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.

2 quick things you can check. Is the line voltage wired correct? Sometimes a netural and ground get crossed by an untrained service tech. Next see if you have a green wire coming from the board to a ground source. Polarity is very important to the board, so if the netural and ground are crossed somewhere it's going to be the wrong polarity. The board has to have a good ground to operate correctly. It may be just tightening a loose ground wire.