We also had a DIY opportunity recently with one of our A/C units that had been acting up. Neither of us had ever done any HVAC repairs and struck out trying to diagnose it ourselves. We ended up having to call a professional to come out and took a look. As it always happens, the A/C decided to work perfectly while he was here, but he was able to tell us what part might be failing based on our description of what had been happening (it's called a relay in case you're interested). $89 later, he was on his way and gave our A/C a clean bill of health…which lasted until that very evening when it started acting up again.
Armed with the information I thought necessary to fix the unit ourselves, we embarked on a journey to find a replacement part. I quickly learned that HVAC is not like other home repairs. Your typical home improvement store is much more interested in selling you a completely new system and doesn't even have replacement parts in stock. I found some smaller shops that had parts like what I needed but couldn't tell me with certainty whether what they had was compatible. Even YouTube couldn't give me much information about what to be looking for or how to swap a part. After reading up on things, I walked away with the impression that there are likely A/C units that are fully replaced when the actual need may be something much smaller. This works because this industry has a lot more information assymetry than others and most people don't seek out multiple opinions and simply go with the sure solution of a complete replacement.
This little thing does something to control the air handler blower to switch on and off…a good thing to have working in August.I ended up finding a manual online for the part of the A/C unit in question and learned how to decode the part number and how to tell whether a different part number might also be compatible. This time, eBay was the winner. I got the part I needed for $13 after shipping and after only about 10 minutes the old part had been swapped out and we were back in business. We still had to pay $89 for the first guy to come out, but I'm sure it would have been a lot more than $13 for him to have swapped out the part.
In this day and age, we could literally hire out every aspect of our lives if we wanted to. I don't begrudge people for trying to earn a living, but individually we all need to decide what's the right level of outsourcing for us. I can't always figure things out on my own but enjoy the sense of satisfaction and boost to self-confidence that comes with doing something myself when I can.