Bob and Tim have just repaired a leak on a 10-ton commercial air conditioning system and are ready to charge the unit. The system has a thermostatic expansion valve (TXV) for the evaporator.
Bob and Tim are at lunch after tuning up an oil burner. When they arrived at the job the home was cold and the oil burner was burning erratically if burning at all. They gave the system a tune-up, started the furnace, and decided to take a lunch break while the furnace heated the house. Then they were going back to do a combustion check on the furnace to make sure that it was set up for the best combustion.
Bob and Tim have arrived at a customer’s house that uses fuel oil for heat. This is a “no heat” call — the customer called first thing this morning and said that the oil furnace was not coming on, and the house was cold. When they arrived, they talked to the customer, and the customer said that he had made several tries to get the furnace to operate but with no luck.
Bob and Tim have responded to a service request where the customer is explaining that their heat pump is running all the time. The indicator light on their thermostat is lit most of the time, indicating the strip heat is on as well. The weather is cold today but has been warm some days and cold some days. It’s a very unusual heating season.
Bob and Tim are on a service call on a really cold and blustery day. The temperature is 27°F, the wind is blowing, and it’s snowing and sleeting. When the customer called, she said that their home is getting cool inside, and their heat pump is running all the time with the temperature dropping inside the house. They arrived at the front door, talked to the homeowner, and decided to look around. They went to the closet where the indoor unit for the heat pump was located and determined that the heat pump itself was not running, only the fan and strip heat.
Bob and Tim have had a big day at work — it’s 3:30 in the afternoon, and they are done for the day. They’re having coffee at a local restaurant, talking about their careers when Tim asked a question, “What is a ton of refrigeration, and why is it called a ton?”
Bob and Tim were on their way to a no heating call. When they arrived, they looked at the house and saw that it had a package unit. They talked to the housewife and she told them that the unit stopped running sometime in the middle of the night last night.
Bob and Tim were checking a customer's air conditioner and initially thought the unit must be out of refrigerant or very low on refrigerant. But after adding some refrigerant, the suction pressure did not rise at all. Bob then determined they should look for restrictions in the liquid line or the suction line.
Bob and Tim were at a customer’s house doing a seasonal checkup on a condensing gas furnace. This was routine service carried out every year on this customer’s equipment per a service agreement. But when they tried to operate the furnace, the burner would not light.
A customer was explaining what was going on with his air conditioning system. His old system had stopped working and he was told that it needed to be replaced. Money was tight and a cousin had a system removed from a rental property. So they replaced the original 3-ton package unit with a 4-ton package unit.
