"The salesman also states he can only give me 48 hours to decide because new systems will be coming in shortly at a 10 to 20% increase." - Nothing like high-pressure sales tactics to force a quick decision. I would't buy from that chump. The Trane price sounds very reasonable. I was quoted about the same price last year for a 3-ton XL14i in Baltimore. You need the model numbers of both the condenser (outside unit) and air handler. Condenser will be something like 2TWX... and air handler 2TEE... Post the model numbers and I will confirm efficiency ratings (SEER/EER/HSPF) as well as cooling/heating capacity. I agree with Tiger about the 10 year PARTS AND LABOR warranty to protect yourself. It sounds like you have ductwork issues that need to be addressed. Ductwork is critical for a good install. Poor ductwork = poor air flow = poor system, regardless of heat pump manufacturer. Best to you.

You do not "need" a variable speed air handler. I have one. They are a premium item that is good at reducing humidity, properly configured, while providing superior comfort control. They are expensive, and should be matched to an appropriate heat pump and thermostat in order to get the most out of the system. But you don't "need" one. A standard air handler should work properly in any normal situation. What you really need is a tech that can properly diagnose your problem and communicate it to you in an understandable manner.

I am in agreement with everyone, the unit is old but as stated, was purchased by TRANE. However, the relays and other supporting parts are readily available. If I'm correct, I think Tigerdunes was pointing in the right direction. If you are not familiar with heating with heat pumps, then the air coming from the vents while in the heat pump mode alone, would feel cool to you. One thing you mentioned was that while it was in the heat pump mode, you did not measure voltage to the element. That would be normal. When the unit calls for AUX or Emerg. heat, then you would get a voltage to the heaters. Here's what I think is happening....the reversing valve is stuck...it was common on the older units. The unit stays in the cooling mode and when the first bank of heaters comes on, the cool air overcomes the full effect of the heater. Check the air coming from the outside unit. If it is warm and that will confirm the possibility of a stuck reversing valve. As mentioned also by Tigerdunes, replacing a reversing valve is expensive and given the age of your unit, whole replacement of the unit would be a better choice. Now a professional should be called however, I'll give you one thing you can try, if indeed it is still in the A/C mode. You can force the valve to slide into the heat mode by doing this.....disconnect the blower at the condenser. Turn the unit on in the heat pump mode and let it run....Given your temperatures, the condenser will slowly build pressure on one side of the valve as the pressure drops on the other side. You'll know you are getting close when you hear the compressor staring to load up. You'll suddenly hear a whoosh and the reversing valve has now reversed. Let it run for about a minute to make sure it has fully reversed. Shut the unit downand hook the fan back up. When the unit goes into the defrost mode, the valve may work and the unit defrosts but may not switch back to heat mode (sometimes they do, sometimes they don't.) If that's the case, you have to do it all over. This suggestion is just to get you some heat until you get someone out.

I am confused as to what you currently have. You mentioned you an electric furnace and a heat pump. Then you talk about moving to propane instead of a heat pump. In your first post you said your current heat pump is 2 tons, but in a latter post you said it is 2.5 tons. It is hard to believe that you can increase your heat pump to 4 tons without increasing the main supply and return. Perhaps your duct work was originally the proper size, but someone install an undersized heat pump. If you want some advice, then please describe the size of your house, and exactly how you heat your house now. Heat pumps are sized by cooling loads and not heating. The winter design temperature for Columbus is 6F degrees, but it can drop to much lower temperatures. You need a properly sized heat pump with a back up heat source. That heat source could be electric heat strips or a propane furnace. If you post your electric rate and the price you pay for propane, a calculation can be done to compare the heating costs.