As usual, Air Con is the best. The tech (David) was prompt, courteous, knowledgeable and very helpful. David pointed out that we were missing a gas line drain that should be on our system to prevent costly damage to the smart valve in our furnace. David gave us a quote and will return next week to install. This drain will also bring our heating system to code. It's another example of how "pro-active" Air Con is to help customers like myself from costly "reactive" actions later on down the road.