Northern VA Tankless Water Heater Installs & Repair
We do tankless water heater installation and repair in Northern Virginia, including system sizing, setup, and ongoing service. We make sure your system is properly configured so it performs the way it should day to day.
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Tankless Systems Installed and Serviced the Right Way
If your tankless or on-demand water heater isn’t keeping up—or you’re upgrading from a traditional tank—it usually comes down to how the system was sized, installed, or how it’s currently operating. We pinpoint what’s actually causing the issue—whether it’s sizing, setup, or the unit itself—and correct it so your system runs the way it should.
Across Northern Virginia, we see this play out in different ways. Older homes often weren’t set up for tankless, which can lead to undersized gas lines or venting issues. Newer homes tend to have higher hot water demand, where systems fall short if they’re not sized for simultaneous use. On top of that, local water conditions can lead to scale buildup that affects performance over time.
Why Homeowners Choose HVAC & Plumbing Unlimited for Tankless Systems
At HVAC & Plumbing Unlimited, the focus is on getting that right from the start and giving you clear answers along the way. Whether you’re installing a new system or dealing with performance issues, the goal is straightforward—make sure it works the way it’s supposed to without overcomplicating it.
✔ Clear, straightforward recommendations based on your home and usage
✔ Systems sized and set up properly, no one-size-fits-all installs
✔ Experience working with gas tankless systems across different home setups
✔ Repairs that address the cause of the issue, not just the symptom
✔ Safe, code-conscious work around gas lines and venting
✔ One team handling both plumbing & system-related work without handoffs
It’s not about pushing a system—it’s about making sure the one you have, or the one you’re installing, is set up to perform reliably over time.
Tankless Water Heater Services We Offer
Tankless systems require a different approach than traditional water heaters. We handle installation, repair, and ongoing service so your system performs the way it should.
Tankless Installation & Replacement
Upgrading to tankless or replacing an older unit requires proper sizing, gas line capacity, and venting. We install systems based on your home’s demand so you get consistent performance without running into capacity issues.
Tankless Water Heater Repair
Error codes, fluctuating temperatures, or no hot water—tankless systems can fail for a range of reasons. We diagnose the issue and fix the root cause so the system runs reliably again.
Tankless Maintenance & Flushing
Regular flushing and system checks help prevent scale buildup and keep efficiency where it should be. This is especially important in Northern Virginia where water quality can impact system performance over time.
Gas Line & System Setup Adjustments
Tankless systems often require updates to gas lines or venting to operate properly. We make sure everything is set up safely and aligned with the system requirements.
Call us at (571) 360-4520 to schedule an appointment.
Serving Homeowners Across Northern Virginia
HVAC & Plumbing Unlimited provides tankless water heater installation, repair, and maintenance throughout Northern Virginia. We work in a wide range of homes—from older properties that require retrofits to newer builds with higher hot water demand—so the approach is always based on your setup.
We regularly service areas including Alexandria, Arlington, Fairfax, Springfield, Burke, Annandale, Reston, Herndon, Centreville, Chantilly, Woodbridge, Manassas, Falls Church, and Ashburn.
We Service All Types of Tankless Water Heaters
Tankless systems vary by fuel type, design, and application. HVAC & Plumbing Unlimited works across all major tankless configurations, making sure each system is installed, serviced, and maintained based on its specific requirements.
We work on gas tankless systems, condensing and non-condensing units, whole-home and point-of-use setups, and most major brands.
How to Choose the Right Tankless Water Heater
Choosing the right tankless system comes down to one thing—making sure it can keep up with how your home uses hot water. Most issues homeowners run into with tankless systems come from improper sizing or setup, not the unit itself.
Hot water demand (flow rate + capacity)
Tankless systems are sized by flow rate (GPM) and heating capacity (BTU). This determines how many fixtures can run at the same time without losing temperature.
If the system is undersized, you’ll notice it right away—showers turning cold when another fixture is used or inconsistent temperatures throughout the house.
