Tankless Water Heaters: Limitless On-Demand Hot Water

Wait less, waste less and save more.

With a tankless water heater, your home's cold water is heated only when you need it, and it stays hot until you're done using it. This results in a limitless hot water supply and little to no wasted energy usage.

Here’s How They Work

Tankless water heaters can work with both natural gas and propane heat sources.

• Flame ignites and heats two heat exchangers
• Water preheats as it passes through the secondary heat exchanger
• Water continues to heat to desired temperature as it passes through stainless steel primary heat exchanger
• Water exits the unit and travels to the water fixture where it is needed
• Flame output adjusts as needed to maintain water temperature during use
• With usage complete, the flame turns off and water stops flowing

Benefits of Tankless Water Heaters

Never Run Out of Hot Water: With a tankless water heater, you’ll never have to choose between taking a piping hot shower, doing a load of laundry, or running the dishwasher. Hot water is always available.

Better Value Than a Tank: Tankless water heaters last up to twice as long, have twice the warranty, and save energy as they only heat water when it is needed. They Rinnai line of RX series units are all EnergyStar certified with a UEF rating of .97 or .98.

Save Valuable Space: Small and mighty, the suitcase-sized wall units fit in tight, discreet spaces, freeing up more usable living area in your home. No more storing large quantities of water that could potentially leak on your floor. Also, parts are usually replaceable, rather than replacing the entire unit.

Technology to Improve Your Lifestyle: Select models have the Rinnai Smart-Circ™ Intelligent Recirculation™ that learns your hot water usage pattern and schedules your recirculation accordingly, providing you with hot water faster and when you need it. With the additional purchase of an RWM200 wireless module (sold separately, compatible with most condensing models), you can integrate it into your smart home technology for greater control and have on-demand hot water in seconds.

Reliability You Can Count On: Every Rinnai tankless water heater is individually tested for quality before shipping. Unlike many competitors, Rinnai makes the vast majority of our key components, allowing for consistent control of quality. That’s why more consumers and businesses choose Rinnai over any other tankless brand.

Ready to Upgrade Your Water Heater?

Don’t wait until your system fails and you’re left with cold showers. Take a few minutes today to explore your options.

👉 Start your free, instant water heater quote here: Denommee Water Heater Quotes

Or call/text our team at 978-649-8886 to schedule a no-cost in-home consultation.

From traditional tank water heaters to tankless on-demand systems to heat pump hybrids with rebates, Denommee is your trusted local expert for reliable hot water solutions.

Rinnai + Denommee = Total Confidence

Get endless on-demand hot water, space savings, eco-efficiency and peace of mind from the world’s most reliable tankless gas water heater brand. Whether you need a residential water heater or commercial water heater, you can trust the #1 selling gas tankless water heating brand in North America. Enjoy the total confidence that comes with 30 years of innovation, support and integrity knowing a Rinnai® tankless water heater will meet your needs. It’s time to expect more because you deserve it.

Denommee Plumbing, HVAC & Electric: Four Generations of Experience. 

We have been providing legendary plumbing heating system installation and service to our valued customers across Massachusetts and southern New Hampshire for well over twenty years. As your local Rinnai VIP contractor, we are your expert resource for installation and service of these top-in-class tankless water heaters. Serving customers in the Tyngsborough, MA area and surrounding towns, as well as the greater Burlington, MA area and surrounding towns, Denommee Plumbing, HVAC & Electric is are the plumbers to call upon when searching for plumbers near me.

We have the licensed experts and technicians, along with the right products, equipment and solutions to serve all your home or business’s plumbing, heating and cooling needs. We service nearly all existing types and brands of plumbing and HVAC systems. Our service is legendary—we have decades of experience getting the job done, for the right price. 

Endless Hot Water on Demand

Enjoy all the hot water you want, when you want it. With a Rinnai tankless, you’ll put an end to rationing water. Never choose between taking a shower or doing dishes. When demand is high, a traditional tank water heater can run out and leave you or your family in the cold. A tankless gas water heater heats water as it goes through the pipes, giving you an endless hot water supply.

Save Money, Energy and Space

Rinnai tankless water heaters are more energy efficient with lower CO2 emissions compared to tank water heaters. A tank water heater may heat and reheat water even when you’re not at home-wasting money and energy. Tankless only heat when you need it. Gallon for gallon you will spend less heating your hot water. Your water heater need not be a behemoth taking up valuable living space. A Rinnai tankless is only the size of a small suitcase and can be mounted in an attic, basement, garage or even outside, meaning more space for living and less for heating hot water.

Reliability for the Long Haul

Rinnai tankless water heaters are designed, engineered and built for the long haul. They can last up to two times as long as a traditional tank water heater. When purchased from us, your local Rinnai authorized dealer your Rinnai comes with a generous warranty and the backing of a company that knows how to install and maintain your tankless to ensure you enjoy maximum performance and longevity from your water heater.

Denommee Plumbing, Heating & Cooling: Installing working works of art

Denommee Plumbing, HVAC & Electric is renowned for quality craftsmanship in plumbing and HVAC system installations. Attention to detail, along with clean and careful work are hallmarks of our team of professional installers and service technicians. If you’re in the Tyngsborough, Burlington, or surrounding areas and are interested in learning more about tankless water heaters, don’t hesitate to give us a call. Our expert technicians will provide you with an honest, detailed inspection of your plumbing system's water heating system needs, offer recommendations for ensuring your home has plenty of warm water and that your water heater safely operates a peak capacity and efficiently for years to come. Book your tankless water heater services instantly through text! Simply text "Tankless Water Heater" to 8572269140.

