I have a mobile home that has a central a/c and heating unit....the last few months my electric bill is sky high....almost $300 each month....i suspect the problem being the central unit.....when it reaches temperature on the thermostat it will quit heating but the fan stays on until i have to manually turn it off...to do this i usually have to turn it off a few times before it actually works...

any ideas to what is causing this?..thermostat bad? fan switch bad?

my other problem is ..my house gets heated or cooled unevenly....the back portion of the home gets hot/cold quick.....while the other end of the house doesnt cool/heat properly......the air flow coming through the floor vents is much better at the back end which is where the unit is located.......any ideas on this...how to fix it?

any help would be appreciated.. thanks!