I bought a brand new central a/c and gas furnace about 2 years, I never have to use the heater until this winter. My problem is when I tried to turn on the heater, I did see the electronice ignition comes light but after few seconds is shutting off. I noticed a blinking red light on the control pannel, I verified what that means in the error codes and is stating error code #4"Ground error" what that means can I repair the problem myself? Or I have to call for service, also the HVAC tech who intalled my a/c and furnace also installed a new thermostat. He was a subcontractor so I can't find him to repair what he installed any advace, please help my kids are freezing.