I remember the first time I installed a Rheem 27kW tankless water heater – the job was for a family fed up with inconsistent hot water. They had a traditional tank unit that just wasn’t cutting it for their large household. When I suggested the Rheem 27kW, they were skeptical, but a few months later, they called me back – not for repairs, but to thank me! So, let’s dive deep into this model, and I’ll give you my honest breakdown from installation to long-term use.
Why Choose the Rheem 27kW Tankless Water Heater?
For most homeowners, this tankless model stands out for three major reasons:
- Consistent hot water: No more worrying about running out of hot water mid-shower.
- Energy efficiency: Since it only heats water on demand, your utility bills drop.
- Compact design: Wall-mounted and space-saving, it’s a perfect fit for modern homes.
But those are just the highlights. Let’s get into the nuts and bolts of what it’s really like to own, install, and use this system.
Key Features Breakdown
| Feature | Details |
|---|---|
| Power Output | 27kW |
| Max GPM (Gallons per Minute) | 6.6 GPM in warm climates |
| Temperature Range | 80°F to 140°F |
| Energy Efficiency | 99.8% |
| Dimensions | 18.25 x 14.5 x 3.5 inches |
| Digital Temperature Control | Yes, with ±1°F accuracy |
| Warranty | 5 years (heat exchanger), 1 year (parts) |
Installation Experience: A DIY Challenge or Smooth Sailing?
When I installed this for the first time, it was clear this isn’t just a plug-and-play job. Here are some things to watch out for:
1. Electric Requirements
- Dedicated Circuit: You’ll need at least three 40-amp double-pole circuit breakers. Many homes aren’t wired for that level of load right off the bat. I had to upgrade the electrical panel for that family, which added to the time and cost.
- Wiring: This baby needs some serious wiring. You’ll use 8-gauge wires, which may require rerouting depending on your layout.
2. Water Connections
- You’ll need to make sure you have 3/4″ NPT fittings, so double-check your plumbing setup. If you’re replacing a traditional tank, you might need to make some adjustments.
3. Ventilation? Not Needed!
- This was a pleasant surprise. Since the Rheem 27kW is electric, no need for venting like with gas units. This saves both installation space and labor time.
Tip: If you’re confident in basic plumbing and electrical work, you can take this on. However, if you’re unsure, get professional help for the electrical aspect.
Performance: Does It Deliver?
This model is designed for medium to large homes with 2-3 bathrooms. Here’s how it performs across different areas:
Water Flow & Temperature Consistency
- In warm climates (with incoming water temps around 70°F), you can expect up to 6.6 GPM. That’s enough to run two showers and a dishwasher simultaneously without any issues.
- In colder climates where water temps drop, the GPM decreases to around 3 GPM. This still covers two showers or one shower and a sink at a time.
I installed one in a northern climate house, and while the family could run one shower comfortably, running a second fixture caused a slight drop in temperature. So if you live in a colder region, plan accordingly for the lower GPM.
Energy Efficiency
- This unit is 99.8% energy efficient. Unlike gas models, there’s virtually no standby heat loss because water is only heated when needed. This translates into noticeable savings on electric bills.
Temperature Control
- The digital thermostat allows you to set precise temperatures with 1°F accuracy, which is fantastic if you like customizing your shower temp or have different needs across family members.
Maintenance and Long-Term Use
After a year of use, I did a follow-up with that same family. Here’s what I’ve found out about long-term care:
Descaling
- Hard water can build up inside the heat exchanger. It’s recommended to flush the system once a year. If you’re in a hard-water area, you’ll want to install a pre-filter to extend the unit’s life.
Warranty and Support
- Rheem offers a 5-year warranty on the heat exchanger and 1 year on parts. The company has a solid reputation, and replacement parts are fairly easy to find.
Pros and Cons of the Rheem 27kW Tankless Water Heater
Pros:
- Endless hot water: Perfect for large households or those who use hot water frequently.
- Compact design: Saves significant space compared to bulky tank models.
- Energy-efficient: The 99.8% efficiency rate will reduce your electricity costs.
- No venting required: A huge plus if you’re switching from gas to electric.
Cons:
- Electrical upgrades: Many homes need electrical panel upgrades to accommodate the 27kW system, which can get expensive.
- Cold climate limitations: If you’re in a cold region, expect lower GPM, which can limit simultaneous water usage.
- Initial cost: The upfront cost, including installation, is higher than traditional tanks, but long-term savings help offset that.
Is It Right for You?
If you have a larger home with multiple bathrooms and live in a warmer climate, this unit is a no-brainer. Even in colder climates, it performs well, but you’ll need to be mindful of water flow limitations. Also, be prepared for some initial installation costs, especially if electrical upgrades are necessary.
Final Word: The Rheem 27kW tankless water heater is a powerful, reliable, and efficient choice, but make sure your home’s electrical system can handle it, and be realistic about your hot water needs depending on your climate. After all, I’ve seen firsthand how happy families can be when their hot water woes are finally solved!