Renu Therapy Cold Stoic 3.0

The Cold Stoic 3.0 is Renu Therapy's answer to a specific buyer problem: wanting both a cold plunge and a hot soak without installing two separate tanks. At $11,399, it's priced above every cold-only competitor in our database, and the spec sheet shows exactly where that premium goes — and where it doesn't.

One Tank, 67-Degree Swing: What You're Actually Paying For

The 3.0's integrated chiller-and-heater covers 37°F on the cold end up to 104°F on the hot end, controlled from one touchscreen or WiFi app, inside a single 40" x 25" x 31" tank. That's the entire value case for the higher price tag versus a cold-only tub. If you know you'll never use the hot side, you're paying for a function you won't touch — run the numbers against a cold-only unit like BlueCube's D1 before assuming the dual range is worth the premium for your use case.

0.5 HP Chiller, 518W Cold / 1,013W Heat: The Real Performance Numbers

Renu rates the chiller at 0.5 HP, drawing 518 watts on the cold cycle and 1,013 watts on the heat cycle, with a stated 58-decibel noise level measured at roughly 3 feet — about dishwasher-level, not silent. This generation's chiller was specifically upgraded from the 2.0 to hold performance more consistently as ambient temperature swings, which matters if the tank is sitting outdoors through summer heat rather than in a climate-controlled space.

Dual-Stage Filtration Plus Ozone: What It Actually Reduces

Water treatment runs through an external quick-swap filter for large debris, a higher-capacity internal filter for fine particles, and an integrated ozone generator that cuts down on bacteria and organics without relying entirely on chemical dosing. It's a lower day-to-day maintenance load than a manual-fill ice bath, where full water changes happen far more often — worth factoring in if ongoing upkeep time is part of your decision.

365 lbs Empty, 1,155 lbs Filled: Confirm Your Surface Before You Order

Outer footprint is 70" L x 33" W x 35" H; filled to the 95-gallon working capacity (134-gallon max), the unit weighs roughly 1,155 lbs. Check your deck or patio's load rating before placement — this isn't a unit you reposition after the fact. Electrically, Renu specifies a dedicated 120V/15A circuit with a GFCI plug and a 12-foot cord; if you're unsure your existing outlet meets that, read our breakdown on sizing your electrical circuit before you buy before you order, not after delivery.

The Warranty Split Buyers Miss: 5 Years on the Body, 1 Year on the Chiller

Renu markets this as a "5-year limited warranty," but that term applies to the tank body — the chiller, which is the component most likely to actually need service, is covered for just 1 year. That's a meaningfully shorter window than the headline number suggests, and it's the exact kind of split we break down in our guide to reading "limited" warranty language before you buy. Factor a possible out-of-warranty chiller repair into your real cost of ownership past year one.

Cold-Only Competitors Cost Less — Here's When That Matters

BlueCube's D1 and the Ice Barrel 300 + Chiller Bundle are both cold-only, at lower price points, and Morozko Forge is built around genuine ice-forming rather than any heat function. The 3.0 only wins that comparison if you actually intend to use the 104°F side regularly. Run the full price and spec comparison on SaunaPlungeHub's Compare tool, and check Renu's standing on our Trust Score leaderboard before you commit.

How to Use

1. 1
   Step 1 of 7

   Confirm Your Circuit Before You Order

   Verify a dedicated 120V/15A GFCI circuit reaches your install site — this isn't optional, and retrofitting it after delivery costs more than checking first.
2. 2
   Step 2 of 7

   Check Your Surface Load Rating

   Confirm your deck, patio, or slab can support 1,155 lbs filled weight before placing the unit; this isn't a tank you move once it's full.
3. 3
   Step 3 of 7

   Fill to the Working Line, Not the Max

   Fill to the 95-gallon working line using a standard garden hose — the 134-gallon mark is the hard maximum, not the recommended fill.
4. 4
   Step 4 of 7

   Set Cold or Hot Mode and Let the Chiller Work

   Select your target temperature via touchscreen or app; a full swing from ambient to 37°F or up to 104°F takes several hours, not minutes.
5. 5
   Step 5 of 7

   Leave Filtration and Ozone Running Continuously

   Keep the dual-stage filter and ozone system running between sessions rather than cycling it on and off — this is what keeps water clear without manual chemical dosing.
6. 6
   Step 6 of 7

   Time Sessions Based on Mode

   Cold sessions typically run 2–5 minutes for most users; hot sessions run 15–20 minutes. Adjust based on your own tolerance, not a fixed rule.
7. 7
   Step 7 of 7

   Replace Filters on Renu's Schedule, Not by Guesswork

   Swap the external reusable filter and internal XL filters on Renu's stated maintenance interval — skipping this is the most common cause of cloudy water complaints in this tank category.

The Cold Stoic 3.0 has become a real part of my daily routine rather than a novelty. The build quality stands out immediately — no cheap plastic, clean lines, easy to drain and maintain, and it holds a consistently cold temperature. It fits well whether I'm doing a breathing routine beforehand or just using it after a long workday. It's become something I genuinely miss when traveling, which says more about it than any spec sheet could.

I tried a cheaper cold plunge a couple of years back just to test whether I'd actually like the routine, and the benefits exceeded what I expected. When I remodeled my spa area, I narrowed it down to two brands — a friend went with a competitor and ran into a string of issues with some of the worst customer support he'd dealt with. I went with Renu instead and I'm glad I did. It's well built, runs quiet, and the controls are straightforward. Six weeks in, I love it. It's not the cheapest option out there, but it's been worth the extra cost for the build quality.

Awesome cold tank, exactly as advertised. Easy to operate, low-maintenance day to day, and the customer service backing it up has been genuinely great.