Best Commercial Electric Tankless Water Heaters for On‑Demand Hot Water
When choosing a compact, on‑demand electric tankless water heater for commercial or high-usage settings, look for models that deliver reliable flow, solid temperature control, and robust electrical requirements. This guide highlights five solid options suitable for small to mid-sized commercial spaces, offices, or multi‑bath facilities that need continuous hot water without a bulky storage tank. Each product section notes who it’s best for and a key limitation to consider. A quick comparison table is provided in the introduction to help you decide at a glance.
Quick product comparison
| Product | Best For | |
|---|---|---|
| WINTEMP 36kW | Mid‑size homes or small commercial spaces | High output (up to 8.7 GPM) |
| APUS 27kW | Space‑constrained installations with moderate demand | Memory function and LED display |
| Orbek 18kW | Two to three fixtures, compact setups | Efficient, quick hot water |
| Eemax EEM24027 | Projects needing reliable continuous output | Simple 3 × 40A wiring |
| Rheem 18kW | Smaller commercial or office bathrooms | Self‑modulating, LED thermostat |
WINTEMP 36kW Tankless Electric Water Heater
The WINTEMP 36kW tankless model is designed for whole-house supply in moderate to larger spaces, offering up to 8.7 GPM. It uses self‑modulating technology to adjust power in real time for stable temperatures and energy efficiency. This unit is best for facilities with a substantial hot water load, such as small commercial offices or multi‑bath setups. A potential limitation is the required electrical service: 300A recommended with multiple high‑amperage breakers, which may demand electrical upgrades for installation.
APUS 27kW Tankless Water Heater
The APUS 27kW unit delivers up to 6.5 GPM with a compact footprint, making it suitable for whole‑home or multi‑fixture use in small commercial spaces. It features a memory function and an LED display for precise temperature control, plus self‑modulating technology to optimize energy use. Choose this if you need reliable on‑demand hot water for multiple points of use without a large installation footprint. A limitation is the need for three 40‑amp breakers and a robust electrical run, which should be planned in advance.
Orbek 18kW Tankless Water Heater
The Orbek 18kW model is compact and suitable for two to three fixtures at moderate demand, delivering up to 4.17 GPM. It emphasizes energy efficiency through water‑electricity separation and fast hot water delivery. Best for smaller commercial spaces or retrofit projects where space is at a premium. A potential drawback is that it may require careful electrical planning to meet simultaneous usage scenarios; ensure your electrical panel can accommodate the load.
Rheem 18kW 240V Tankless Electric Water Heater
The Rheem 18kW model uses external digital thermostatic control with LED display and self‑modulation to match hot water demand. It’s a straightforward option for smaller commercial setups or offices with modest hot water needs, offering reliable hot water without a storage tank. One limitation is that maximum flow is around 4.4 GPM, which may be insufficient for several simultaneous uses in busier environments.
Rheem 11kW 240V Tankless Electric Water Heater
The 11kW Rheem unit offers an adjustable temperature display with self‑modulating power control, delivering up to 2.68 GPM. It’s best for very small setups or point‑of‑use applications where demand is light and space is at a premium. If your facility has higher simultaneous hot water needs, this model may require pairing with another unit or selecting a higher‑capacity option.
WINTEMP 27kW Tankless Electric Water Heater
The WINTEMP 27kW unit provides up to 6.5 GPM and requires a 200A service with three 40A breakers. It’s designed for multi‑bath homes or small commercial spaces that need steady hot water across multiple fixtures. It emphasizes stable temperature control and energy savings through self‑modulation. A limitation to consider is electrical compatibility and whether your site can support the recommended service upgrade.
Buying Guide
What size do I need?
Calculate peak hot water demand by listing fixtures that may run simultaneously (shower, sink, dishwasher, etc.). Choose a unit that can deliver the total GPM at the set outlet temperature. If you expect high concurrent usage, consider higher kW models or multiple units in parallel.
What about electrical service?
Most tankless electric heaters require substantial electrical service and dedicated breakers. Verify supply capacity (amps), breaker count, and wire gauge. In some cases, you may need a service upgrade to support a 3 × 40A or 3 × 60A configuration depending on the model and installation footprint.
Where should I install it?
Tankless heaters are compact, but placement matters. Install close to the point of use to minimize heat loss in long runs. Ensure proper venting or drainage as required by the model and local codes. Consider a dedicated circuit and a clean electrical run for reliability in a commercial setting.
What about energy efficiency?
Self‑modulating technology helps reduce energy usage by adjusting power to match real‑time demand. This feature is valuable in commercial environments where usage can vary widely throughout the day. Look for models with precise temperature control and a reliable display for operators.
Important installation notes
- Confirm water inlet/outlet connections are 3/4″ NPT or per model specification.
- Plan for the appropriate gauge wiring (often AWG 6 or 8) and breaker arrangement.
- Consult a licensed electrician to review electrical compatibility and safety compliance.
FAQ
- What is the typical flow rate I should expect from a residential/small commercial tankless heater?
Most units in this guide deliver between 2.5 and 8.7 GPM depending on model and inlet water temperature.
- Can these units be installed in parallel for higher capacity?
Yes, some models support parallel installation, which can increase total available GPM. Check the manufacturer’s guidance for wiring and control requirements.
- Do all units require a power upgrade?
Many units require substantial electrical service (up to 300A in some cases). An electrical assessment is essential before purchase.
- Is self‑modulating technology better than fixed output?
Self‑modulating systems adapt to demand, improving energy efficiency and temperature stability, which is advantageous in variable usage environments.
- What maintenance is typical for tankless electric heaters?
Regular inspection of electrical connections and periodic flushing of mineral buildup can extend life and maintain performance. Follow the manufacturer’s maintenance schedule.