In this situation we have a customer who has called for service on their gas furnace, and the description of the problem is “no heat at all.” The customer also reports that this is the first time they’ve had to call for service on their 10-year-old unit.

In this troubleshooting situation, the equipment you’re servicing is a 240-volt, single-phase split system in a small office, and the customer’s complaint is that the system is blowing warm air.

In this troubleshooting situation you have inherited a service problem that goes back to last year’s cooling season… residential HVAC equipment that’s seven years old with a lot of history, and repeated trips in response to complaints that this split system that employs a horizontal, attic-installed gas furnace “just won’t keep the home comfortable.”

This month’s troubleshooting situation involves an under-counter refrigeration unit in a commercial application. The first technician explained to the customer that the compressor needed to be replaced. After that technician left, the customer called the office to request a second opinion.

In this month’s troubleshooting situation, our customer has called to say that the older package unit that heats and cools his office is managing to warm up the area, but then seems to cool down too much before providing heat again. When you arrive, the first thing you note is that the indoor blower motor is operating, and you check the fan switch setting on the thermostat.

This troubleshooting situation is a look ahead to the upcoming cooling season. Our customer has called to say that their heat pump “isn’t cooling at all,” and while the outdoor temperature is only in the mid 80’s, it’s quite uncomfortable in the house. You find that the underlying reason is that the compressor and outdoor fan motor aren’t operating.

When the customer calls for service, he tells you that when things got very cold in the house, he disconnected the power supply to the unit, and then, after turning the 120-volt service switch back on, the operation seemed normal and the house got warm “for a day or so.” But the failure repeated.

In this troubleshooting situation, we have a customer who has called to say that their 12,000 Btu through-the-wall unit is “blowing cool air even though it’s set for heat.” The unit is a heat pump with a three-speed motor. It operates on 240 vac.

Your role in this month’s troubleshooting situation is as the follow-up technician on a problem that was made worse by the technician who preceded you. When the restaurant manager originally called for service, the complaint was that their small walk-in cooler “wasn’t keeping as cool as usual.” Now it’s “hardly cooling at all.”

This time around our problem centers on a split-system air conditioner. The condensing unit is 240-volt, single-phase, and the indoor air handler (which our customer is able to tell us is “blowing warm air”) consists of a standard gas furnace and an A-coil housed above the furnace plenum.