Arrived on site for no heat call. Assisted homeowner in operating Trane thermostat for other unit that was not having issues. Homeowner stated thermostat had turned off and was unresponsive. Upon inspecting the thermostat I found it was powered on and seem to be cooling. I then tested the drain line with a gallon of water and found no blockage. Upon taking a temperature split I noticed I was only getting about a 10° difference. And then went outside and verified refrigerant pressures and found the low side testing around 60 to 70 psi and high side around 200. I removed the very dirty filter from the unit and instantly measured a 20° split upon checking pressures. I found 110 on the low side and around 200 on the high side. I then tested zone one damper for the upstairs and zone two for the downstairs and found no issues. Advised homeowner to replace filters every month. Unit in good working order upon departure.
