Defrost Timer Change on AVZC18/20 SEER Inverter Heat Pump Units

Goodman released Service Bulletin SR-072, regarding a software change on AVZC18 and AVZC20 Inverter Heat Pump units:

This bulletin is to inform you of a software change made to the Inverter Heat Pump models listed above. For units with a serial number prefix of 1706 and later the factory default setting for the defrost interval has been changed from 30 minutes to 120 minutes.

The defrost time interval can still be field adjustable to 30, 60, 90 or 120 minutes between defrost cycles to suit weather conditions and unit performance. This setting can be adjusted in the Comfortnet User Menu of the CTK04AE thermostat by selecting “Inverter” – “Heat Set Up” – “Defrost Interval”. When in this Sub Menu select 30, 60, 90,120 minutes setting.

NOTE: Oil Return Mode: In order to properly return the oil to the compressor, compressor speed may periodically adjust to assist oil circulation. These Inverter units utilize an oil return mode to properly return oil to the compressor which functions similar to a defrost cycle and may create the appearance of the unit having unnecessary defrosts.

If you have questions about this bulletin, HVAC Distributors customers can reach out to our Technical Service department at 800.228.4822 x5.

Update: Amana 18 SEER Inverter Heat Pump Now In Stock!

ASX14Goodman Manufacturing announced a new 18 SEER inverter heat pump, with ratings of up to 19 SEER and 13 EER.

The heat pump will be sold in 4 sizes: 2, 3, 4, and 5 ton. Because of the true inverter motor, half-sizes are not required.

The 18 SEER inverter heat pump comes with Amana’s Lifetime Unit Replacement Limited Warranty Coverage (complete warranty details available at

The inverter heat pump must be paired with the CTK-04 communicating thermostat and matches with a new line of Amana electronic expansion valve (EEV) air handlers: the AVPEC family.

Full product specs are here.

The new EEV allows the valve to adjust based on performance load, which improves overall efficiency of the system compared to a TXV. For an explanation of the benefits of an EEV compared to a TXV in variable load situations, click here.

Not sure if inverter technology is right for you and your customers? Check out our cost-comparison calculator to show the first-year and lifetime cost savings of installing an inverter versus other high-efficiency equipment. The results may surprise you.

Note: To purchase Amana inverter product from HVAC Distributors, you must be a registered Amana dealer with HVAC Distributors and at least one person at your company has to have completed the required inverter training. Call your account manager, local branch or our inside sales staff (800.228.4822) with questions.

Amana Inverter Heat Pumps Now at HVAC Distributors

Amana has introduced at 20 SEER inverter heat pump to expand its inverter product offering.

Inverter-certified customers are able to order the inverter heat pump from any HVAC Distributors location, through Web Order Entry or by calling 800.228.4822.

The 20 SEER AVZC20 heat pump features:

  • Daikin’s inverter technology, which uses variable speed swing or scroll compressors
  • Amana’s limited lifetime unit replacement warranty*
  • An efficiency of up to 21 SEER
  • Noise level as low as 57dB
  • An ambient range of -10° to 65° F in heating mode and -10° to 115°F in cooling mode

Amana’s AVZC20 heat pump can be paired with a coil, TXV and variable speed communicating furnace or with the new AVPVC air handler. It must be installed with the ComfortNet™ CTK04 thermostat, which is integral to system installation. All Amana inverter systems require the CTK04.

Product specification sheets, installation instructions, parts & service manuals, and consumer brochures are available on PartnerLink. System ratings are currently available in AHRI. You can also use the System Configurator on PartnerLink (under Dealer Toolkit) to quickly find AHRI approved match-ups.

AVZC20 specifications
AVZC20 specifications

*Complete warranty details available from your local dealer or at To receive the limited lifetime unit replacement warranty (good for as long as the homeowner owns their home) and 10-year parts limited warranty, online registration must be completed within 60 days of installation.

Because this line uses different technology than traditional condensers and heat pumps, Amana-specific inverter certification is required for contractors to be able to purchase this product line. HVAC Distributor’s inverter certification schedule is available here.

To find out more about this product, contact your Account Manager or your local branch.