HVAC Diagnostics: Don’t Take ‘Won’t Blow Cold Air’ for an Answer

No one has time for vague failure descriptions. Literally. A work order that says, “A/C won’t blow cold air” is going to soak up a lot of hours in the service bay compared to one that’s more descriptive and thorough.

If you’re a distributor or dealer, talk to your counterpeople or service reps about the importance of a clear failure description on a work order. It only takes a few simple questions.

Your conversation with the operator might go like this:

Q: What’s the situation?

 Won’t blow cold air.

Q: OK. When did the system stop cooling?

About an hour ago.

Q: What steps did you take when you noticed the lack of cooling?

I cranked it up to maximum cool. When it still wouldn’t work, I turn off the A/C and just opened the window.

Q: Is this a new problem or have you noticed it before?

In the last few days I’ve had problems off and on. This is the first time it happened when I was close to a place that did A/C service.

Q: Do you get any cooling at all?

 Yes, but it quits after a while.

Q: Do you feel any air coming through the vents from the blower?

 Yes. The air is getting through but it’s kind of warm.

Q: When was your air conditioner last checked or serviced?

Maybe a year ago.

Q: Has the heater been used recently and did it work OK?

Yes.

Q: Have you had other service problems in the last few months?

No. (If the answer is yes, ask when, where, and what was fixed?)

So, with a little more information, a clearer picture starts to emerge: the A/C cools for awhile and then blows warm air; the system hasn’t been maintained in a year; and there are no complaints about the heater. Based on what the operator said, it’s possible there’s a leak and a low-pressure cutout switch is cutting the circuit to the clutch, protecting the compressor. 

Your next step: recommend a complete inspection to find the problem.

So where does this leave your customer?

He has some options. He can give you the go-ahead for full service and repair now, wait until you’ve inspected the system to determine cause and cost, or delay repair until he has some downtime available.

It’s a heck of a lot better than than writing up a work order to “check things out.” And your technician will have a better handle on how to troubleshoot the problem.