I had a Goodman 2 1/2 ton 13 SEER heat pump installed April 2004 by a well respected and licensed contractor. My indoor equipment was replaced with a 17 kw Mortex air handler and coil; the Washington State Dept. of Labor and Industries, responsible for manufactured homes/permits, would not allow me to install a Goodman air handler/coil because it has not been tested in mobile homes. The new thermostat is a non-programmable Carrier model (installed last month replacing a Totaline thermostat which was off by 5 degrees). All this new euqipment replaced 16 - 20 year old Coleman equipment (9 SEER heat pump). I expected to use the same or less electricity with the new energy efficient equipment.
Here is my problem: My energy usage/utility bills increased immediately. Even when in cooling only mode during summer, I used 12% - 59% more electricity. During the past three winter months (relatively mild, temps mostly in the 40's, nights in the 30’s), I’ve used up to 67% more electricity with a lower temperature setting (66 degrees for 18 - 20 hours/day, up to 67 for 4 - 6 hours/day; actual temperature in the house 64.1 - 65.3). These percentages are based on my utility bills covering the last three years before the new equipment was installed and averaging every month for the three year period.
The installer claims to have checked the equipment and pronouced it running; the utility company tested the meter and it is not malfunctioning; Goodman argued that their energy savings claims are based on tests involving all Goodman equipment.
What can cause such an excessive increase in electricity usage even though I’ve lowered the temperature in my house (and I am cold and uncomfortable)?
Would the fact that I have other manufacturer’s equipment installed indoors make the Goodman heat pump run less efficiently?
I've made a diagram of the wiring on the new Carrier thermostat and compared it to the wiring diagrams of the Goodman and Carrier installation manuals; my wiring does not match any shown in either.
Would really appreciate some ideas or suggestions. Thank you.