Replacing HVAC Thermostatic Expansion Valve

[Robert LaPlaca]

The Bryant central air conditioner unit for my shop has been diagnosed with a faulty Thermostatic Expansion Valve (TXV), the unit is 9 years old. The air handler is installed in the attic of my shop, in what I would term as a fairly tight quarter.

I was quoted a cost for the repair from the HVAC company that installed and routinely services the HVAC units in our home for the repair, the price quoted kind of floored me..

I was wondering if any of the member of the forum have any experience replacing TXV’s on their HVAC units, was curious as to the cost of their repairs..Just wondering if I am being cheap, or my HVAC company needs to sharpen their pencil a bit..

TIA

[Tom M King]

To get someone else to replace it will probably cost close to as much as replacing the whole air handler. Even though I could do it myself, if I needed to replace a nine year old TXV, I'd just replace the whole air handler.

Just examples:

https://www.supplyhouse.com/Carrier-...t-3-to-3-5-Ton

https://24hr.supply/bryant-fb4cnf042...QaAm_UEALw_wcB

[Robert LaPlaca]

Thanks Tom.

Your correct, the price quoted was pretty much the cost of the new air handler.. I was wondering after given the quote to replace the TXV, if I just would be better off with a completely new HVAC system in my shop.

[Stan Calow]

Robert, what were the symptoms of the TXV failing?

[Robert LaPlaca]

Stan,

The issue was no cold air, the start capacitor was initially bad.After the start capacitor was replaced, the tech was using the gauges and line set probe to see if the refrigerant was being circulated. Very little cold air was being sent to the shop. Was diagnosed as bad TXV..

[Tom M King]

Was the whole system, including the lines, new nine years ago?

[Robert LaPlaca]

Tom, the whole garage and workshop was built 9 years ago, so the entire HVAC system was installed during construction.

[Tom M King]

Did the tech go up in the attic to look at the TXV? Line frosted up? Does it have an inlet screen access port?

[Robert LaPlaca]

Tom, yes the tech went up in the the attic. I was told the line was starting to freeze. I don’t know what an inlet screen access port is, so cannot answer your question. Just as a FYI, the attic is really tight quarters, maybe 24” headroom, so I have never been all the way in the attic..

[Tom M King]

That would make it much more aggravating to change out the TXV. Is there a big access door below the air handler to lower it down and get another one up there? How large is the shop?

[Bill Dufour]

I do not know home ac but on some cars the system has to be discharged to change out the expansion valve. Then. evacuated, then the refrigerant pumped back in.
Bill D.
For a shop the more efficient multi speed system is probably not a big deal. You want it cool or off when not in the shop. Multi speed is for systems that run a long time day or night.
Bill D

[Tom M King]

Yes, the system has to be evacuated to change the valve, and also just to clean the inlet screen, if it has one.

[Tom M King]

It probably also requires brazing in already tight quarters inside the air handler. I wouldn't even try it without one of these:

https://www.amazon.com/Uniweld-MTF-5...ustomerReviews

[Bill Dufour]

Reminds me of Jack Londons fancy house built with book proceeds near Santa Rosa. Plumbers burned it down the night before he moved in. He lived in the cabin on the property for the rest of his life. The basement foundation is a state park.
Bill D.


https://london.sonoma.edu/beauty-ranch/wolf-house

https://jacklondonpark.com/product/j...-3-wolf-house/

[Robert LaPlaca]

That would make it much more aggravating to change out the TXV. Is there a big access door below the air handler to lower it down and get another one up there? How large is the shop?

Tom, the tight quarters would make changing the TXV more challenging for sure. There is a 30” x 30” access door to the attic, it like I previously stated it’s really tight quarters. I am guessing the shop is 600 sq ft.