I have some questions that I hope someone here can give me some direction on (not technical DIY stuff).

In Aug 02 I had my 6 year old Goodman unit replaced with the following Trane units:

4TWX4042a XL14i heat pump, 3.5 ton
4TEE3F49a V/S Air Handler, 4 ton horiz.
BAYHTR1415BRKA 15KW Aux. Heat
T8011R Honeywell Thermostat
10 year ext. warr.

My problem is that my kwh usage during the winter months is excessive (for Texas, I live in Dallas).

At first, it seemed in line (but not better) than the Goodman. Jan-03 was 2050 kwh, Feb-03 was 2257 kwh, Mar-03 was 1675 kwh. Aug-03 was 2397 when avg temp is 100 in Dallas.

Then, Jan-04 we got hit with 3522 kwh. Dec-04 was 2040 kwh, and Feb-04 was 3085 kwh.

I called the installer, and he came out at the end of Jan-04. The work order states he

"tested the aux. heat package - 15 KW ok, (64 amps) - checked freon level at heat pump, ok - all amp draw and Freon levels ok (normal) no other problems can be found - recommend installing hot water tank timer"

At the end of Mar-04, I called him back because the consumption was still high. He checked freon and said it was several pounds low. He couldn't figure out why I was concerned until he realzed that he had been just out and said it was okay. He put some 410a into the system, and said he would recheck when he came back out to clean in a couple months (which he canceled and I couldn't get another time set up). He didn't charge me for the trip and didn't leave any paperwork.

Things were good all during the mild summer, now have the high Jan and Feb kwh being consumed in the 3000's again.

Is this being caused by the aux heat coming on too much because of leaking freon? Or an incorrect install/setup of the aux. heat? Before I have him come back, what should I press him to check?

The house is only about 1500 sq ft, and our electrical bills have been on average higher than any of our neighbors with the same or larger homes. I've installed a new water heater with built in timer last year. I am in process of removing the blown in insulation (supposedly R-30 but it has many thin spots) with multi-layers of batts at R-55. I've been sealing all my ducts and registers. I really want my bills to come down.

How much should a system leak in a year? I don't think any, but the installer argues otherwise. The only part the didn't replace was the vertical line in the wall. He was pretty good on the install but his follow ups (and keeping appointments) has been kinda thin. My wife wants him off the contract but I'm more of the mind 'you installed it, you fix it'.

What can be wrong, and what should I have him check?