In this month’s troubleshooting situation your customer is requesting a second opinion on a proposed repair to their air-source heat pump. The homeowner originally called for service when they noticed that the house wasn’t cooling down as they would like.
A new customer called and wanted their commercial unit serviced. The customer was a retail store and the manager seemed to think that the unit was not performing up to standard. The unit would run most of the time, even in mild weather, and did not seem to cool the store as well as it should.
Ensuring energy efficiency, cost effectiveness, and comfort
June 8, 2015
Gwinnett County Public Schools (GCPS), located in the Atlanta metro area, is the largest school system in Georgia. The school district runs a full preventive maintenance program on most of its mechanical equipment. And it continues to add new preventive maintenance job plans for pieces of equipment that didn’t have one before.
Bob and Tim were at a no cooling call, the first of the year. They turned the thermostat to cooling and put it on a low setting so the heat pump would come on and stay on. They went to the outdoor unit and felt the leaving air and the piping and Tim said, “The unit is running in the heating mode. I wonder what is going on?”
In this troubleshooting situation a technician has responded to a complaint of “not cooling” on a six-year-old R-410A split system that employs an upflow gas furnace indoor air handler and a condensing unit that sits on the ground, and there is less than 20 feet of connecting tubing.
Bob and Tim were on their way to a service call at a store that has a frozen heat pump outdoor unit. It is late in the season and the customer called and said, “Our outdoor unit is frozen solid with ice.” After they arrived and talked to the owner, Bob said, “Let’s put the unit through a forced defrost.”
The most important approach to an ice machine repair to keep in mind is to remember that it is part of the HVAC family. What this means is that most ice machines stop working due to being dirty, either the air or water aspect part of the machine.
Bob and Tim were on their way to a no heat call for a gas furnace. Tim asked, “What do you think we need to look out for on this call?” Bob said, “It could be any number of things. We will start by talking to the homeowner and see what she knows.”
This troubleshooting situation centers around an older 3-ton split comfort cooling system, and the customer is calling because their home is “just not comfortable.” The homeowner also tells the dispatcher that while the unit is operating and air is coming out of the registers, the temperature in the house is too warm.
With the heating season in full force, it is a good time to review best practices in heating troubleshooting. This article covers boilers. The following information is a summarized section from HVAC Troubleshooting, a guide book published by BSRIA, a test, instruments, research, and consultancy organization headquartered in the UK.