Our upright pick
Nordic Wave Viking Premier Cold Plunge
Upright plug-in plunge that chills to 35°F on a 36 × 30 in footprint
$5,990
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Renu TherapyCold Stoic 3.0
Hot-and-cold plunge tub, 37 to 104°F, with published power use
Source-based analysis, not hands-on testing. Our method
Cofounder of Superhuman Chambers · About the author. General information, not medical advice. No independent clinical review is claimed.
The verdict
The Cold Stoic 3.0 is a 95-gallon tub that both chills and heats, from 37°F to 104°F, with ozone, two-stage filtration and Wi-Fi control. Renu publishes its 24-hour average power draw, so you can estimate running costs. The catch: it's $11,399 before the $400 insulated cover, the chiller is covered for only 1 year, and the manual's 1.5 to 3°F per hour cooling rate is slow.
The trade-off
The chiller gets only 1 year of coverage (other covered components get 5 years), returns cost 5% plus shipping, and a fresh fill cools slowly at the manual's rate.
Model reviewed: Meterous Black finish, California Redwood deck, included basic tub lid (SKU AS-CS30-BK-RD)
$11,399
Check price at Renu Therapy US price, checked
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About this price
List price for Meterous Black / California Redwood / Included Basic Tub Lid (SKU AS-CS30-BK-RD) on Oct 13, 2026. Renu's product page and online store both showed it, with no sale price or crossed-out regular price. The same finish with the insulated spa cover is $11,799. Pacific Cedar adds $200 and each composite deck adds $300, so options take the price up to $12,099. The page showed a "Sold Out" label beside "Add To Cart • $11,399", but Renu's online store marked this version available. The page also says "Ships in 3 - 5 weeks." Delivery is free curbside within the contiguous US, and the price is before tax.
A GOOD FIT FOR
You want cold plunges and warm soaks at home from one tub, you can give it a dedicated 120 V circuit, and you can handle curbside delivery of a 365 lb tub.
- You want cold plunges and warm soaks from one tub, and Renu gives it a 37°F to 104°F range
- You want to estimate running costs from a published 24-hour average power figure
- You have a level, water-resistant spot that can carry about 1,155 lb filled, with a 120 V circuit nearby and room for the 15 in and 27 in vent clearances
THINK TWICE IF
- Anyone who needs a fast cool-down from a fresh fill, since the user manual gives 1.5 to 3°F per hour
- Gyms, clinics and other commercial settings, since the warranty covers only non-commercial home use
- Anyone who can't move a 365 lb tub off a pallet after curbside delivery
What still needs checking
- Shell material (the warranty page groups the tub with Renu's plastic tubs but names no material)
- Whether the unit carries an electrical safety listing such as ETL, UL or CSA
- Price of the extended chiller warranty
- Price of a replacement primary filter
- How often the XL filter actually needs replacing rather than cleaning
- Ambient temperature, cover use and test method behind the 130 W and 260 W average power figures
- Whether the primary filter is reusable (product page) or replaced every 2 to 4 weeks (user manual)
- Cord length (12 ft GFCI or 9 ft standard)
- Filled weight (1,155 lb on the page, about 1,165 lb in the manual)
- Whether it's actually in stock: the page showed a "Sold Out" label, but Renu's online store marked this version available
- An indoor or outdoor rating: the page says the tub is designed to withstand harsh weather, and the warranty page mentions weathering of the natural wood decks on outdoor units, but neither gives one
- Whether the app carries any fee
The practical details.
| Exact variant | Meterous Black finish, California Redwood deck, included basic tub lid (SKU AS-CS30-BK-RD) |
|---|---|
| Temperature range | 37°F to 104°F from the integrated chiller and heater |
| Chiller and heater | 0.5 HP chiller and 1 kW heater. The user manual gives cooling at 1.5–3°F per hour and heating at 4–6°F per hour |
| Water capacity | 95 gallons at normal fill, 134 gallons maximum |
| Weight | 365 lb dry, about 1,155 lb filled |
| Electrical | 120 V, with a dedicated 15 A circuit recommended. Peak draw is 518 W (6.1 A) cooling and 1,013 W (8.6 A) heating. The user manual gives a typical 350–500 W at 3–5 A while the chiller runs |
| Average power | 130 W over 24 hours holding 40°F, and 260 W holding 100°F. Test conditions aren't stated |
| Sanitation | Ozone generator plus two-stage filtration. The user manual places a quick-swap primary filter in the tank, and a larger XL secondary filter sits in a housing reached through a vent panel |
| Controls and noise | Wi-Fi app (ControlMySpa, per the user manual), touchscreen and programmable lighting. Renu gives 58 dB at about 3 ft from the large grill |
| Dimensions | The body measures 70 L × 33 W × 35 H in. It's 33 in wide at the base and top and about 35.5 in at the widest point of the contoured sides. The tub interior is 40 L × 25 W × 31 D in. The tub weighs 365 lb dry and about 1,155 lb filled with 95 gallons. The user manual gives about 1,165 lb filled. The cut sheet asks for 15 in of clearance at the small vent and 27 in at the large vent. It also asks for 1 to 2 in on the long side for the cord. |
| Materials | Renu doesn't state the shell material, though its warranty page groups the Cold Stoic 3.0 with its plastic tubs. The perimeter has 4 in of HD foam insulation. The version priced here has a California Redwood breath deck, and Pacific Cedar and four composite decks are options. Renu also lists a basic tub lid and a matching step stool, and says the tub is handcrafted in Southern California. |
Before you buy
InstallationRenu recommends a dedicated 120 V, 15 A circuit
Renu recommends a dedicated 120 V, 15 A circuit. The user manual adds that the circuit shouldn't be shared with other devices and calls for grounded 110 V/120 V power. The unit has a GFCI plug. The product page lists a 12 ft cord, but the cut sheet shows both a 12 ft GFCI cord and a 9 ft standard 3-prong cord. No plumbing connection is described. The manual says to fill the tub with a hose to 6 to 8 in below the top and to place it on a level surface in a water-resistant area. It doesn't give a floor-load rating, and the filled tub weighs about 1,155 lb. Delivery is free curbside within the contiguous US, and you have to move the tub off the pallet yourself. It ships in 3 to 5 weeks.
