Alright, let me tell you about this one time I was scratching my head over an AC unit. The biggest headache? The suction pressure was way, way up. Not just a little bit, but enough to make you go "whoa, what's going on here?" When I see that, my brain usually starts running through a list of usual suspects.

My Go-To Checks

So, I started with the basics, the stuff you always check first, you know?

• First thing, popped open the filter slot. A clogged filter can mess everything up, stop the air from moving like it should. This one? Not too bad, surprisingly.

• Then, I took a good look at the indoor coil. Sometimes they get so caked with dust and gunk, it’s like a furry blanket. But no, this one was pretty decent.

• Checked the indoor blower fan. Made sure it was spinning and pushing air. Yep, seemed to be doing its job, hummin' along just fine.

So, the easy stuff was out of the way. No quick wins there, unfortunately.

Digging a Little Deeper

My next thought went to the refrigerant itself. Maybe some eager beaver before me had just pumped too much juice into it. You see that sometimes. Hooked up my gauges, let everything settle down, and yeah, pressures were high all around, suggesting it might be a bit overcharged. I carefully pulled out a little bit of refrigerant, just to see. The suction pressure came down some, but it was still stubbornly high. Not the whole story, then.

Then I started thinking about the TXV, that little valve that feeds refrigerant to the indoor coil. If that thing gets stuck open, it’ll just flood the coil, and boom, high suction. Getting to the TXV on this unit was a real pain, crammed in the back like they didn't want anyone to ever touch it. I gave it a few gentle taps – the old school "persuasion" method – but no change. Still sky-high.

The "Aha!" Moment – And It Was a Bit Embarrassing

I was starting to get a bit frustrated, thinking maybe it was something more serious, like bad valves in the compressor. That’s never a fun job. Before I went down that road, I decided to take a breather and just re-check everything from square one. Sometimes when you're too focused on the complicated stuff, you miss the blindingly obvious.

And boy, did I feel silly. I walked outside to look at the condenser unit again. The homeowner had told me, "Oh yeah, I keep that clean." But when I really got down and looked, especially around the back and sides hidden by some bushes, the coil was absolutely choked with dirt, grass clippings, and all sorts of gunk. It was like it was wearing a winter coat in the middle of summer! It couldn't breathe, couldn't get rid of the heat.

So, what was happening was the system couldn't reject heat outside, which made the whole system's pressure go up, including the suction side. The slight overcharge wasn't helping, but the main villain was that filthy outdoor coil. It was so bad it was probably making the TXV act a bit funny too, trying to overcompensate.

All Cleaned Up and a Good Reminder

I got out the coil cleaner, the good foaming stuff, and really gave that outdoor coil a proper bath. Took a while to get all the crud out from deep inside the fins. Once it was sparkling clean and could actually breathe again, I double-checked the refrigerant charge – it was pretty much spot on after my earlier small recovery.

Fired the system up, and like magic, the suction pressure dropped right down to where it should be. The air coming out of the vents was nice and cold. Problem solved.

It just goes to show, doesn't it? You can have all the fancy tools and knowledge, but sometimes the issue is just good old-fashioned dirt in the wrong place. It was a good reminder for me: always, always check the basics thoroughly, no matter what. Don't just take someone's word for it that "it's clean." Look with your own eyes. That day, the simplest thing was the biggest problem.