Bob and Tim were on their way to a residence where the occupants said their unit runs all day long, but the space temperature rises to 82°F while the thermostat is set at 75°. The unit shuts off during the night and the temperature inside is 75° in the morning, but during the day it rises.
In this month’s troubleshooting problem, you have been called by a colleague who is relatively new to HVACR to assist in repairing a split system in a manufactured home. The original diagnosis regarding this unit that is sitting dead was that the PCB 3-amp fuse was blown, and when it was replaced, the new fuse also failed.
Bob and Tim have gone back to the job with the grounded compressor. They changed the compressor yesterday and ran the unit for a few minutes, then shut the system down, leaving the crankcase heat on so they could start it up later. They now want to determine why the compressor burned.
For over 50 years, evaporative cooling products have been manufactured from hot-dip galvanized steel. Life expectancy of these units, when properly installed and maintained, has been excellent. In recent years, however, there have been reports of “white rust.” The critical fact that needs to be recognized is that white rust is preventable.
Bob and Tim were on their way to a no cooling call at a commercial building. When they arrived, they talked to the building manager and checked the thermostat. It was set at 72°F but the thermometer was reading 78°. Tim said, “The fan is running, so there is control voltage and the thermostat seems to be calling for cooling.”
In this month’s troubleshooting situation, our customer’s description of the problem is “not cooling” and “blowing warm air,” and the equipment that is supposed to keep this residence comfortable is a split system that has been in service for 16 years.
Bob and Tim were just finishing a service contract call when they were contacted by the dispatcher about a no cooling call at a new installation at a small retail store. The weather was unusually warm for this time of the year.
During my 50 years in the HVAC trade, I have found that most technicians do not spend time learning about the compressor and the a/c system as much as they should. In their defense, they are simply too busy to take the time once they are out of school.
Bob and Tim have been sent on a routine service contract call to a new customer. The system is a gas furnace with central air conditioning. After changing the filter and oiling the fan motor, Tim went to the thermostat and caused the furnace to come on and they were looking at the burner when Tim said, “That gas flame doesn’t look right.”
In this month’s troubleshooting situation, we have a customer who has called to say that their condominium has no heat. The particular equipment in this case is a thru-the-wall package unit that provides cooling in the summer and employs a natural gas system to heat the building in the winter.