Modine Hot Dawg® HD75 Unit Heater

Modine Hot Dawg® HD75 Unit Heater


$1,343.82 Regular price
  • In stock - departs in 2-3 business days

With the Modine Hot Dawg® Heater, you can easily heat commercial warehouses, DIY hothouses `

Modine HD75 Unit Heater Features:

  • Made in the U.S.
  • Certified for residential, agricultural and industrial use.
  • Quiet operation.
  • An attractive low-profile design and neutral paint scheme ensure your Hot Dawg will blend inconspicuously into any garage decor.
  • Durable polyester-powder paint maintains lifelong good looks.
  • A standard power exhaust simplifies side-wall or roof venting with small-diameter vent pipes.
  • Versatile design allows for right or left-hand piping and installation. Gas and flue connections can be changed from one side to the other by simply flipping the Hot Dawg over.
  • The lightweight heater easily installs from the ceiling with only two angle brackets (included).
  • Installs quickly with field wiring connections and knockouts for quick access to gas and electricity.
  • Designed for natural or propane gas.
  • Sealed, permanently lubricated motor for trouble-free dependability.
  • Full 10-year warranty on the heat exchanger.
  • The 24,000 through 75,000 (HD25A-HD75A) BTUH heaters will include ceiling mounting brackets. The ceiling mounting brackets for the 100,000 and 125,000 (HD100A, HD125A) BTUH heaters must be purchased separately.

Dimensions and Diagrams

Dimensions, Diagrams and Specifications (PDF)

Modine Greenhouse Heating Solutions (PDF)

Wiring Diagrams (PDF)

Performance Specifications

Model Application Input BTUH Output BTUH Vent Size Weight (lbs)
HD30 1 to 1-1/2 Car Garage
or up to 250 SF Greenhouse.
30,000 24,600 Requires 3" Vent Pipe 55
HD45 2 to 2-1/2 Car Garage
or up to 350 SF Greenhouse.
45,000 36,900 Requires 3" Vent Pipe 60
HD60 3 to 3-1/2 Car Garage
or up to 550 SF Greenhouse.
60,000 49,200 Requires 3" Vent Pipe 80
HD75 Large Garage
or up to 650 SF Greenhouse.
75,000 61,500 Requires 3" Vent Pipe 85
HD100 Up to 1000 SF. 100,000 82,000 Requires 4" Vent Pipe 125
HD125 Up to 1200 SF. 125,000 102,500 Requires 4" Vent Pipe 125


Many of our customers happily report that purchasing a Hot Dawg heater from the Greenhouse Megastore helped them save 50% or more off the unit price received from a local HVAC installer. However, for safety reasons and to minimize installation problems Modine strongly recommends having a licensed HVAC technician install your Hot Dawg heater. Although we are happy to offer limited technical support for your Hot Dawg purchase, we can NOT install the heater for you over the phone nor are we able to troubleshoot problems you may experience if you choose to install the heater yourself. By purchasing this heater from us, you accept sole responsibility for installation and agree to abide by Modine's limited Warranty


Based on our experience in selling Modine Hot Dawg Heaters, we have written up a troubleshooting guide that deals with the issues we most commonly hear from customers. - Troubleshoot a Modine Hot Dawg

If you still need help, check out Modine's own troubleshooting guide.

Comparison Chart

Modine HD-Series vs. Sterling RF-Series

Specification Modine HD-Series Sterling RF-Series Comments
BTU Range 30 - 125 MBH 30 - 90 MBH Modine covers more applications
Minimum Efficiency 80% 80% Same non-condensing high efficiency
Blower Fan Units
(HDB model only)
60 - 125 MBH Not Available Modine covers more applications
Casing Paint Polyester Powder Wet Enamel Modine units will look better longer
Quiet Swept Wing Fans 100 and 125 MBH Not Available Larger Modine units are quieter
Heat Exchanger Gauge 18 Gauge 20 Gauge Modine heat exchangers are heavier gauge
Optional Stainless Steel Yes Not Available Modine covers more applications for corrosive environments
T.E. Fan Motor Standard Yes No Modine motors are protected for longer life
Power Vented X-Changer Warranty
(HDS and HDC models only)
10 Years 10 Years Same 10 year heat exchanger warranty
Sep. Comb. X Changer Warranty
(HDS & HDC models only
10 Years 5 Years Modine separated combustion units warrantied longer
Component Warranty 2 Years 1 Year Modine parts warrantied longer

