Model HD Hot-Dawg Unit Heaters: For applications requiring a low profile unit. The Hot Dawg may be installed in residential, greenhouse or commercial applications just one inch below the ceiling. Don't be fooled by cheap Chinese manufactured heaters currently flooding the market. Since 1916, Modine has provided quality heating solutions that are made in America to the highest possible standards. The superior quality matched with the following features makes the Hot Dawg unit heater an easy choice for a variety of applications.
Standard Features
- Made in the USA
- Certified for residential, agricultural and industrial use.
- Quiet operation.
- Attractive low-profile design and neutral paint scheme assure that Hot Dawg will blend inconspicuously into any garage decor.
- Durable polyester-powder paint maintains life-long good looks.
- Standard power exhaust simplifies side-wall or roof venting with small-diameter vent pipe.
- Versatile design allows for right or left-hand piping and installation. Gas, electrical and flue connections can be changed from one side to the other by simply flipping the Hot Dawg over.
- Lightweight, easily installs from ceiling with only 2 angle brackets (included).
- Installs quickly and easily 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 heat exchanger.
- 24,000 thru 75,0000 (HD25A - HD75A) BTUH Heaters will include ceiling mounting brackets. Ceiling mounting brackets for the 100,000 & 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 |
Installation

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
Troubleshooting
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
Manual
Residential Owners Manual (PDF)
Warranty
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.
Free Shipping
This item ships free via Motor Freight Carrier - almost anywhere in the Continental United States!
On rare occasions addresses with limited access such as islands or major metropolitan areas (ie: New York City) may incur additional delivery fees; if so, you will be contacted to confirm the extra shipping cost before your order is processed. Shipments to Alaska or Hawaii qualify for free shipping to any West Coast port. Please contact us for special shipping rates from the West Coast to Alaska or Hawaii.
Motor Freight Agreement
- Full Size Semi: Your location must be able to accommodate a full size semi-truck trailer of up to 70ft. in length.
- Someone Must Be Present: You or someone else authorized must be present to unload the shipment. Exact delivery date will be arranged via phone by freight company.