WarrantyCovered components get a 5-year limited warranty from the delivery date
Covered components get a 5-year limited warranty from the delivery date. The water chiller is the exception, at 1 year. The user manual dates coverage from shipment instead. You can add a 4-year extended chiller warranty, for 5 years in total, if you buy it within 364 days of shipment. Its price isn't stated. Coverage is for non-commercial home use in the contiguous US by the original purchaser. Exclusions include water leaks, poor water chemistry, neglected filter care, freezing conditions, power outages, low water flow and misuse. Renu also takes no responsibility for the natural wood of Redwood and Cedar decks. The user manual says the warranty doesn't cover the water filter or the filter housing O-ring. You do most repairs or part replacements yourself. Renu covers parts for covered repairs, and you pay shipping and removal costs. Renu pays approved-provider labor at up to $50 per hour, for a maximum of 2 hours. Rural travel fees aren't covered.
ReturnsYou can return a new cold plunge from a domestic order for any reason within 45 days…
You can return a new cold plunge from a domestic order for any reason within 45 days of delivery. It has to arrive back in good condition, and you pay a 5% restocking fee and shipping costs. Refunds process 3 to 10 business days after receipt. Canceling before shipment costs 5%, and shipped orders can't be canceled. Refurbished, international and bulk (3 or more units) sales are final.
More about this assessment
The Cold Stoic 3.0 is Renu Therapy's hot-and-cold tub, holding 95 gallons at a normal fill. Renu says its 0.5 HP chiller and 1 kW heater set the water anywhere from 37°F to 104°F. The Meterous Black finish with the California Redwood deck listed at $11,399 on Oct 13, 2026, and the insulated spa cover adds $400. Renu recommends a dedicated 120 V, 15 A circuit, and the cut sheet gives a 24-hour average of 130 W holding 40°F. Cooling is slow, at 1.5 to 3°F per hour in the user manual. The chiller is covered for only 1 year, and returns within 45 days cost a 5% restocking fee plus shipping.
Strengths on paper
- Built-in chiller and 1 kW heater cover 37°F to 104°F in one unit
- Renu publishes peak and 24-hour average power draw, so you can estimate running costs
- 5-year limited warranty on covered components other than the chiller, counted from delivery on the warranty page (the user manual says from shipment)
- New tubs can be returned for any reason within 45 days
- Ozone plus two-stage filtration
- Wi-Fi app and touchscreen control
- 4 in of foam insulation
Limitations
- $11,399 list price with no sale price shown, plus $400 for the insulated spa cover
- The chiller is covered for only 1 year
- The extended chiller plan's price isn't stated
- Returns cost a 5% restocking fee plus shipping
- Canceling before shipment also costs 5%
- Slow cooling: at the manual's 1.5 to 3°F per hour, a 30°F drop (say, a 70°F fill to 40°F) works out to roughly 10 to 20 hours
- Curbside delivery only, with a 3 to 5 week lead time
- Renu doesn't state the shell material or any electrical safety listing
What it costs to own.
Adjust the assumptions for your use. Missing costs stay unknown.
PLAN YOUR OWNERSHIP COSTS
What will it cost to own?
Change the assumptions to fit your use. Leave an unknown cost blank. Add water, subscriptions, cleaning, shipping and taxes if they apply. Use average operating power, not the maximum rating.
3-year known subtotal
$12,013.95Incomplete: installation, annual consumables, other annual costs. This is not the full ownership cost.
Energy component: $614.95
Purchase + installation + years × (annual consumables + annual other) + watts/1000 × hours/day × 365 × years × $/kWh. Annualized allowances, not an exact replacement schedule. Excludes taxes, shipping, finance and resale unless entered.Replacement parts & cost assumptions
Recorded recurring parts and refills:
- 12-pack of Secondary XL Filters (SKU PKG-00010): $165. Two XL secondary filters come with the tub. The 12-pack listed at $165 on its own page and on Renu's online store on Oct 13, 2026, with no crossed-out or sale price. That page showed a "Sold Out" label beside "Add To Cart • $165". The pack fits only the XL filter housing (Cold Stoic 3.0, Aurelius, Vero and Siberian Pro). The user manual's maintenance schedule lists the XL (secondary) filter at 6 to 10 weeks and describes cleaning it, not replacing it. Its troubleshooting steps say to change the XL filter if flow stays low. No replacement interval is given, so how long a 12-pack lasts is unknown.
