Santa Fe Ultra series / Ultra-Aire 70H and 120H whole-house ventilating dehumidifiers (Ultra70, Ultra120): quick sheet

Covers: Ducted whole-house ventilating dehumidifiers from Therma-Stor (Madison, WI): the Ultra-Aire 70H (now sold as the Santa Fe Ultra70) and Ultra-Aire 120H (now the Santa Fe Ultra120). 2024-on Santa Fe Ultra units use R-454B; the older Ultra-Aire 120H manual lists R-410A. Other Ultra-Aire models (120V, 98H) exist and have different numbers.

Single sourceBrands: Santa Fe, Ultra-Aire, Therma-Stor4 components

A stand-alone dehumidifier that ties into the home's ducts (its own return, supply into the HVAC supply or return), with an optional 6 in fresh-air inlet for ventilation and a MERV-13 filter. It has no built-in control on the 120H: a low-voltage dehumidistat (the DEH 3000 or a remote dehumidistat) must be wired to it. Calls are usually control wiring, a tripped transformer breaker, low-temperature defrost cycling, drain trap problems and dirty filters.

Safety first

Unplug before opening the cabinet.
Do not let the 24V terminal touch COM / DMPR or the transformer will be damaged.
Sealed-system work (leaks, compressor, charge) is EPA 608 work for a certified technician: diagnosis and referral only.
Use a GFCI-protected outlet where the area can get wet.

How it works

A low-voltage (24 V) control on the unit's terminal block tells it what to do: closing 24V to DEHU runs the fan and compressor; closing 24V to FAN runs the fan only. A 40 VA transformer inside powers the relays and can also power small HVAC accessories from COM and 24V.

FLOAT terminals accept a normally closed float switch or water sensor; opening that circuit stops the unit. If a condensate pump is used, its safety float goes here.

Operating range is 49-95 °F inlet air. In a cold space the unit cycles through defrost (a defrost thermostat on the coil); short compressor cycles in a cold crawlspace can be normal.

Transformer protection is a push-button circuit breaker near the power cord. If it trips, find the low-voltage short (often control wiring) before resetting.

Condensate needs a trap. The 120H manual calls for a 3/4 in male NPT adapter, 3/4 in PVC drain and a pitch of about 1 in per 10 ft. A drain pan with a float switch is required if the unit sits above a living area.

Components & tests

Unlock all 4 components, specs, service mode and teardown

Full library + AI assistant + the OnCall Tech app for iPhone & Android. $34.90, one time.

Get lifetime access

Official manufacturer documentation

Always confirm values against the tech sheet for the exact model.

Santa Fe (Therma-Stor) whole-house dehumidifiers

OnCall Tech is a reference tool for trained technicians and can make mistakes. Always disconnect power and confirm with the manufacturer's documentation before you work. © 2026 OnCall Tech. Original content; not a reproduction of any manufacturer document.Generic part photos (not of this brand): Large rental dehumidifier unit on a job site by DesiccantDryAir, CC BY-SA 4.0

Diagnostic guides for this appliance

Guide · Dehumidifier

Dehumidifier error codes: general approach (sensor, bucket, pump)

Many portable dehumidifiers (TCL, Honeywell and similar platforms) use the same code groups: sensor faults (E1/E2/EH), bucket (P1/FL), pump (E5/P2) and refrigeration protection (E3/EC). Codes are not universal: on Frigidaire, E5/H3 is compressor overload, PU is the pump and EC/F0 is a sealed-system fault. Power-cycle and basic checks fix many; sensor faults need a part.

4 steps ~30 mineasy

Guide · Dehumidifier

Dehumidifier won't turn on (no display)

Check outlet, cord and any reset button first. Then internal fuse, transformer (on some whole-house units) and the control board.

4 steps ~45 minmoderate

Guide · Dehumidifier

Dehumidifier humidity reading wrong or runs nonstop

Compare against a known-good hygrometer. A dusty or failed humidity sensor, a set point too low for the space, or an undersized unit makes it run nonstop.

3 steps ~30 mineasy

Other dehumidifiers manuals

Manual · Dehumidifier

Hisense 35 / 50 / 70-pint dehumidifiers (DH-35K1SCLE to DH-70KP1SLE): quick sheet

Hisense portable dehumidifiers covered by one use and care guide: DH-35K1SCLE, DH-50K1SDLE, DH-70K1SLE, DH-50KD1SDLE and the pump models DH-50KP1SDLE and DH-70KP1SLE (KP = built-in pump), plus the similar DH50K1W, DH50KP1WG, DH70K1G and DH70KP1WG. No CPSC recall for Hisense-branded dehumidifiers was found (the big dehumidifier recalls were Gree, New Widetech and GD Midea units), but check the model against cpsc.gov.

5 components5 common failuresHisense

Manual · Dehumidifier

Danby DDR dehumidifiers (incl. recalled Gree-built and New Widetech-built units): quick sheet

Danby portable dehumidifiers with the DDR model prefix (Danby, Danby Premiere, Danby Designer, plus the Danby-made Generations GDR and ArcticAire ADR lines). Two recall groups matter on every call: the Gree-built units recalled in 2013 (DDR3011, DDR30P, DDR4511, DDR45P, DDR6511, DDR65CHP, all date codes, sold January 2005 - August 2013) and the New Widetech-built units recalled in 2021 (made before September 1, 2017, sold February 2009 - August 2017, e.g. DDR45A3GDB, DDR70A3GDB, DDR60RGDD, DDR25E, DDR30E, DDR45E, DDR5009REE, DDR6009REE, DDR7009REE, DDR50A1GP, DDR60A2GP, DDR70A1GP, GDR5011BL). Current models (e.g. DDR020BJWDB through DDR050BJWDB, DDR060BECWDB) are later builds.

5 components6 common failuresDanby, Danby Premiere, Danby Designer

Manual · Dehumidifier

Honeywell / Resideo TrueDRY DR65 and DR90 whole-house ventilating dehumidifiers: quick sheet

TrueDRY DR65 (DR65A1000, DR65A2000) and DR90 (DR90A1000, DR90A2000) ducted whole-house dehumidifiers sold through HVAC distributors, mostly 2010s installs. Discontinued; parts support varies. Figures below are from the A2000 spec data sheets unless noted.

4 components4 common failuresHoneywell Home / Resideo