We had two vents in our new house that weren’t pushing out heat at all. Controlling Systems was great and said if they couldn’t diagnose the problem because ducts were in the wall or something, they wouldn’t charge the $ 49 diagnostic charge. They sent someone out within 2 days of my call. He was very nice and helpful. The problem was simply the previous owner had used the wrong type of filter in the furnace. He had the right one in his car and voila, fixed. He did warn me of the vents not being in great spots come summer, and we talked about additional a/c options even though we have central air. He was very helpful and informative, though I do wish he had been a bit more responsive to my statements about waiting to see how it is in the summer and save a little just in case. Then again, I know upselling is necessary, and I’m sure we do need the product!