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APOLLO Heat Pump - 42k btu / 3.5 ton - Air to Water - EVI Inverter DC technology


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Simply the best air to water on the market. 
APOLLO is designed in the USA.


Main Feature

  • APOLLO heat your house efficiently up to -31°F / -35°C
  • Integrate heating and cooling and DHW system
  • WiFi controller
  • Fan coil, Radiant floor, Radiator, Baseboard, and Pool application

      Bring your PEX and the job is done! (For wiring and breaker size please check download section)

      • Heat: 2500 ft²
      • Capacity: 3.5 Ton, 42K BTU, 12.3KW
      • Heat Pump - Height 23.5½", Width 41", Depth 18", Weight 340 lb
      • CSA/UL Certified for US and Canada
      • Inverter Panasonic Scroll Compressor
      • Green Refrigerant R-410a
      • Variable-speed fan motor
      • Quiet operation

      Warranty: 5 years



      Reviews / Q&A


      APOLLO Air-to-Water Central Heat Pumps

      EVI DC Inverter Technology

      The Apollo series is equipped with advanced technology that can operate in temperatures as low as -31°F.
      Purchase Now

      Apollo Air-to-Water
      Main Features

      • Functions under -31°F

        Smart EVI inverter structure allows stable operation under -31°F
      • Energy Saving

        COP reaching as high as 5.65 for a SCOP, with an annual COP of 4.88
      • Certified Technology

        Over 65k units sold worldwide. UL certified.
      • EVI Full Inverter

        Inverter compressor with an inverter controller and DC fan motor
      • Virtually Silent

        You won't hear it running from 10 feet away
      • Famous Brand Components

        Created with Panasonic compressor and Siemens fan motor technologies.


      Operates well in most temperatures

      Extreme Cold and Heat

      Wide ambient temperature range from -31°F to 110°F. Features include intelligent control, automatic load adjustment in different climates and environments to satisfy the demands of summer cooling, winter heating, and hot water production throughout the year.

      EVI / Full Inverter Technology

      Highly Efficient and Noise-Free

      The step-less inverter compressor, step-less inverter control system, brush-less fan motor, and DC speed water pump are all components of the APOLLO EVI + DC Inverter heat pump. It not only saves energy but is as quiet as a refrigerator, producing 12dB (A) less noise than a standard On / Off heat pump.

      UL Certified

      A+++ Energy Labeled

      This unit is currently one of the most energy efficient, with the potential to dramatically lower customers' energy costs. Its highest COP is 5.65, with a SCOP is 4.88. Our high-efficiency DC variable frequency heat pump uses over 30% less energy than other air source heat pumps.

      Heating / Cooling Time

      50% Faster than Regular Heat Pumps

      Once the heat pump is turned on, the inverter unit quickly selects the best compressor/fan motor operating frequencies. The heat pump EEV will open automatically based on heating or cooling demands. The inverters' fast heating saves up to 50% more heating time compared to traditional heat pumps.

      A must have addon
      All-in-one PUMP STATION

      Because the heat pump itself is only one component of the hydronic installation, the entire system may rapidly become intricate and costly. The APOLLO Pump Station simplifies the entire process: Connect your heat pump + heat exchangers (fan coils, baseboards, radiators) to the Pump Station and you're ready to go.

      Included in the Pump Station:
      • Water Pump
      • Heat pump controller
      • 4KW emergency/booster Electric Heater
      • Expansion tank
      • 3-Way motorized valve
      • Sensors
      • Wiring box


      • Swipe right to browse the table


      Power supplyV/Ph/Hz220/1/60220/1/60220/1/60
      Water Inlet / OutletInch1"1"1"
      Water Flow/ VolumeFt³ / h497691
      Unit Dimension (W/D/H)Inch41/18/23.545.5/20/53.545.5/20/53.5


      COMPONENT3.5 TON / 5 TON / 6 TON
      ControllerFull Inverter Control
      CompressorPanasonic DC inverter compressor
      Fan motorSiemens DC fan motor
      Refrigerant flow controlEmerson Electric Expansion Vavle
      Heat exchangerHigh efficiency tube in shell 

