Market Refrigeration TXV Adjustment

This quick article was written by market refrigeration tech Clayton Peeples. Thanks, Clayton!


Adjusting the TXV should be done last after checking all other causes of the case being warm or floodback on the rack. TXVs very rarely go bad; generally, it's a dirty screen or a failed powerhead, both of which can be addressed without replacing the valve.

Before adjusting the TXV to raise the superheat, you need to ensure that the screen is clean by pumping the system down and checking the screen.

After the screen is clean and you have ensured that there is no ice in the case, then you can start by checking the superheat with your digital gauges or probes.

If the superheat is at zero, it is best to start over using the following method to prevent floodback:

Danfoss  – Turn all the way in clockwise. Then, go out 5 ¾ turns counterclockwise. Let it set and equalize, and then check after 15 mins.

Sporlan – Turn all the way in clockwise, and then go out 4 ½ turns counterclockwise. Let it set and equalize, and then check after 15 mins.

The goal is a 6-12-degree superheat. When adjusting, make minor adjustments, and then let it sit and wait for adjustments to show. 

—Clayton

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Related Tech Tips

Getting the Most From Value Engineering
This article is based on the January 28th episode of the HVAC School Podcast: “How to Value Engineer Better w/ Alex Meaney,” Which you can listen to HERE. Simply put, value engineering is the process of finding ways to cut costs out of a project WITHOUT creating quality issues. As Alex stated, 2+2 doesn’t always […]
Read more
Priorities of an Ideal HVAC System Design
There is so much to consider on any sort of design project, and HVAC system design is no exception. Unfortunately, the priorities of engineers, builders, customers, and HVAC contractors don’t always align when it comes to designing and installing the “ideal” HVAC system. On the one hand, the customers may prioritize aesthetics; they don’t want […]
Read more
Start Capacitor and Inrush Facts & Myths - Part #3
Before we get into the parts that will ruffle some feathers, let's talk a bit about what a “Start” capacitor is and what it does. First, let's review that both start and run capacitors connect between the leg of power opposite of compressor common and the start winding. Even though it seems like a run capacitor […]
Read more
loading

To continue you need to agree to our terms.

The HVAC School site, podcast and daily tech tips
Made possible by Generous support from