt.

So I have come to ask the largest group of HVAC folk I know of what you know about these two - to help me choose, and to help me understand the differences and what I may be rolling the dice with. ANYTHING will be better than my current beast which is probably running at 50% efficiency at best.

What are your thoughts on these two? One over the other? What have you heard about the repair costs and how often they go down?

Many thanks in advance for your time and thought!

[DanW13]

The MX series is fixed speed blower vs. a varible speed blower the MVC has, If I were you I would upgrade to the 58MVC 96% AFUE Not sure why you only going with a 80% furnace but I don't know what region your in, but if you live in a cold climate area I would do the 96% vs. 80% which as you can see is 16% more efficent which translates inot a huge savings on your gas bill. I would suggest you also get the Infinity control no matter which piece of equipment you happen to decide on.

[Tang]

Infinity control...? Why would that be such a high priority?

I DID end up getting the 96% installed back on 11/11. Took the guys the better part of a day - half of that they were reading and that did raise an eyebrow. I also had them add a house humdifier (Skuttle) that I thought would help keep the house up about 30%. In fact I was hoping for 40 in the house - but I have yet to see it. Very dry and I suppose it was a waste of money if I was asking that much out of it. But I digress...
The furnace works well- and is a lot more quiet than the last. Cold weather is here- into the single digits F. I have had to play around a little bit with the vent dampers however. Some rooms seemed to warm up faster than others - but that was addressed over a few days.

I haven't had a chance to get a gas bill yet, so I can't speak on the savings of the unit yes. I had my propane tank filled the same day of the install.

But again- why do you stress the control unit? The installers hadn't mentioned it at all...? And I have the current programmable in place

[coolwhip]

Move the water feed line for the humidifier to the hot side, you will get much better results.

[DanW13]

The Infinity Controller will control your humidifier, zone heating if you have it, And will also keep record of fault codes if and when they happen, it also learns the way you heat your home and will learn when to kick the furnace up to 2nd or 3 stage heating depending on the heat loss of your home not just thru a time sequence like most furnace's do. IMO you would be better of just setting your set point of desired temp and leave it there unelss you use the programming features which I do to set the stat back a few degrees at night which works very nice in conjuntion with the outdoor temp sensor that is tieied into the controller(Did the installers install this ?) If not might want them to install is as it should come with the controller. The controller controls the furnace instead of the dip switch settings in the furnace itself. Maybe you need to read up on the controller or do a search here and the Infinity controller as there has been alot of treads on it in the past and will give you alot of good reading & learning. I am surprized they did not insist you get the controller with this furnace !!!

[CARRIER Pigeon]

I am trying to decide between the two subject furnaces - the quotes I have for them put them within about $500 of each other, and I really like the idea of high efficiency. But there have been law suits regarding the heat exchanger on one - and the cost of fixing these beasts are enough to raise an eyebrow. Am I giving up long-term reliability for high efficiency? I'd like to see either of these run for 20 years, but the more I see about them, the more I doubt.

So I have come to ask the largest group of HVAC folk I know of what you know about these two - to help me choose, and to help me understand the differences and what I may be rolling the dice with. ANYTHING will be better than my current beast which is probably running at 50% efficiency at best.

What are your thoughts on these two? One over the other? What have you heard about the repair costs and how often they go down?

Many thanks in advance for your time and thought!

58MXB: Highly Efficient 4-Way Multipoise Fixed Capacity Deluxe Condensing Gas Furnace Input Rates 40,000 thru 138,000 Btuh.

58MVC: Infinity ICS Deluxe 4-Way Multipoise Variable-Speed Multi-Stage Condensing Gas furnace Series 100 Input Rates: 60,000 thru 120,000 Btuh

Actually, BOTH of those models have the polypropylene laminated secondary heat exchangers that were the subject of the class action lawsuit. All it means is that you get parts AND labor covered if your secondary heat exchanger ever goes out.

You should check www.furnaceclaims.com for information on the lawsuit settlement and what Carrier is giving homeowners who have those units.

The 58MVC is the modulating, and is supposed to be the quietest furnace out of them all.

Regarding reliability: HVAC equipment is only as good as the dealer/contractor that installs it. Carrier will not help you if the equipment is installed wrong, they will only offer tech support to the installers.

I used to work for a Carrier dealer, so I may be a bit biased, but the Infinity Units are some of the most top of the line units I have ever seen. If all is sized and installed properly, I am confident that the Infinity equipment will serve you well. Just be sure your installer will stand behind their installation.

