ThawPath: a heated catch basin for heat pump defrost ice

The Signal in 30 seconds

This is a real product with a real buyer, and you are unusually well placed to sell it. Cold-climate heat pumps melt their own frost many times a day, that water refreezes under the unit, and owners end up out there with a hammer and chisel.¹ I could not find a purpose-built fix sold in the US, but a Swedish company already holds US patents on the most obvious version,² so the shape of your product matters as much as the idea. Pursue it with three changes: design clear of those patents before you spend a dollar on tooling, sell through installers before you sell to homeowners, and launch on heat cable that is already safety-listed so you are not waiting on certification.³ Your real deadline is the first hard freeze.

What I heard

You are the lead installer at a heat pump company in coastal Maine, and you have spent nine years mounting cold-climate outdoor units on the sides of houses. Every winter the same callback comes in: the outdoor unit has built an ice mound on the patio, the walkway, or up against the foundation, and the homeowner wants it gone.

You have already built a fix by hand. It is a sloped plastic basin that sits on the ground under the unit's existing stand, never touching the unit itself. It catches the defrost meltwater and sends it down a short outlet channel wrapped in self-regulating heat cable (cable that turns its own output up in the cold and down as it warms), out to a gravel drywell or open ground where it can soak away. Six of your customers ran hand-built versions last winter. You want to turn it into a product called ThawPath, sold to installers first and homeowners second.

You have about $12,000 in savings, you are keeping your day job, and you can give this evenings and weekends. You think it could sell for $199 to $249 but you do not yet know what one costs to make. Your biggest fear is putting your savings into molds and then watching a big HVAC accessory company copy it the moment it starts selling.

The scorecard

Score: 7.0 of 10. Verdict: Pursue with changes. The buyer, the pain, and your fit are all solid. The changes are about protection and sequence: stay clear of the existing patents, sell to installers first, and let speed and relationships do the work a patent cannot.

Who would actually pay

Your first and best buyer is the installer: the HVAC contractor who puts cold-climate heat pumps on houses and gets the phone call when ice piles up underneath. For them ThawPath is a line item on the install invoice that prevents a callback, the same way they already sell stands, pads, and line-set covers. They are a countable, organized group. Massachusetts reports more than 1,500 HVAC contractors in its heat pump installer network,⁸ and Maine's community colleges have trained 558 heat pump installers.¹² You do not need all of them. You need twenty who trust you.

Your second buyer is the homeowner who already has a unit and already has the ice. This is the retrofit market, and it is large where you live: Maine passed its goal of 100,000 new heat pumps two years early and set a target of 175,000 more by 2027,¹² and Massachusetts has supported heat pumps in 75,172 homes and businesses since 2019.⁸ Every one of those units in a spot where water cannot drain is a potential customer every single winter.

Cold-climate HVAC installersUtility program contractor networksSupply-house countersGreen-building forumsHomeowners with ice under a unit

Treat price as provisional until real buyers pay. Here is the ladder I would test, and what each rung competes against:

Suggested test: $199 retail for the heated basin and $130 wholesale to installers. That leaves the installer a clear markup on the invoice and gives you a real number to learn from. Every price here is a starting point until you have sold a few dozen.

The demand signal

Direction: a growing installed base, with softer new sales. US heat pump shipments were 3.64 million in 2025, down 11.6% from 4.12 million the year before, with the industry pointing to the refrigerant changeover, tariffs, interest rates, and the end of federal tax credits.¹⁰ Even so, heat pumps still outshipped gas furnaces (3.25 million) for the year.¹⁰ For you the key number is the installed base, not new sales: every unit already on a wall in a cold climate makes defrost water every winter it runs. Climaco, the Swedish tray maker, says an air-to-air heat pump produces 20 to 30 liters of water a day in the cold months.⁹

The factory answer only goes so far. A base pan heater, as one green-building writer describes it, exists "to prevent meltwater that runs off the outdoor coil during the defrost cycle from refreezing before it can drain."¹⁴ It keeps the unit's own drain holes clear. It does nothing about where the water goes after it hits the ground. That gap shows up in owners' own words:

"I ended up using a chisel and hammer to remove a bunch of it... the ice berg was getting too big."¹ (a heat pump owner on a green-building forum, October 2025)

"The one we installed has had the same issue for the past 6 years, the homeowners have learned to live with it"¹ (a professional replying in the same thread, about a unit they installed)

"The water froze before it could completely drain and pushed the plumbing fittings apart."¹⁵ (a heat pump owner in a very-cold-climate thread on the same forum)

"the units drip condensation which freezes on the walkway. During very cold weather, the ice builds up and turns into a mini glacier!"¹⁶ (a mini-split owner on a rural landowners' forum)

"The homeowner has accepted that he's going to have ice every year, though he doesn't like it."¹⁵ (another poster on the same forum, describing a homeowner's unit)

Notice the pattern. People have tried plastic sheets, gravel pits, drain pipes, and heated RV hoses, and the pros have mostly told owners to live with it.¹ That is exactly the kind of problem a simple, purpose-built product can own, provided it actually solves the refreezing, which is where your heated outlet earns its keep.