      Heating condition:
      Air DB 68°F / WB 59°F
      Water inlet: 59°F, Water outlet: 131°F

      OUTPUT (heat)Kbtu426072
      INPUT (heat)Kbtu9.21315.7
      INPUT CURRENTAmp12.217.420.8

      Heating condition:
      Air DB 44°F / WB 42°F
      Water inlet: 104°F, Water outlet: 113°F

      OUTPUT (heat)Kbtu35.847.756.3
      INPUT (heat)Kbtu1114.217
      INPUT CURRENTAmp14.81922.7

      Heating condition:
      Air DB 10°F / WB 7°F
      Water inlet: 97°F, Water outlet: 106°F

      OUTPUT (heat)Kbtu22.232.439.2
      INPUT (heat)Kbtu10.515.218.6
      INPUT CURRENTAmp1420.324.8

      Cooling condition:
      Air DB 95°F / - - -
      Water inlet: 54°F, Water outlet: 44°F

      OUTPUT (cool)Kbtu27.342.751.2
      INPUT (cool)Kbtu10.21720.4
      INPUT CURRENTAmp13.622.627.2
      INPUT MAX CURRENTAMP20.53440.7

      Customer Reviews

      Based on 5 reviews
      Matt Lawrie (Seattle, US)
      Just got it. Uninstalled.

      Unit looks well built and was well packed for shipping. I’ll update my review when I’ve installed.

      Simon (Ojai, US)
      Looks like good unit, Long wait!

      Waited several months for delivery of 3.5T unit due to shipping issues and COVID lockdowns.
      Allen and others at MBTek were patient and as helpful as they could be with something outside their control.
      3/4 of my energy bill is for heating between Oct and April. Hoping for a slight overall reduction - it'll depend on future gas prices.

      Unit arrived mid April when my radiant floor system goes dormant until Oct. Lots of time for installation!

      Will update later when it's actually working.
      Getting Inflation Reduction Act grants is extremely difficult - there is no local contractor prepared to take on this install so it's a DIY!

      Everett N.
      Great Solution

      The Heat Pump has been a game-changer for me. It's taken the stress out of heating my home, and I don't have to worry about exorbitant energy bills anymore. It's definitely a must-have for anyone looking for a more cost-effective heating solution.

      Phil V (Whitney Point, US)
      Low Temps = no problem

      Got the 4 ton unit when it was available and so far so good overall. Few "gotchas" that I've worked through with the MBTek Guys and reaching out to other users. The monobloc design made this a overall simple install! Went through a few days already this winter when it was 0F outside, the electric heating element for backup was minimally used to help boost the water temp while the heat pump was going through defrost cycles.

      Genny Burkett
      Good investment

      I've been using the Heat Pump for a while now, and I'm thrilled with its performance. It's the perfect solution for anyone who wants to be comfortable in their home without breaking the bank. It's definitely the best heating investment I've made.

      Speak with an MBTEK Heat Pump Owner in your Region

      Use our interactive map to contact a Mbtek Apollo heat pump owner in your area and ask about their unit.

      Frequently Asked Questions


      Payment and Shipping


      Where can I find a dealer?

      You can speak directly with one of our sales agents via phone, chat, email or text message for more information.

      Who will install my heat pump?

      Mbtek does not complete the installation. Any HVAC professional will be able to install your purchase. If you require assistance finding one, we are here to help.

      Where can I find parts?

      At this link. We have spare parts ready to ship the following business day.

      When will I receive my unit?

      As soon as the unit is in stock, we will book the shipment following business day. The availability (or ETA) of a specific unit is mentioned on the top of each product page. Depending on your location, delivery can take anywhere from 3 to 12 days

      Do I have to pay customs fees if my unit is coming from another country?

      No. We take responsibility for these charges.

      Are your products shipped in the U.S. or Canada?

      It varies for each product. However, we have warehouses in Pennsylvania (U.S.), Alberta (CAN), and Quebec (CAN).

      What is the product warranty?

      The compressor includes a 5-year warranty.
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