Description
If you are building or remodeling a steam shower, the generator is the heart of the system, and the Mr. Steam MS iTempo R09C1AA is designed to deliver it reliably. Rated at 9 kW and sized for steam rooms up to about 257 cubic feet under standard construction, it ships as a complete package with the iTempo Round control so you can plan the whole system at once.
Mr. Steam MS iTempo packages pair the MS-R (5-9 kW) residential steam generator with the iTempo digital control and a matching Aroma Designer SteamHead; the accessories version adds SteamLinx app control, AutoFlush and a condensation pan. In this guide we cover how the Mr. Steam generator works, how to size it for your room, what the electrical and plumbing requirements look like, and how to keep it running for years. Everything is written in plain language for homeowners, designers and the contractors who install these systems every day.
Quick Answer: What Is the Mr. Steam MS iTempo R09C1AA?
The Mr. Steam MS iTempo R09C1AA is a 9 kW electric steam generator that produces roughly 30,708 BTU per hour of steam energy, rated for steam rooms up to about 257 cu ft. It runs on 240V 1-Phase and draws 38 A at 240V. It installs outside the shower, typically in a vanity, closet, attic or basement, and sends steam through a steamhead mounted low on the shower wall.
Mr. Steam MS iTempo R09C1AA Specifications
| Brand | Mr. Steam |
|---|---|
| Equipment Type | Steam Shower Generator Package |
| Model Number | R09C1AA |
| Product Line | MS iTempo |
| Voltage / Phase | 240V 1-Phase |
| Amperage | 38 A at 240V |
| Unit Dimensions (W x D x H) | 14.5 in x 6.75 in x 14.75 in |
| Unit Weight | 25 lb |
| Shipping Weight | 27 lb |
| Warranty | Limited lifetime on generator parts; 2 years limited on control, steamhead and accessories |
| Certifications | cULus Listed, CE, ASME safety valve |
| Capacity (kW) | 9 |
| Room Size (cu ft) | 257 |
| Control Type | iTempo Round |
| Included Components | generator, iTempo control, Aroma Designer SteamHead, SteamLinx module, AutoFlush valve, condensation pan |
| Compatible With | SteamLinx / MrSteam Controls App, AutoFlush, AromaSteam, ChromaSteam, Express Steam (factory option) |
| Number of Steamheads | 1 |
| Outlets / Ports | 3/8 in NPT water supply, 3/4 in NPT steam outlet, 3/4 in NPT safety valve, 3/4 in NPT steamhead, 1/2 in NPT drain |
| Aromatherapy | Yes (Aroma Designer SteamHead oil well) |
Key Features of the Mr. Steam MS iTempo R09C1AA
- MS400R generator rated 9 kW at 240V single phase, 38 A draw
- Sized for 162-257 cu ft of adjusted room volume (ceramic/porcelain tile on cement board; add 50% for natural stone/glass block/concrete, subtract 40% for acrylic/fiberglass, add 15% per foot of ceiling over 8 ft)
- iTempo control: solid brass round or square cover, digital display, programmable temperature, soft-touch keypad, low-voltage operation
- Stainless steel tank with industrial large-diameter serviceable heating element and electronic water-level control
- 60-minute electronic countdown shutdown with 75-minute safety backup; built-in 24V low-voltage control; ASME safety valve
- Installs up to 60 ft from the steam room (closet, vanity, heated attic, basement); zero clearance to combustibles
- Accessory kit adds SteamLinx (smartphone control via MrSteam Controls App), AutoFlush (drains the tank about 2 hours after each use) and a condensation pan
How a Steam Shower Generator Works
A steam generator is a compact electric boiler. When you start a session at the control, a fill valve lets water into a sealed stainless steel tank. A heating element brings that water to a boil, and the steam travels through a copper or brass steam line to the steamhead inside your shower. A water-level sensor keeps the tank topped up during the session, and a temperature sensor at the control cycles the element so the room stays at the temperature you selected instead of continuing to heat.
Because the generator lives outside the wet area, the only things inside the shower are the control and the steamhead. That keeps the enclosure clean-looking and makes service easy: a technician can reach the generator without removing tile. Most modern generators reach full steam in a few minutes and include a safety timer that shuts off steam at the end of the session, plus a pressure-relief or safety valve that protects the tank.
