Founded
1947
Onalaska, Wisconsin
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Available through CT Greenhouse
L.B. White
A Wisconsin heater manufacturer building forced-air greenhouse heat since 1947, now part of Modine. We buy the Therma Grow line direct and stock both BTU sizes, so sizing questions get answered by someone who actually has the units on hand.
Founded 1947, Onalaska WI
Direct relationship
Forced-air greenhouse heat
Ownership
Modine
Subsidiary since May 2025
Greenhouse lines
9
We stock Therma Grow; the rest is available on request
Warranty
10-year
On the heat chamber and case, against corrosion (Therma Grow)
Buy it where you can ask questions
Why order L.B. White heaters through CT Greenhouse?
A heater is only the right heater if it's sized for your house. We sell what we use and answer the phone when you have questions.
Sizing before you buy
Tell us your house dimensions, what you grow, and your winter lows. We help size the heater to the space before you spend the money.
Stocked and ready to quote
Both Therma Grow sizes, 120,000 and 220,000 BTU, are on hand, so you are ordering from us, not waiting on a factory queue.
Bought direct
We buy the Therma Grow line direct from L.B. White, not through a distributor.
Reachable when you need us
Questions during install or a problem down the road? Call and talk to an owner, not a ticket system.
The greenhouse line
Built for putting heat where the plants are.
L.B. White publishes nine greenhouse product lines. We stock the Therma Grow heaters; the rest of the line is available on request.
01
Therma Grow heaters
Therma Grow 120,000 BTUStocked at CT Greenhouse
Therma Grow 220,000 BTUStocked at CT Greenhouse
02
Other heater lines
BloomCall for pricing
Guardian 2.0Call for pricing
TradesmanCall for pricing
PremierCall for pricing
03
Electric and cooling
Volt (electric)Call for pricing
Reeves Wet WallsCall for pricing
Greenhouse FansCall for pricing
04
Parts and accessories
R Supply ProductsCall for pricing
Line list as L.B. White publishes it. Both Therma Grow sizes are the ones we keep on hand; call about anything else in the line.
L.B. White parts in stock
Order components on their own
Common questions
Buying L.B. White through us
Still have questions? Reach an owner at (860) 341-8707.
Where is L.B. White located, and who owns the company?
L.B. White is based in Onalaska, Wisconsin, founded in 1947. In May 2025 the company became a subsidiary of Modine Manufacturing.
Should the Therma Grow be mounted inside or outside the greenhouse?
L.B. White's own guidance is that it is generally best to mount outside wherever possible, though your climate, the season, and what you are growing all factor into the decision.
What's the difference between the Therma Grow Standard and Plus models?
The Standard model uses galvanized steel construction. The Plus model adds an epoxy primer and powder coat finish, a two-stage gas control valve, and a heat and ventilation-only selector switch.
Can the Therma Grow be converted between propane and natural gas?
The 120,000 BTU model can be converted with a kit. The 220,000 BTU model cannot, due to differences between the heater's base and heat chamber.
Do you carry the full L.B. White line?
Yes. We can get the full L.B. White line, anything they sell, often at the best prices anywhere. Call (860) 341-8707 or send the form below for pricing on anything not on our website.
Get a quote on L.B. White heaters
Tell us about your farm and what you're heating. We will size the heater to the house and price it out.
- Your house dimensions and what you grow
- Guidance on heater sizing and BTU needs
- Pricing on stocked heaters and the rest of the line
- Clear timeline and freight coordination
We stand by our products with a price match guarantee.
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