The 3 things most likely to slow this down

1. The patent fence. Climaco Holding AB holds two active US patents, US10677479B2 and US10941947B2, on a drainage tray that sits between the heat pump and its support, with Google Patents listing expirations in 2037 and 2036.² Your design puts the basin on the ground under the stand, which is outside that description on its face. The catch is that under-stand trays are old news in Europe (Climaco itself contrasts its product with "other drainage solutions where the tray is suspended under the entire stand"⁹), so any patent you get will likely be narrow. Plan for protection to come from speed, installer relationships, and brand, with a patent as a bonus.
2. Electricity, water, and liability. You are putting a heated device outdoors, next to water, next to a house. Launching on a plug-in heat cable kit that is already UL listed and CSA certified (such kits sell for about $34 retail)³ means the basin itself carries no current and you are not certifying your own heater in year one. You still need product liability insurance, clear install limits, and a firm rule that ThawPath never attaches to the unit: New York's Clean Heat program warns that an unapproved attachment can void a heat pump's warranty.¹⁷
3. Seasonality and cash. This sells in a narrow window. If your tooling lands in January you have lost a year, and new heat pump sales dipped in 2025.¹⁰ Keep the first run small and cheap: heavy-gauge thermoforming tooling typically costs about 10% to 15% of comparable injection mold tooling,¹⁸ which is the difference between spending part of your $12,000 and needing an investor.

Closest competitors & the gap

The gap is clear: nobody I could find sells a purpose-built, US-available, ground-level basin that catches defrost water and carries it away without refreezing. Installers improvise, homeowners chip ice, and the one company that has productized this for Europe has not shown up here.⁹ Your opening is to become the default answer installers reach for before that changes.

Can you own it? (patent, trademark, domain)

These are preliminary, informational searches using public tools. They are not legal patent or trademark searches, a freedom-to-operate opinion, or clearance, and domain status can change. Consult a patent or trademark attorney before filing or building.

Where you can claim your name

"thawpath" is open on 9 of the 10 networks. Reddit could not be confirmed automatically.

These are point-in-time availability checks on public profile pages, not a trademark or brand clearance, and a handle open today can be taken tomorrow. Claim the ones you want promptly if you move forward.

How you'd make money

1. Installer wholesale (the core). Sell to installers at around $130 and let them put it on the invoice at $299 to $349 installed. Each installer who adopts it becomes a repeat buyer every season, and your cost to reach the twentieth installer is a phone call and a demo in their parking lot.
2. Direct retrofit to homeowners. A heated basin at $199 sold from thawpath.com to people who already have the ice. Photos of a clean patio next to a chiseled one do the selling. Route installs to your installer customers so the channel sees you as help, not competition.
3. Sizes and add-ons. A larger basin for big multi-zone units, a two-unit basin, extension outlet kits for longer runs to a drain point, and replacement cable. Small tickets, but they lift the average order.
4. Later, license or private label. Once ThawPath has a winter of sales and a list of installers behind it, an HVAC accessory maker that already sells stands becomes a potential partner instead of a threat. Your fear of being copied is also the shape of your best exit.

The brutal truth

Your next 30 days

1. Days 1 to 3: Document your proof. Photograph and write up the six installs from last winter: before, after, and what failed. Ask those homeowners for a two-line quote and permission to use their photos. This is your sales kit.
2. Days 4 to 7: Draw the fence. Book one hour with a patent attorney. Bring the Climaco patents and your design. Lock one rule: the basin sits on the ground, under the stand, never between the unit and its support. Write down, in plain words, what is new about your outlet and drain path, then file a provisional ($65 to $130 in USPTO fees)²¹ once the attorney agrees it is worth filing.
3. Days 8 to 14: Get real costs. Use AI and a free CAD tool to turn your hand-built basin into drawings for two sizes. Send them to three thermoformers and ask for tooling and per-unit prices at 250 and 1,000 units. Price the heat cable in bulk. Now you know your landed cost.
4. Days 15 to 24: Pre-sell to installers. Show the kit to 15 installers you know. Offer a founding price of $130 per unit for this winter with a deposit. Aim for five installers committing to at least 40 units between them.
5. Days 25 to 30: Open the homeowner door. Put up a one-page site on thawpath.com with the before-and-after photos and a waitlist. Share the problem, not the pitch, on green-building and heat pump forums. Count the sign-ups.

Ideas are worth taking seriously, and so are the people who have the nerve to test them. Thank you for trusting me with yours. Whatever you decide from here, decide it with your eyes open, and know that clarity, even hard clarity, is a gift you just gave yourself.

Marty McCrea

Founder, Every Big Idea