The evaporator coil of a wine cellar cooling unit seen through its supply grille, the aluminum fins crusted white with ice, a few drops gathering at the lower edge.

WhisperKOOL Ad3: the Anti-Frost cycle timed out on a through-wall unit

Ad3 is the through-wall version of Ad2.

(844) 398-5977

Mon–Sat, 8am–8pm

  • Coil icing and defrost
  • Cellar coil icing and defrost repair
  • Source: WhisperKOOL

Book a visit

Three short steps, about a minute.

or call (844) 398-5977

What Ad3
actually means.

Ad3 is the through-wall version of Ad2. On SC PRO and Slimline LS units, an Anti-Frost cycle stops the compressor for up to ten minutes; if the coil is still not above 26°F afterward, the red light comes on and Ad3 is logged. The unit then runs five minutes and starts another cycle, repeating until the coil warms.

WhisperKOOL wine cellar cooling unit display · also shown as “Ad3”

What to do when Ad3 shows on the wine cellar cooling unit

Before you book,
in this order.

Each step comes from WhisperKOOL's own guidance for Ad3 on its wine cellar cooling units. Follow it to the end: the last card says whether this is a visit.

01

Check the cellar-side coil for ice; unplug the unit and let it thaw before restarting.

02

Make sure the intake air on the cellar side is not below 60°F.

03

Clean the filter and clear anything blocking the grille.

04

If the unit keeps cycling into Anti-Frost about every five minutes, book a visit.

Still there?

It usually turns into cellar coil icing and defrost repair. Book with the code and the model number.

What not to do

Ad3 does not appear on WhisperKOOL split or ducted units; they log Ad2 instead. A single defrost message without Ad3 is normal operation.

What you may
notice with it.

The wine cellar cooling unit problems Ad3 tends to arrive with. Answer these at the wine cellar cooling unit before anyone is booked.

All problems

Where Ad3 usually leads

Cellar coil icing and defrost repair.

Thawing an iced coil and correcting its cause · low to moderate.

In WhisperKOOL's own words

Anti-Frost Cycle ended on time-out
WhisperKOOL SC PRO Series owner's manual (12/2022) WhisperKOOL SC PRO Series owner's manual (12/2022) WhisperKOOL SC PRO Series owner's manual (12/2022)

Every code on this site is taken from the manufacturer's documentation, never from a forum or a parts listing. SC PRO and Slimline LS through-the-wall controllers.

WhisperKOOL Ad3 wine cellar cooling unit repair,
where we come out.

The same visit in every metro below: the code, the model number, and a diagnosis before any part is ordered.

All service areas
A couple lifting a bottle from a lit stone-walled wine cellar, the cooling unit's grille high on the far wall
For the heart of your home.

Questions
about Ad3.

Can I clear Ad3 myself?
Check the cellar-side coil for ice; unplug the unit and let it thaw before restarting. If it comes back, it needs a visit.
Why does my WhisperKOOL SC PRO stop and start every few minutes?
Repeated Anti-Frost cycles do that: five minutes of running, then another defrost. With Ad3 logged, the coil is not warming enough between cycles.
Can a cold cellar cause Ad3 on a WhisperKOOL?
Yes. WhisperKOOL asks for intake air of at least 60°F; a cellar set very low can keep the coil frosting.
Where do I see Ad3 on a WhisperKOOL SC PRO?
The red alarm light shows in the corner of the display, and Ad3 is recorded in the alarm folder.

Back to your everyday

Still showing Ad3?

When you book, type the code or the blink count as the controller shows it, add the full model number, and say what the thermometer in the cellar reads now — that gives the technician a head start.

(844) 398-5977 Schedule a repair