Additional Information


Residential Owners Manual (PDF)


Modine offers a 10 year limited warranty on the heat exchanger and a 2 year limited warranty on all other components. Please note this warranty covers parts only and does not cover any labor costs associated with repairing the heater. View Warranty (PDF)

Product Video

Heater Warranty and Return Policy

It is the customer's responsibility to carefully inspect heaters for damage before accepting delivery since heaters are usually not returnable once delivery is accepted. Obviously damaged heaters should be refused and Greenhouse Megastore customer service contacted to make arrangements for a replacement unit. Once delivery is accepted Greenhouse Megastore will gladly provide replacement parts under the manufacturer's warranty to repair damaged or defective heaters; however this warranty does not include any labor costs associated with installing these parts. Warranty issues should be diagnosed by a certified HVAC technician since parts deemed not to be defective by the manufacturer are not available for credit back to the customer. Specific warranty policies vary by manufacturer but typically cover replacement parts as indicated above up to one year after purchase. Please contact Greenhouse Megastore customer service if you have any questions about the warranty for your specific heater.


This item ships via Motor Freight Carrier - almost anywhere in the Contiguous United States

Motor Freight Requirements

  • The shipment must be delivered to a business or residence (a PO Box is invalid)
  • The delivery address must be able to accommodate a tractor/trailer as much as 70' in length
  • Someone must be present to receive and unload the shipment from the truck
  • Shipments and/or locations requiring a lift gate, inside delivery, and/or with limited access may incur additional charges by the carrier

Please contact Greenhouse Megastore Customer Service at 1-888-281-9337 if you have any questions about delivery to your specific address so we can ensure the smoothest delivery possible!

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Customer Reviews

Based on 19 reviews
Casey Young
good heater

heater works great, it was easy to install and set up.

Legacy Review

install went smooth, nice product

Legacy Review

fast delivery , easy to install , fired right up

Legacy Review
Excellent Heater

This heater came with my greenhouse and so far it is doing a great job. It's early Feb 2012 in the NW and I'm busy getting seeds started in the greenhouse. The Modine Hot Dog heats the place up in minutes and the optional thermostat is working like a charm. Just ordered another one for my new shop :)

Legacy Review
Great Heater

Ordered on Monday and the unit was delivered on Wed. It was very easy to install. Used a drywall lift to raise it to the ceiling and bolt it in place. Hooked up the gas and electrical and it fired right up. The unit heats great! Very high quality product compaired to the big box stores. Love it!

Legacy Review
HD75 Modine Heater

Great price, fast shipping and the heater is wonderful...

Patricia Jensen
hd 75 heater reveiw

Easy installation and hook up. Unit started and ran on 1st try.Wind chill outside today -30 degrees below zero. I set heater at 50 degrees and kept garage warm to clean car today.

Legacy Review
HD 75

Hi all just purchased and hooked up 12-11-10. The whole purchase was absolutely painless. Install was easy. Shipping was as I was told it would be. Arrived on time and well packed. Heater fired right up first try and has been heating my 30x40x10 high garage since. Has been in the teens and lower hear lately but is nice and toasty in the man cave. Thanks for an easy transaction Steve

Legacy Review
great heater

Have used in my woodshop for 3 years now and wouldn't consider anything else. Great heater and takes up no usable space.

Legacy Review
hot dawg hd75 heater

FAST shipping, Great product!! NO damage in shipping, and fired up first try.