I had use Air Tron in the past and had a warranty with them. Called recently for a PM and they are now Air Rescue. 3 weeks after PM main unit developed a leak that they said is common with Lennox system. Cost me an additional $650 stating that coolant is not covered. Manager would not return the techs phone calls and has not returned my phone calls. In my opinion, buyer beware. I will not use again and certainly would not recommend.