- Primary (in-tank pre-filter): cost not recorded. The product page lists "1 x Re-Usable Primary Filter" and calls the quick-swap filter reusable. The user manual, though, says to replace the in-tank pre-filter (primary) every 2 to 4 weeks, or sooner if ozone bubbles decrease. The product page also shows a $67 12-pack of standard filters. It's listed for other Renu tubs (Standard Siberian, Cold Stoic 2.0 and Classic Stoic), not the Cold Stoic 3.0, so no primary filter price was recorded.
- Purchase is the $11,399 list price on Oct 13, 2026 for the reviewed finish, deck and basic lid. The insulated spa cover would add $400.
- Installation is unknown. No plumbing is needed, and curbside delivery is free within the contiguous US. But Renu recommends a dedicated 120 V, 15 A circuit, and the cost of adding one isn't stated. Moving the 365 lb tub off the pallet and into place is up to you.
- Energy uses the cut sheet's 24-hour average of 130 W while holding 40°F, run around the clock. That's about 3.1 kWh a day, or 1,139 kWh a year. Renu doesn't state the ambient temperature, cover use or test method behind that figure. Holding 100°F averages 260 W. The user manual gives a typical 350 to 500 W while the chiller is running, so real use can differ.
- Annual consumables are unknown. The user manual says to replace the in-tank primary filter every 2 to 4 weeks, though the product page calls it reusable. It says to clean the XL secondary filter every 6 to 10 weeks and change it only if flow stays low. It also says to drain and refill every 3 to 6 months. A 12-pack of XL filters lists at $165. With no stated XL replacement interval and no primary filter price found, filters aren't annualized.
- Renu lists the Wi-Fi app without stating a fee, so other annual costs are left unknown rather than set to zero. The optional extended chiller warranty isn't included because its price isn't stated.
Evidence & sources.
Do cold plunges work? Our evidence review grades the research as Mixed. That grade is about the claim, not about this product.
- Manufacturer claimThe price, options, dimensions, capacity, temperature range, chiller and heater ratings, power figures, filtration, noise and included items all come from Renu Therapy. The sources are its product page, online store listing, cut sheet and user manual. The XL filter price comes from that filter pack's own product page.147 None of it is independent testing of cooling speed, energy use or water quality. The documents disagree on cord length, filled weight and whether the primary filter is reusable. The user manual's typical 350 to 500 W running draw is a different measure from the cut sheet's 24-hour averages. The cut sheet's power table labels no units or voltage. The product page labels the 518 and 1,013 figures as watts, and the 6.1 and 8.6 peak-current figures are read as amps. At 120 V, the cooling figures imply a power factor of about 0.7, which Renu doesn't state.
- Manufacturer claimWarranty length, exclusions, labor limits and the 45-day return terms come from Renu Therapy's warranty page and its cancellation and return policy.56 The warranty page dates coverage from delivery, while the user manual dates it from shipment.
- Manufacturer claimThe product page, cut sheet and user manual cite no electrical safety listing (ETL, UL or CSA), regulatory clearance or independent testing. The manual says only that the equipment "complies with industry norms and meets legal equipment safety requirements."134 Renu makes no medical claim in these documents. A listing missing from them doesn't prove none exists, and certifier databases weren't searched.
- Manufacturer claimThe user manual warns that cold therapy can be dangerous for people with certain health conditions and that prolonged immersion may lead to hypothermia. It says pregnant users should consult a physician first and that the tub isn't designed for anyone under 18.4 These are Renu's safety warnings, not evidence of benefit. Published studies of cold-water immersion weren't reviewed.
Sources (7)
- Cold Stoic 3.0 Renu Therapy · manufacturer · checked Oct 13, 2026
- Cold Stoic 3.0 listing on Renu Therapy's store (finish, deck and lid options) Renu Therapy · manufacturer · data file · checked Oct 13, 2026
- Cold Stoic 3.0 Cutsheet Renu Therapy · manufacturer · checked Oct 13, 2026
- Cold Stoic 3.0 User Manual v0.9 Renu Therapy · manufacturer · checked Oct 13, 2026
- Renu Therapy Cold Plunge Tank Limited Warranty (Home Use Only) Renu Therapy · manufacturer · checked Oct 13, 2026
- Cancellation & Return Policy Renu Therapy · manufacturer · checked Oct 13, 2026
- 12-Pack of Secondary XL Filters for the Cold Stoic 3.0 / Aurelius / Vero / Siberian Pro Renu Therapy · manufacturer · checked Oct 13, 2026
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Compare with this one →About this review. The facts on this page come from manufacturer pages, checked Oct 13, 2026. The sources are listed above.
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