Hi,I am really hoping to find someone to help me if possible. I have a one year old carrier infinity 4ton 17seer condenser and a 5ton variable speed air handler. I has worked fine but now i am getting a SYSTEM MALFUNCTION on the thermistat. When this message appears the air handler continues to blow and only the fan on the condenser continues to run but NOT the compressor so it is not cooling. At times it begins cooling again but then later stops cooling and shows the same malfunstion message. I have called out carrier tech and they have no clue so far. They have checked the contactors also and they look good. The error code is 73 on the air handler and the condenser error lights. The error in the menu of the thermistat read: contactors shorted and compressor voltage standby. Is this a mystery? Thanks.

That light being during cooling means that something is pulling too much current. Check the relay in the outside unit (warning high voltage) and if you have a condensate pump attached to remove water, make sure it is working.
http://www.hvac.amickracing.com/Furnace%20Info/Variable-Speed%202-Stage%20troubleshooting.pdf

Carrier Infinity system is a variable speed unit that will just slow down as it approaches set point. Unless it overshoots the set temperature (you have it set on 72 and the temperature keeps rising above 72) this just sounds like normal operation.

does your burner flame up and then go put two or three times if so
all you have to do is take out the burner and clean all the soot out of it and then wipe off the sensor

Hi,

Here is a tip about troubleshooting your air conditioner...
There are many things that can cause your air conditioner not to cool...

AirConditioner Trouble - Review the Possibilities

heatman101

Pretty sure the 5C = 5 tons.The model # will always help with size...3/4 hp is on 4ton & 5ton

Hi,
No, that will not hurt your new system as the old lines were vacuumed down and all of the R-22 removed...
You will be fine and it will not void the warranty...

heatman101

Hi,
It's possible that you have condensation built up in your carburator. Tiny droplets can deny gas to the cylinders. Since you put in new gas and I assume you are getting spark, drop the bowl on the carburator and check for this culprit. Could be a quick fix.
Hope this helps... Good luck!

Either its not drainning mositure properly or low air flow across the "A" coils- caused by dirty filter .

if your air handler and ductwork are sweating, this tells me that the unit is operating too cold. The slower the airflow, the colder the temp. Your infinity unit is a wonderful machine! But I've seen many of these units that horizontal leak water due to airflow issues. The air handler(inside unit) has a true "variable speed" blower motor. Where we used to have low, med., high speed, now an 1100 rpm motor will have 1100 speeds(so to speak). Now after installation, the company should have sent the technician to set the system up by checking a TESP, total external static pressure. This info is located on the air handlers info on the front of the unit(sticker on panel). This verifies that the airflow is adequate and proper for your house and ductwork. If this is not right then blower motor damage may occur. Also, if you can imagine a cold can sitting on the table. If the temp in the air is warm and moist the cold can is cooler that the air it is sitting in. The can will sweat and a puddle will form on your table. Now, your air handler is running too cold, probably due to low air flow. Its sitting in a warm(er) moist environment, and sweats. It's all insulated but this won't matter due to infiltration of warm air through the insulation. Most people don't understand why too cold is a problem in cooling but this is one problem we have. And also, this unit may be leaking water from the condensate pan. I've had issues with this style. If it's not draining properly, the pan holds water and that water is pushed out of the pan by the blower. If the unit is not level, or down hill just a bit, towards the drain outlet, it will hold more water in the pan than its designed to hold. It also has a zoned damper? These zoned contrlloer/damper control modules can be installed anywhere, not just a closet. It would help if it's in a controlled environment, but not necessary if the machine is set up properly. I'm 99% certain you have an airflow issue! Get a second, third, fourth opinion. It may/will take more than 1 trip to fix this. Carrier corp. has dealers that sell/install Carrier machines. These companies have experience (ask them up front) with the infinity. And also have Carrier tech support. Ask for a TESP check before you schedule a service call. And any qualified tech won't mind explaining this process as you look over their shoulder as the work. You'll also been to get the duct reinsulated. I would contact your installer and ask them to rectify this issue, at their cost. Your contract with them should state a warranty, and also a "time subject for repair" if problems arise. If you are not satisfied with their answer, call your local/state license authorities. City inspection may/should work if you're inside city limits. Carrier also has field techs! But cost about twice as much as you're used to. Hope this helps!

Only that you might be right about the clogged drain; if you can reach the drain end of the hose, you might try covering it and blowing backward into it to see if it is in fact clogged.
Our setup has the drain located with easy access and the initial pipe is open and centered over a larger fitting so the condensate can drip freely into it.

Good luck-