I am in the process of switching from an Oil fired boiler to a geothermal heat pump. My system has a tekmar 153 and a Nix control box. Is there an easy way to reprogram or rewire these units to run with a geothermal heat pump. Essentially I need to change my nix pump box to turn my circulating pump on when ever a thermostat turns on. and the tekmar basically to keep my mixing valve open. The geothermal unit should just run about 120 through an 80 gallon buffer tank.

If you are asking if you can use a geothermal heat pump to heat hot water for use in water baseboard unit like most oil fired boilers are used for, the short answer is no. A geo isn't going to heat the water hot enough.