Are you in need of air conditioning and heating parts?
If your central air system is not working then you may want to contact one of the HVAC dealers in your area. You should be able to find all your repair parts and a certified distributor warehouse. They will have a wide variety of both new and used heating and air parts for you to choose from. The benefit of going with a new part is that it will most likely be under warranty to where a used part will not be.
Now, you need to visit a few AC and heat pump supply houses before you make your decision on where to purchase your part from. Some of these warehouses have been known to rip people off. So you really need to check the prices on each distributor that you go and see and compare them to all of the others alike. Once you feel as if you have found the best and most trusted supplier you can then make your purchase.