How to Size a Steam Generator for Your Shower
Steam generators are sized by the volume of the room, not the floor area. Measure the inside length, width and ceiling height of the enclosure in feet and multiply them together to get cubic feet. Then adjust for the materials and layout:
- Wall and ceiling materials: ceramic or porcelain tile on cement board is the baseline. Natural stone, marble, glass block, concrete and large glass panels absorb more heat, and manufacturers increase the required capacity for them, in some charts by as much as 50 percent. Acrylic or fiberglass enclosures need less.
- Ceiling height: ceilings above 8 feet add volume and usually call for a larger unit.
- Exterior walls and windows: cold outside walls pull heat out of the room, which matters most in northern climates.
- Distance: long steam lines lose heat, so keep the generator as close to the shower as the manufacturer allows.
This generator is rated for steam rooms up to about 257 cubic feet under standard construction. The table below shows how a few common enclosure sizes compare, first with standard tile and then with a heat-absorbing finish such as natural stone (using a 50 percent adjustment as an example).
| Enclosure (L x W x H) | Cubic feet | Standard tile | Natural stone (+50%) |
|---|---|---|---|
| 4 ft x 4 ft x 8 ft | 128 | Within rating | Within rating |
| 4 ft x 6 ft x 8 ft | 192 | Within rating | Larger generator needed |
| 5 ft x 7 ft x 8 ft | 280 | Larger generator needed | Larger generator needed |
| 6 ft x 8 ft x 9 ft | 432 | Larger generator needed | Larger generator needed |
If your adjusted volume lands close to the limit, step up to the next size. An undersized generator struggles to reach temperature, while a correctly sized unit heats the room quickly and cycles normally. Always confirm the final choice with the manufacturer's sizing chart for your exact materials.
Good, Better, Best: Where the Mr. Steam MS iTempo R09C1AA Fits
At HVAC365 we organize every category into a simple Good, Better, Best framework so you can compare options without wading through jargon. Within our steam shower generator lineup, this model sits in the Better tier: Enhanced comfort and smarter control.
The Better tier steps up efficiency and adds smarter control. It balances up-front cost with lower operating cost and more convenience, which is why property managers and owners who plan to keep their equipment for years often land here.
Not sure the Better tier is right for you? Compare it with the Good and Best options in the same category. Whatever tier you choose, the equipment is brand new and covered by the full manufacturer warranty, and our team is here to help you weigh features against budget.
Installation, Electrical and Plumbing Requirements
A steam generator needs a dedicated electrical circuit (240V 1-Phase, 38 A at 240V), a cold or hot water supply with a shut-off valve, a steam line to the shower, and a drain or safe discharge point for the safety valve and tank drain. Professional installation is recommended: a licensed electrician should size the breaker and wire according to the manufacturer's instructions and local code, and a licensed plumber should handle the water, steam and drain connections.
The enclosure itself matters just as much as the generator. A steam shower needs walls and a ceiling that are fully waterproof and vapor-tight, a door that closes tightly and reaches close to the ceiling, and a ceiling that slopes slightly so condensation runs down the walls instead of dripping on you. Mount the steamhead low on the wall, away from seating and feet, and place the control where it is easy to reach from a seated position. Plan the generator location so it is accessible for service and within the maximum steam-line distance in the installation manual.
Connection sizes for this model: 3/8 in NPT water supply, 3/4 in NPT steam outlet, 3/4 in NPT safety valve, 3/4 in NPT steamhead, 1/2 in NPT drain.
Maintenance and Care
Steam generators are low-maintenance, but water quality is the biggest factor in how long they last. Minerals in hard water collect in the tank as scale, which insulates the element and shortens its life. To keep your generator healthy:
- Use the automatic drain or flush feature if your model has one, so the tank empties after each session.
- In hard-water areas, consider a water softener or follow the manufacturer's descaling schedule.
- Wipe down the steamhead and keep it clear; never cover it, because it gets hot during use.
- Run the bathroom exhaust fan after a session to clear moisture from the rest of the room.
- Have a technician inspect the safety valve, water-level probe and fittings during routine service.