NEW: Free Instant Water Heater Quotes from Denommee

We know homeowners want clear, upfront pricing—without waiting days for callbacks or sales appointments. That’s why Denommee has partnered with Contractor Commerce to launch our new online Water Heater Journeys quote tool.

Here’s how it works:

1. Visit our site: Denommee’s Water Heater Quotes.

2. Answer a few simple questions about your home and water heating needs.

3. Instantly see pricing for multiple water heater options—traditional tank, tankless, or heat pump.

✅ No obligation. The quotes are informational only—there’s no contract until you decide.
✅ No pressure. Explore options at your own pace, from the comfort of your home.
✅ Next step support. If you’d like to move forward, you can book a no-cost, in-home appointment with one of Denommee’s licensed plumbing pros to confirm details and finalize your project.

Denommee’s Unique Value for Homeowners

Choosing the right contractor is just as important as choosing the right water heater. Here’s why homeowners across Massachusetts and southern New Hampshire trust Denommee:

• Expertise in all water heater types – tank, tankless, and heat pump.

• Licensed, in-house plumbers and electricians – no delays waiting on subcontractors.

• Flat-rate pricing – no hidden charges, ever.

• Peace of Mind Service Memberships – seasonal maintenance, priority service, and discounted repairs.

• Trusted local service – serving Billerica, Acton, Groton, Chelmsford, Nashua, and surrounding towns.

Whether it’s a straightforward tank replacement or a high-efficiency hybrid system upgrade with rebates, Denommee has the team, training, and tools to get it done right.

Why Professional Installation Matters

A water heater isn’t a DIY project. Proper installation ensures:

• Code compliance – permits, venting, and safety checks.

• Warranty protection – most manufacturers require professional installation.

• Efficiency and safety – improper connections can cause leaks, scalding, or electrical hazards.

Denommee handles everything—from removal of your old system to permitting, installation, and clean-up—so you can relax knowing the job is done safely and correctly.

Protect Your Investment with Peace of Mind Membership

Every water heater needs maintenance to maximize its lifespan and efficiency. Denommee offers Peace of Mind Memberships that include:

• Annual plumbing, HVAC, and electrical tune-ups

• Priority scheduling for emergencies

• Discounts on repairs and replacements

• Flat-rate service with no surprises

It’s the easiest way to protect your new investment while keeping your whole home running smoothly.

Peace of Mind Membership Benefits for Plumbing

Our exclusive Peace of Mind Service Program helps prevent plumbing problems before they start. Members enjoy:

• Annual whole-home plumbing assessments

• Waived service dispatch fees

• Priority scheduling

• Discounts on toilet repairs, upgrades, and drain services

• $100/year loyalty credits for plumbing improvements (up to $500 value)

If your home has kids, multiple bathrooms, or an aging plumbing system, this plan is the perfect way to ensure worry-free operation.

Benefits of Being a Peace of Mind Member

1. Deep Discounts on Vital Home Maintenances

Preventative care is the best way to avoid expensive, unexpected repairs. As a member, you'll receive discounted rates on:

• Drain clearing and drain camera inspections

• Maintenance for all types of gas, oil, and electric HVAC systems

• Water heater flushing and maintenance

• Circuit breaker panel inspections and tune-ups

2. Whole-Home System Inspections

Every year, Denommee’s expert team will perform a comprehensive inspection of your:

• Plumbing system (including valve tagging important shutoffs)

• Heating and cooling system (including combustion analysis for gas and oil equipment)

• Electrical system (including fire, smoke, and CO alarm checks)

We provide full documentation of findings to help you identify and prioritize potential issues before they become urgent.

3. Loyalty Credits Toward Upgrades

Every year you remain a member, you earn a $100 Loyalty Credit (up to $1000) toward plumbing, HVAC, electrical, or drainage system replacements and upgrades. It's a valuable way to save on major improvements over time.

4. Priority Service and Fast Response

• Front-of-the-line scheduling

• 24 hours or less repair response time

• Dedicated member-only phone line

• Waived dispatch fees during regular service hours

Your peace of mind is our priority, and our team is always ready to help take the stress out of home repairs and maintenance.

5. Increased Home Value

Paid memberships are fully transferable if you sell your home, making your property even more attractive to prospective buyers.

How Membership Helps Avoid Costly Breakdowns

Breakdowns happen, but with regular, proactive maintenance visits included in your membership, Denommee's professional team helps you stay ahead of system failures.

• We get to know your home and your unique mechanical systems.

• We catch small issues before they cause major repairs.

• We optimize system performance for efficiency, comfort, and longevity.

• We help reduce emergency calls for overnight, weekend, or holiday repairs.

Our Peace of Mind Service Program is about more than maintenance — it's about truly protecting your home, family, and finances.

🔗 Learn More: https://www.denommeeplumbing.com/residential-service-programs

CLICK TO REQUEST YOUR MEMBERSHIP TODAY

Ready to Upgrade Your Water Heater?

Don’t wait until your system fails and you’re left with cold showers. Take a few minutes today to explore your options.

👉 Start your free, instant water heater quote here: Denommee Water Heater Quotes

Or call/text our team at 978-649-8886 to schedule a no-cost in-home consultation.

From traditional tank water heaters to tankless on-demand systems to heat pump hybrids with rebates, Denommee is your trusted local expert for reliable hot water solutions.