Yes the Infinity Controller is best....why get that expensive equipment without the control that was made specifically for that equipment, you know?

[mwjhvac]

You really need to purchase the infinity control. The even comfort from the blower on constant low, med, high, will really even out your rooms. It will check your filter every day. Staging will be way more efficient. read up on this on carriers website. http://www.residential.carrier.com/products/controls/infinity.shtml
You are not getting all the potential the furnace can do.

[Tang]

The Infinity Controller will control your humidifier, zone heating if you have it, And will also keep record of fault codes if and when they happen, it also learns the way you heat your home and will learn when to kick the furnace up to 2nd or 3 stage heating depending on the heat loss of your home not just thru a time sequence like most furnace's do. IMO you would be better of just setting your set point of desired temp and leave it there unelss you use the programming features which I do to set the stat back a few degrees at night which works very nice in conjuntion with the outdoor temp sensor that is tieied into the controller(Did the installers install this ?) If not might want them to install is as it should come with the controller. The controller controls the furnace instead of the dip switch settings in the furnace itself. Maybe you need to read up on the controller or do a search here and the Infinity controller as there has been alot of treads on it in the past and will give you alot of good reading & learning. I am surprized they did not insist you get the controller with this furnace !!!

Well I guess I should go back to the drawing board at researching the controller. I use my programmable thermo to raise and lower the temps while I am away or sleeping, but generally I am staying within a 10 degree spread unless I am going to be gone for a few days or more.

I have less and less faith in my local installers the more I get educated on the install. Just today I noticed that they did NOT put the humidity controller (humidistat?) on the INTAKE. But of course, it's Sunday, so I'll have to give them a call in tomorrow. Sheesh, no wonder I'm not getting humidity out of this thing - it must be shutting off shortly after the furnace turns on and it's bathed in warm humidified air!

No- they didn't install any sensor aside from the one they screwed up on the humidifier.

Are there any good links that you (or anybody) knows about to help me dig into the new controller? Something tells me that this is no $60 thermo that I could pick up at "Home Despot"... I need to know as much about how it will allow the furnace to function better as possible.

The good news is that if I decide to pick one of these up this should be a homeowner project.... right?

[Tang]

Move the water feed line for the humidifier to the hot side, you will get much better results.

That could be a very good idea. It should make some difference anyway. Will the hot water have any large effect on the rubber tubing feed, or the drum assembly?
And then I will have to deal with the pinhole in the cold water pipe when I move the saddle valve over.
For right now, I have discovered an install issue that once fixed, should help things - and maybe correct things entirely. I will take that step first, and then look to other modifications like this.

Thanks much for the fast reply!

[DanW13]

If your not sure how to repair the copper pipe just leave the saddle valve on the cold side and put another saddle valve on the hot side and connect. No you will not be able to purchase the Infinity controller yourself needs to be purchased thru a dealer/contractor but will be worth the money especially if you like to use the set back features it works really nice. Again I am surprized they didn't offer or insist you get the controller.

[Tang]

If your not sure how to repair the copper pipe just leave the saddle valve on the cold side and put another saddle valve on the hot side and connect. No you will not be able to purchase the Infinity controller yourself needs to be purchased thru a dealer/contractor but will be worth the money especially if you like to use the set back features it works really nice. Again I am surprized they didn't offer or insist you get the controller.

Good thought with the Second Saddle valve. Can't go wrong with that! You are a smart guy - being able to think "this AND That" as opposed to "This OR That".

As for the controller.. I just took a gander at this puppy - around $300? Egads! Yes I definately would need to dig into this enough to justify dropping that much on this. I will need ot know the effective differences between what I have now, and this Rolls Royce. Don't get me wrong, it looks pretty nifty, and has some features that mine does not - but at what could be ten times the pricetag, PLUS if what you say is true I have to have what appears to be a monkey install it for me I am a little leary. I'd feel a whole lot better if I knew someone around here who really DID have the technical expertise to set this up, and program it correctly. I guess this is not really a home-owner installable item just due to the correct programming between it, and the furnace itself... But I need to read up some more on the installation part.
I CAN buy it on my own - but just because a man CAN do a thing, doesn't mean he SHOULD, ya know?

[DanW13]

Ask the people you purchased your furnace from if they would give you a better price since you purchased the furnace for a good chunck of change, I believe my installer gave me close to 50% off with the purchase of the furnace.