Bob and Tim had just arrived at the house of a new customer who explained that the air conditioning system was not working. The homeowner said that they had just had a warm day and the air conditioning system did not come on when they tried to cool the house down yesterday.
A thermostatic expansion valve (TXV) is designed to maintain a specific amount of superheat at the outlet of the evaporator. If the superheat value is too high or too low, the TXV may be the cause. However, before deciding the TXV is defective, all other system causes must first be investigated and ruled out.
Bob and Tim had just finished a routine service call on a house with a gas furnace for the heating system. They were talking to the housewife when she asked: “Our house is very dry in the winter time, and the humidity must be very low. How can we put a system in this house to keep the whole house at a higher humidity level?”
In this troubleshooting situation, the equipment is a split system that’s approximately five years old, consisting of a gas furnace to provide heat in the winter, and a condensing unit and “A” coil to provide summer cooling. There are actually three questions to answer in this problem.
Bob and Tim were driving to a service call where the customer’s complaint was that her home’s windows were sweating excessively. Tim asked, “What could be some of the reasons that a customer’s windows would be sweating?”
The correct placement and installation of the thermostatic expansion valve (TXV) sensing bulb is important to its overall performance and reliability. An incorrectly installed or placed sensing bulb can lead to several different types of system problems. Here are some general installation concerns and tips to follow when installing a TXV.
It was the first really cold day of the winter and Bob and Tim were on the way to a service call on an oil burner. The customer said that they had no heat. It was about 15°F outside so they were in a rush to get there.
In this troubleshooting situation, you are responding to a customer’s complaint about their heat pump, and you’re not the first technician called in to solve this problem of “not keeping the home comfortable and running a lot.”
Bob and Tim were at a retail store and were preparing to do a routine service call on a 5-ton heat pump. It was a fall day with a temperature of about 50°F when they turned the heat pump on. After doing a visual inspection at the air handler, they moved to the roof to give the outdoor unit a visual inspection.