When it comes to HVAC heating units they include varieties which are fueled by electricity, natural gas, heating oil and propane. Similarly, they include different types of heating unit like the forced air, the convection and the radiation. It is true that these systems can be highly complicated and might require technical intervention as well. However, there are certain things which if followed closely can save you a lot of unwanted expenses in the repair and maintenance of your heating units. The common types of heating units include forced air, radiant, hot water baseboard, steam radiant and geothermal. Here it must be noted that in order to carry out the simple repairs of these services it is important that one understands the working of the unit.