Everything else outside sounds like it's running... the unit doesn't shut off. When it's blowing the warm air and the fan stops, the unit makes a loud buzzing sound and you can feel it putting off hot heat. As soon as the fan starts back up the sound goes away and it pushes out cold air. I haven't taken anything apart on the outdoor unit yet. But I took the panel off the indoor unit and it looks like new on the inside. I'll look at the outdoor unit more in depth tomorrow. Are those two things something that I can replace and if so, how can I tell which part may be bad?

Some of these comments are reiterated again and again. I am a retired HVAC/R professional with over 40 years experience. There is no cut and dried answer to most of these questions. Most of the answers are mostly correct in that you need to seal your ductwork, insulate it if it is in non-conditioned space (attic/crawl space), and the ductwork needs to be laid out correctly to supply AND return the correct amount of cfm to each room. After that, NO air conditioning technician in the world can correctly diagnose an air conditioner's problem unless several criteria are met. First and foremost, BOTH the condenser coil and the evaporator must be clean and the furnace (air handler) filter must be clean and not restricting flow. If you call a company out to your house and the technician comes up to your house with his gauges and refrigerant tank FIRST THING and immediately hooks the gauges up and starts putting refrigerant in, my advice is not to call that particular company back again. The coils MUST be clean before you can even begin to decide that the system is under or overcharged. Next you must make sure that you are moving the correct amount of cfm for the size air conditioner you have. 400 cfm/ton is the nominal amount for air conditioning. NOT ONE person has mentioned how important this is. On MANY occasions, I have seen brand new equipment installed and no one can figure out why it won't work! With brand new equipment, we know the coils are clean so that is not the problem. Let's say we have a house that is 2400 square feet and a new furnace and air conditioner are installed. It's a 105,000 btu furnace and a 3 ton unit. The homeowner complains that their old furnace and a/c (same size) worked fine until they had to have it replaced. Technician after technician comes out.....they hook up their gauges and add and remove refrigerant and can't figure out what the problem is. The a/c runs almost all the time and the pressures are correct but the relative humidity in the house is REALLY high and they can't figure it out. Some technicians recommend a whole house dehumidifier as a fix. C'mon people, let's not put a bandaid on this problem. What most technicians tend to forget with an installation of new equipment is that the new furnace doesn't KNOW what size air conditioner it is being mated with! The new furnace can typically be mated with (and has the blower assembly to work with) anywhere from a 3 ton to a 5 ton unit. These furnaces will have as many as 6 different speeds for the drive motor. A 5 speed motor is more typical but the factory sends these furnaces out USUALLY with the lowest speed set up for heat and the highest speed set up for cool. This means with the 3 ton unit (which needs 1200 cfm delivered), on the highest motor tap speed from the factory, the furnace is delivering 2000 cfm or more! Moving 2000 or more cfm through a 3 ton evaporator will result in a "delta T" of 10 degrees or less which explains the unit running almost continuously and the high relative humidity in the house. These technicians need to remember that they need to look in the installation manual to find the right motor tap speed to utilize with the size a/c being mated to the furnace. With the advent of the 95+ % furnaces, we are seeing ECM motors being deployed in the furnaces. These have no speed taps, but instead have a motor that is in essense a variable speed motor. The technician still needs to consult the installation manual as the motherboard in the furnace will have dip switches to set the motor drive unit to supply the desired cfm. Now, some "rules of thumb." IF your coils are clean, IF your furnace filter is not clogged up with dirt and providing a restriction, IF you are moving the correct amount of cfm for your size a/c, IF the superheat is correct and IF the subcooling is also correct, you should get a delta T of between 17-22 degrees and your supply temperature should be between 51-55 after the unit has run for 10 minutes or longer.

I'm not too familiar with this new air handler from Trane. I believe they did away with dipswitches and went to an LCD-type control on the board. So there are settings to scroll through. Not sure if they left the installation instructions, so might have to rely on a competent tech. Condensation is normal -- too much could indicate airflow too low, or just very humid weather -- hard to judge from here whether it was a normal amount given the conditions. As TD said above, the noise is either from undersized ductwork, improper air handler speed settings, or both. If it's that noisy, the company should come back out. If they changed the airflow, they should have checked the refrigerant charge. What does the ticket say?

Trane XL 20i Trane Variable Speed Handler 4TEE3C08A1000A 15 kw Heatstrip BAYHTR1415BRKC Honeywell HZ432 4 Zone Control When the outside unit's fan shuts off and it's still making noise, (something is still on; I guess the compressors, defrosting maybe?) the HZ432 indicates Heat 1 and 2, and cold air comes out. The outside fan starts back up and it heats up. Also I'm unable to notice any heat increase when Aux heat comes on indicated by the stat. How many of the 3 strips should be on during Aux Heat? I suspect some or all of the heatstrips are not working. My understanding of the HZ432 4 zone control: Heat1 = 1 Compressor Heat2 = 2 Compressors Heat3 = ? I've never seen this on. What would or should this be? EM Heat = Can I push this button when the heat pump is on or should I turn the system off first. My understanding is the outside unit does not run during EM Heat. How many of the strips come on during EM Heat? Thanks for your help.