Arkansas HVACR NewsMagazine January 2026

HVACR NewsMagazine January 2026

Tech News

through numbers 1 – 8 by pressing "Select." Do this until you reach 8, and then press "Option" to confirm it. By choosing option 8, the system will work accordingly: • Type: Demand defrost • Short cycle time delay: 5 minutes • Reversing valve: O • Reversing valve shift delay: 30 seconds • Maximum defrost time: 14 minutes • Enable defrost set point (coil sensor): 35°F • Defrost termination set point (coil sensor): 70°F If you merely want to replicate the OEM's settings, you can cross-reference the existing board's model number on the Universal Defrost Control's box or in the White-Rodgers app. Then, select the matching OEM preset. The table shown earlier has the exact numbers and corresponding settings. Customizing Defrost Parameters You can also set custom parameters by cycling through the menu and entering the time delay, reversing valve power method, reversing valve shift delay, max defrost time, and coil sensor set points manually. As with the OEM quick startup selections, use the "Option" button to cycle through the options and "Select" to pick the one you want.

The tt feature sets the defrost termination temperature. The selection varies quite wildly, with 50°F on the low end and 100°F on the high end. Keep in mind that lower coil temperatures may result in more frequent (but shorter) defrost cycles. You can set short cycle time delays with the SS feature. You can choose from 0, 3, or 5 minutes. Since we do NOT want short cycles, I usually recommend picking 5 minutes. Reversing valve power is determined by the r setting. It should always be set to o (energized in cooling mode) EXCEPT when working in Ruud/Rheem heat pumps. These systems are unique because the reversing valve is energized in heating mode, and that call is on the B terminal ( b ). You can also program a reversing valve shift time delay ( rS ) to reduce loud noises when the unit goes into defrost, as some customers may

The dF menu lets you select timed (t) or demand (d) defrost.

Et stands for enable temperature; this is the temperature that the coil sensor must drop below in order to enable defrost. The selections run from 30 – 36°F in one-degree increments (e.g., you could choose 32°F or 33°F).