Carrier Infinity Control thermostat problem

[googlemail2003]

We just had a complete new Carrier system installed. Top of the line high efficiency gas furnace (96%) and central air condenser (18 SEER). The thermostat is an Infinity Control model which is supposed to eliminate the hot/cold syndrome of forced hot air heat.

Well, it sure as hell hasn't done that. This unit doesn't recognize a change in the room temperature until it's changed by at least three degrees. That means it gets very cold before the furnace kicks on. It stays on for a long time - sometimes twenty minutes or more, then goes off for as long as an hour. It's four degrees outside right now and the furnace came on once in the past hour. When it does go on and off it "thinks" that the inside temp has changed by one degree when in fact the swing is about five degrees.

The guy who installed it agrees there is a big problem but he is having trouble convincing Carrier.

Does anyone else have a similar problem with this new model? It's very frustrating considering the little sucker cost about $400.

Thanks

Jane

[m Ransley]

So your installer doesnt know, what a pro he isnt. Is location same as old stat, maybe its a poor location or cold wall or bad stat, or getting drafts. Im no pro but am sure it has a settings for temp Swing or Anticipator if it is anything other then your basic cheap stat, it is listed under swing or anticipator settings in your stat manual. Narrow its on off range. Is it a carrier stat. You say 96%, curious what size unit because the only 96% Infinity unit is 38000 input btu from what I saw all other infinitys are around 94.5%, more marketing deception. Is your unit with the VS DC motor designed to be left on 24x7.

[jdk]

i had one installed last year and the temp reading was 2 to 3 degrees off. i called out favret co. here in cols ohio and the guy adjusted it to be right on. i use a photography therm. and it is accurate. so if they installed it they can adjust it. if not replace it period. the co. here where i live is great. also the motor saves elec.

[Dr. Hardcrab]

You need to call the installer back out and have him calibrate the thermostat. Sounds like they forgot something in the set up program...

[CBHVAC]

Or..it could just be that someone else if finding out why some of us hate Totaline... LOL

[Dr. Hardcrab]

Watchit.......

;-].

[RP]

Yes it has a problem. If all is set up and operating correctly your room temp (measured at the user interface or remote sensor, will remain fairly constant.) Does this happen to be a zoned system?

hvacrmedic

[googlemail2003]

Thermostat is in exact same spot as the old one. I'm not sure what you mean about size. I know next to nothing about furnaces. The quote says "Carrier 58 MVP 96%". Also don't know what a "VS DC" is. It does have a variable speed fan that can be left on all the time at low, medium or high and an auto setting.

My installer is going to have someone from Carrier come. He's convinced there's a bug in the thermostat. All I know is we are miserable.

[googlemail2003]

No it is only one zone.

[googlemail2003]

The installer spent about two hours here yesterday. When he first came he thought we were just some crazy complainers and that it would be fine. Within a short time he realized he was wrong. He had some fancy infra-red thermometers to read the temps in different areas. He saw that the temp would vary by as much as five or six degrees between heat cycles. It may be that he doesn't know how to calibrate it properly. He is having someone from Carrier come. Hopefully they will know more than he does.

[RP]

In that case the first order of business is to recheck connections--color coding (G,Y,W,R), tightness, etc. It's characteristic of the terminal strip in this furnace to have screws that are difficult to turn. This can lead to a tech or installer believing that the connection is tight when it isn't. I have encountered this problem more than once. It's a pin connector as well and may not be seated onto the pins all the way. Have them check the screw connections by pulling on the wires *individually*. Beyond that it could be a system fault, which should be easy to diagnose since the t-stat data-logs all faults, even runtime history, for easy retrieval. It could simply have the db set to high in the setup menu.

hvacrmedic

[jdk]

RP wrote: sorry you are having problems, but once they fix it you will be happy. i know the fan motor is expensive to replace, but does save on elec. i leave the fan on low year around. very happy with the system.

[Dr. Hardcrab]

Give us an update once they correct the problem.

Once you get it working properly, you will like it....

[googlemail2003]

What is the "db"?