Regional and Climate Considerations
Where you live affects both sizing and upkeep. In colder northern states, steam rooms built on exterior walls or under unheated attics lose heat faster, so insulation and a slightly larger generator pay off. In the Southwest, Florida, Texas and much of the Midwest, hard water is common, which makes automatic flushing and water treatment especially valuable. In hot, humid southern climates, good bathroom ventilation after each session keeps moisture from spreading to the rest of the home. Wherever you are, our team can help you account for local conditions before you order.
What's Included and Compatibility
- MS400R 9 kW steam generator (MS-R series) with installation and operation manual
- iTempo control, round solid brass cover, with 30 ft control cable and silicone sealant
- Aroma Designer SteamHead, round (model 104515), matching finish
- SteamLinx module (generator and router modules, Ethernet cord, power adapter) for the MrSteam Controls App
- AutoFlush automatic drain valve with cord
- Condensation (drip) pan, 25 in x 9 in x 1.5 in (model 103867)
Compatible with: SteamLinx / MrSteam Controls App, AutoFlush, AromaSteam, ChromaSteam, Express Steam (factory option).
Manufacturer warranty: Limited lifetime on generator parts; 2 years limited on control, steamhead and accessories.
Ideal for:
- Residential steam showers up to 257 cu ft adjusted volume (tile on cement board)
- New-construction or remodel steam showers needing a remote-mounted generator (closet, vanity, heated attic, basement within 60 ft)
- Projects requiring a dedicated 240V single-phase circuit
Built for Homeowners, Contractors and Property Managers
- Homeowners: use our sizing guidance above, measure your enclosure, and send us the dimensions and finish materials. We will confirm the right generator before you buy.
- Contractors and installers: order in two clicks, follow every shipment with live tracking, and reorder common parts from the HVAC365 Contractor Portal. We know the labor shortage is real, so we focus on getting the right part to the job the first time.
- Property managers: manage equipment for multiple properties from one dashboard and book a strategy call with our team to standardize models, plan replacements and control maintenance costs.
Why Buy from HVAC365?
HVAC365 is your everyday source for home comfort products. Our mission is to make buying equipment simple, transparent and accessible. Instead of a wall of part numbers, you get clear specifications, honest guidance and technology-driven tools that help you choose with confidence. Compared with traditional online wholesalers, we add AI-guided product discovery, side-by-side selection tools and help coordinating service, so you are never left guessing about compatibility or installation.
- Brand-new equipment with the full manufacturer warranty
- Clear, published specifications and plain-language explanations
- Fast shipping with tracking from order to delivery
- Real people who answer questions before and after the sale
- Ask about financing options to spread the cost of larger projects
We believe great home comfort should be accessible to everyone. Our team is happy to help with large-print spec summaries, phone-based ordering, or any other accommodation that makes shopping easier for you.
Frequently Asked Questions About the Mr. Steam MS iTempo R09C1AA
What size steam shower can the Mr. Steam MS iTempo R09C1AA handle?
It is rated for about 257 cubic feet under standard tile construction. Rooms finished in natural stone, glass or concrete, or with tall ceilings, need extra capacity, so calculate your adjusted volume before ordering.
Does a steam generator need a dedicated circuit?
Yes. Steam generators draw significant current (38 A at 240V) and should be on their own dedicated circuit sized by a licensed electrician per the installation manual and local code.
Where is the steam generator installed?
Outside the shower in a dry, accessible, ventilated location such as a vanity, closet, attic or basement, within the maximum steam-line distance listed in the manual. Only the control and steamhead go inside the shower.
How long does it take to heat up?
Most correctly sized residential generators produce steam within a few minutes and bring the room to a comfortable temperature shortly after. Heat-absorbing materials, high ceilings and long steam lines add time.
How long should a steam session last?
Many people enjoy sessions of about 10 to 20 minutes. Drink water before and after, and talk to your doctor before using steam if you are pregnant or have heart, blood-pressure or other health conditions.
Can I add aromatherapy or music?
Yes. Yes (Aroma Designer SteamHead oil well). Many systems support aromatherapy steamheads, lighting and speakers as add-ons. Check the compatibility list above or ask our team which accessories work with this generator.
What warranty does it have?
Limited lifetime on generator parts; 2 years limited on control, steamhead and accessories.
Ready to order? Add the Mr. Steam MS iTempo R09C1AA to your cart, or contact the HVAC365 team for help confirming sizing and compatibility. We are here to make your project simple from start to finish.
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