In the summer of 2011 my wife and I decided to find a way to heat our home more economically. LP gas in our area was at about $2.00 per gallon and our yearly LP gas bill was $2,500,00-$3,000.00 per heating season. We contacted Muller Heating and Mechanical to look into a Geothermal System. Muller was one of four contractors we consulted. Jim Muller told us that we would be able to heat and cool our home for $1,000.00-$1,200.00 per year if we installed his system. Of course we were excited about this, we would be cutting our expenses in half! Jim Muller told us he had installed 5 or 6 of these systems so we were confident in hiring him to go ahead with a system for us. Mulller installed our system at the end of August, 2011. Muller installed a Geothermal Heat Pump, a new LP gas furnace and a new electric water heater, which is connected to the Geothermal Heat Pump. We paid Jim Muller $15,000.00 for this system. That is when our problems began. From day one after the install, the system didn't work correctly. The Geothermal Heat Pump was supposed to be our main heating and cooling source, with the LP furnace automatically kicking in and performing as the back-up heating source if something would happen that the heat pump failed. It didn't work this way, neither of the systems worked correctly. As of June 13th, 2013, Jim Muller or someone from his business, and at least 2 other contractors (who accompanied Jim) have been to our home 22 times attempting to get the system working properly. Our home is approximately 60 miles one way from Muller's place of business. We have come home at least 5 times during the winter months of 2011 and 2012 to find our house at temperatures in the 50's and neither the Geothermal heat pump or the LP gas furnace were working! Our home is in northern Wisconsin, it gets very cold here. We were afraid to leave home for any extended period, we surely could not go anywhere overnight. Attention to details seem to be most of the problem, the wiring between the Geothermal Heat Pump and the LP furnace was wrong, and the installer's internal programming of the thermostat was incorrect. There were also little things that a competent contractor should know that were overlooked. One such thing was the drain line from the LP furnace to the condensate pump was not vented. This will cause the LP furnace to shut down, which it did. It took Muller two heating seasons to figure this one out! Another was the thermostat "differential" was set wrong, this caused the system to run in Stage 2 mode at all times. The system is supposed to start up and run in Stage 1 mode and switch to Stage 2 mode if conditions warrent. This also took Muller nearly 2 years to resolve! Besides these mechanical and wiring issues, Jim Muller's workmanship is very poor to say the least. When his joints in the new ducting didn't fit right, he covered it up with duct tape! Jim Muller also made a new plenum above the LP furnace, it didn't fit so Muller duct taped this connection! This was done by Jim Muller himself! The solder joints in the new copper piping also look very unprofessional. The majority of our electrical bills from Nov.-March, through both winters of 2011 and 2012 are over $250.00 per month, one as high as $479.00. This is considerable higher (let's say twice) than before the system was installed. We are spending about the same for our heating now as we were with our previous system, which was a 3 year old Payne (Carrier) LP gas furnace. We spent $15,000.00 to do this!? Jim Muller's only response to this was that "he didn't think they would be that high!" The system seems to be working OK now when we are using it in the "Cooling" mode, we will find out this fall if it will work in the "Heat" mode. This has gone on now for 2 years, we have been very patient with Jim Muller. It is obvious that he doesn't know what he is doing. To say the least, we are very disappointed with our system and feel we have been mislead and lied to by Jim Muller. I would NOT recommend anyone contract with him.