The problem is the room temp on the thermostat is wrong by about three degrees. The temp in the room has to go down or up two or three degrees before the thermostat sees any change in the temp and reacts.

Would the "db" have an affect on the thermostats temp sensor?

By the way - the installer came and put in a new thermostat and it did the same thing. He also said he had two other customers with the same problem. He thinks it's a problem with the thermostat. I think it's a problem with the setup.

What do you think?

[m Ransley]

db , I dont know, maybe he meant sb or set back as in anticipator or swing, set it to the minimum Swing or Anticipator setting for now till you figure it out. It is in your thermostat manual . Or your " pro" should know the answer on the phone.

VS DC is variable speed direct current, you have it. Learn about it.

96% efficient no, I bet yours is only 94-94.5% efficient, just BS marketing as I expalined

[RP]

Deadband, the temp swing, if you will, between off and on.

It might appear to, but no. If db is set too high it will cause variations from the set point by up to the amount of db set.

That should be a valuable clue.

Unfortunately I can't see it from here.

I can't diagnose it from here based upon the minimal info that you've given, sorry. Contact Carrier yourself if you have to. The fact that he has other customers with the same problem indicates that he's either installing and/or setting up the systems incorrectly. The only settings on the controller that would cause this would be the db, already covered. If the temperature offset adjustment (a different setting mentioned elsewhere in the thread) were off by a few degrees this wouldn't result in the setpoint reading on the stat being off from the actual room temp reading on the stat.

It really sounds as though your unit is simply malfunctioning, e.g. misfiring, locking out, etc, and simply not getting the area around the stat up to the setpoint temp. This could be caused by several different installation errors involving combustion piping or indoor airflow issues. The blower speed setting may also be set incorrectly. There could be a restriction in the ductwork. The vent pipes may be too small in diameter or not sloped properly. The list really does go on and on. Best bet is to get another company out, or else get the current company to go through the installation guide page by page checking the instructions there against the actual install. If the manual is over their head then that could also account for several install issues, and unfortunately this isn't unusual in the real world.

hvacrmedic

[googlemail2003]

According to the manual for the Carrier Infinity Control unit the "deadband heat/cool" setting only controls the minimum change of temp when the unit changes from heat to cooling. There is no other deadband setting that I could find. I don't know if you have time to take a look but here is the installation guide:

We have noticed some improvement by setting the fan speed to low, but the actual room temp stills varies by two or three degrees without the change being recognized by the thermostat. Very frustrating.

Thanks for trying to help. I really appreciate it.

Jane

[m Ransley]

Did you set the anticipator or swing to minimum

[RP]

Well the deadband and differential are sometimes reversed in their definitions depending upon whoever wrote the manual. My last Carrier stat install had deadband as the on/off swing and differential as the difference between heat and cool settings. But this is all beside the point. The on/off swing setting, regardless of what this is called on your stat, is the only t-stat setting that could cause what you are seeing,as settings go. A fault with the t-stat is a highly remote possibility, but you may have gotten that one of those 1 out of umteen faulty ones. But like I said, this is going to be impossible to diagnose over the intenet because there are too many parameters on your particular unit that require manual testing and/or checking. Good luck resolving this, and remember that you are free to contact Carrier yourself, they won't mind, and will even be happy to take your calls and or e-mails.

hvacrmedic

[googlemail2003]

Well, looks like we solved the problem. I put a thermometer on top of the thermostat. I kept track of when the temps changed and noticed it happened AFTER the furnace came on and shut off. That made me realize that the cold and warm air was getting to the thermostat from somplace other that the area around it. I looked around and found two heat registers that were closed in the dining room, which meant that area was colder than the living room. We almost never use the dining room but it's closer to the thermostat than the living room is. It was screwing up the heat. When I opened them up fully things improved dramatically.

We are thinking about getting a remote room sensor so that the thermostat can react to the temp in the living room and not in the dining room. Do you know if the remote sensor can be easily deactivated so the furnace and/or air conditioner responds to the thermostat sensor if we want it to?

Anyway, things are much better. Thanks all for your help.