Bob and Tim were on their way to a no cooling call at a commercial building location. This is a large manufacturing plant that has a number of installations. They arrive and talk to the maintenance man and he tells them which unit it is and goes with them to the area that the unit serves. It is a large room served by a 20-ton split system.

In this month’s troubleshooting problem we have a homeowner who has attempted to repair his own equipment, and he has replaced two components. The original symptom of the split system sitting dead still exists.

Bob and Tim had left this residence a few days ago when they discovered that the four-way valve on the home’s heat pump was stuck in the cooling mode. They tried several things to get the valve to do its normal changeover to the heating mode and couldn’t get it to function. The valve would need to be replaced.

It’s well recognized that your car or truck needs regular maintenance. HVAC contractors and technicians likewise emphasize to their residential customers that their HVAC system needs a regular tune-up to keep the unit up and running and provide optimum performance. Here are 15 essentials of a residential HVAC tune-up.

Bob and Tim were on their way to a service contract routine procedure when the dispatcher called and asked them to go to a residence that had no heat and had a very sick family member. They needed heat as quickly as possible.

In this month’s troubleshooting situation, we’re taking you to a school, but not to the equipment room of the main building. Instead, it’s a modular classroom (similar to a double-wide manufactured home) that is brand new, and employs a heating/cooling unit that mounts on one end of the building. 

Bob and Tim were on their way to a “low heat” call at a residence when the dispatcher called them back and told them that the homeowner had called and explained that the furnace was hot, but the home was cold. The dispatcher had told the owner to shut the furnace off until Bob and Tim arrived. 

What factors prevent fans from not performing as specified? There are numerous reasons why fans may fail to perform as specified, but first it is important to understand what defines acceptable performance.

Bob and Tim arrived at their fifth service call of the day. They were both wet from servicing a heat pump outdoor unit in the snow. This was a no heat call for a gas furnace. The weather was cold and there was no heat at all in the house. 

In this troubleshooting problem, the customer’s general definition of the situation gets more specific when you arrive at the site and discover that the reason there is no heat is because although the burners ignite on a call for heat, the air handling system never starts, and the system’s limit control shuts the furnace down.