What the heck is a TXV If you're watching this video, you may have had a contractor tell you recently that you have a failed TXV thermal expansion valve and in this video we're going to talk about what exactly. That is why it's so expensive to replace and if you stick around to the end, I'm going to give you a piece of information or a tip that a lot of contractors themselves don't seem to even know. So first my name is Josh I Host the HVAC guide for homeowners YouTube channel and let's Dive Right into this: What is a TXV Basically in the flow of refrigerant and an AC system, a TXV is simply the metering device that meters the refrigerant before it goes through the evaporator coil it's needed because if it weren't there, the coil would not be able to cool. You would essentially have a compressor that was pulling liquid refrigerant all the way through the evaporator coil and back to the outdoor condensing unit.

And so in the old days we used to have what we called Pistons a small mechanism in there that just simply had a small hole in it and that's what would meter the refrigerant. But As time has gone on, better technology came out and they started producing these TXV valves that could open and close based on the temperature that the valve was sensing. I'm thinking like a toasted cheeser. It's so hot here so if you've got a pro that has come to you and said hey, you've got a failed TXV we've got to replace that.

It is not a part typically that you're going to be able to repair if it's not opening and closing like it should. or maybe it's gotten some sort of trash or some sort of gunk in there. Something is causing that. TXV Not to operate like it should.

and in most cases it needs to be replaced. And a lot of times the part itself is not that expensive. What happens though? contractors have to account for the labor to install it, the refrigerant that may need to be put back in the system, the brazing materials if they have to braise it in. So it's not just the part itself, but they've got to account for all of this extra stuff, such as the materials or the labor to install that part.

Okay, that's enough. Stop playing. and I would even argue that if they are replacing the TXV anytime that system is cut into any way, shape or form, the filter dryer should also be replaced. Now we have heat pump systems and so these systems have the ability to literally run backwards with a reversing valve.

A lot of folks don't realize you have metering devices on a heat pump system on the indoor unit and the outdoor unit. somewhere in that system that has to meter the that refrigerant. Now there's exceptions to that rule Mini Splits being one of them. but most heat pump systems, you're gonna have a TXV on the indoor Unit A TXV on the outdoor unit.

Now let me say this. now that time has gone on, we also have all these new terms. We have Eevs and Exvs and Tevs. They're basically all doing the same thing different verbages.

Some of them are electronic expansion valves, Some of them are thermal expansion valves that mechanically open and close based on what the temperature bulb is sensing and ultimately they're all still some sort of valve that may need to be replaced if it has failed. I Did want to point out though, if you have one of these newer electronic or some sort of communicating valve with a coil that sits on top of the valve itself, some Brands call that a stepper motor. Some of them it's just basically a solenoid. but whatever that call that part, sometimes it's just that little solenoid part.

It doesn't mean that the entire valve needs to be cut out and then re-braised back in. but the last thing I'll say that I pointed out at the beginning of this video. a lot of Txvs are misdiagnosed and what I mean by that? Sometimes when I've been working with contractors or homeowners if they sign up for our guide, there's been times that I have had to ask some tough questions to some contractors who have said yes I've got a failed part here I've got a failed TXV and I'll ask them questions. Can I ask you a personal question did you put it in charging mode and I've found that as time has gone on with these newer technologies that a lot of contractors are misdiagnosing these systems.

when in reality You've Got A system that might be low on refrigerant or maybe some other low voltage issue is going on I Would probably say in a lot of cases unless you have a contractor that you have a lot of confidence in that you've worked with for years and you've got that connection with and they've always done you right. I Would recommend getting a second opinion if you've been told that your TXV has failed. I Can't tell you how many times we have been called when a company has said yes, a TXV has failed. It's going to be one or two grand to get this thing straight.

I declare bankruptcy hey and we come in and just find out that it's just slightly low on refrigerant. Now that's a whole nother pickle in itself. It doesn't necessarily mean that the TXV is bad. The problem with all of this is if they were to diagnose the TXV as bad and they were to sell you the job, they were to cut out the old one, put the new one in, pull a vacuum, put all the new refrigerant in there.

they themselves a less experienced HVAC Tech might say hey, I fixed this I got it straight I told them what was wrong, we got that part replaced now I've added the refrigerant, the proper amount of refrigerant in there and it's running like it's supposed to when in reality. the only real fix they did was they got the refrigerant right after they replaced a TXV That wasn't necessarily bad. Now Do Txvs go bad? Absolutely. They go bad all the time.

Ain't nobody got time for that? So this is not me saying that every time a contractor has told you that a TXV is bad, that he's wrong. But we have seen a lot of them misdiagnosed contractors thinking that because they're getting wonk pressures, that the TXV must be bad. Only to find out that the TXV itself is not actually bad and that ain't bad. So last thing I'll say is what do you do if you're a homeowner and a contractor has told you that you need to have a TXV replaced I would get a second opinion.

I would also make sure they replace the filter dryer when they replace that TXV and make sure that they're adding fresh, new refrigerant, virgin clean refrigerant into that system after that TXV was replaced. We see things done all the time, such as brazing techniques without an inert gas, they're putting junk in the system and they're creating more issues which does make Txvs and other devices fail in that system. Ultimately, if I'm seeing wonky pressures or some sort of odd pressures with my suction and my head pressures a lot of times, again, you might have a valve that's opening more than it should because it's starving for a refrigerant based on that temperature sensor. Unless I've got a TXV that is completely stuck, closed, or completely wide open something like that.

If I can see that a TXV is opening and closing like it should, but just giving me odd pressures, I might actually check my airflow, my static pressures, and of course refrigerant levels to make sure that that TXV is actually the problem. I Have seen it done where folks will diagnose a bad TXV and it was really only a dirty coil. So anyway, I hope that helps. Thanks for watching.

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