Gas vs. electric systems
- Gas tankless → higher output (up to ~199,000 BTU), better for whole-home use where multiple fixtures run at once
- Electric tankless → lower capacity, typically used for smaller homes or single-point applications
Condensing vs. non-condensing
- Condensing → higher efficiency, better long-term performance and operating cost
- Non-condensing → lower upfront cost, but less efficient over time
Installation requirements
This is where most problems happen. Proper setup matters just as much as the unit:
- Proper gas line sizing to handle demand
- Correct venting for safe operation
- Electrical support for ignition and controls
If these aren’t addressed during installation, the system won’t perform the way it should—no matter how good the unit is.
Taken together, these factors determine whether your tankless system can actually keep up with your home’s hot water demand. When everything is matched correctly—flow rate, BTU capacity, system type, and installation—you shouldn’t have to think about it. You can run multiple fixtures, temperatures stay consistent, and the system performs the way it’s supposed to.
If something feels off—temperature drops, inconsistent hot water, or the system struggling during peak use—it’s usually not the brand. It’s a sign the system wasn’t sized or set up correctly. A properly configured tankless water heater should handle your daily usage without hesitation. If it doesn’t, it’s worth taking a closer look at how the system was selected and installed.
Call (571) 360-4520 or book online for water heater service.
Tankless Brands We Work With
We install and service most major tankless brands, including:
- Rinnai
- Navien
- Rheem
- Noritz
- A. O. Smith
Each brand offers different strengths in efficiency, output, and system design—the key is choosing the right unit for your home and installing it correctly.
FAQs
How do I know if a tankless water heater is right for my home?
It depends on your hot water demand and setup. Homes that run multiple fixtures at once typically need a properly sized gas tankless system. If it’s matched correctly, you’ll get consistent hot water without running out.
What size tankless water heater do I need?
Tankless systems are sized based on flow rate (GPM) and heating capacity (BTU). The right size depends on how many fixtures you use at the same time. Undersized systems are the most common cause of temperature drops.
Are tankless water heaters better than traditional tank systems?
They provide on-demand hot water and take up less space, but they need to be sized and installed correctly. For some homes, a traditional tank system may still be the better fit depending on demand and setup.
How long do tankless water heaters last?
With proper maintenance, tankless systems can last 15–20 years or more. Regular flushing helps prevent buildup and keeps performance consistent.
Do tankless water heaters require maintenance?
Yes. Tankless systems should be flushed regularly to remove scale buildup. Skipping maintenance can lead to reduced efficiency and performance issues over time.
Why does my tankless water heater fluctuate or lose hot water?
This is usually a sizing or setup issue. If the system can’t handle demand or wasn’t configured properly, you’ll notice temperature changes when multiple fixtures are used.
Can I replace my tank water heater with a tankless system?
Yes, but it often requires updates to gas lines, venting, or electrical components. The installation needs to be evaluated to make sure the system will perform properly.
What brands of tankless water heaters do you work with?
We work with most major brands, including Rinnai, Navien, Rheem, Noritz, and A. O. Smith, and can recommend the right option based on your home and usage.
Do you service all of Northern Virginia?
Yes. We provide tankless water heater installation, repair, and maintenance across Northern Virginia, including Fairfax County, Prince William County, Loudoun County, and surrounding areas. If you’re unsure about your specific location, just reach out and we can confirm service availability quickly.
MORE PLUMBING SERVICES
COMPLIMENTARY PLUMBING EVALUATION
Worried about problems in your plumbing? Our plumbing evaluation is completely free. We’ll inspect every part of your home’s plumbing to ensure it’s working at its best, and to spot issues that could cause a leak or other problems.
PROFESSIONAL PLUMBING REPAIRS
Dealing with leaks, clogs, or other issues? HVAC & Plumbing Unlimited offers expert plumbing repairs, from fixing dripping faucets and leaky pipes to resolving clogs and malfunctioning toilets.
AFFORDABLE WELLS FARGO FINANCING
Money should never get in the way of your family’s safety and comfort. We’ve arranged special payment options through Wells Fargo Financing that let you start enjoying your new system or repairs right away and pay for it over several months.
TOILETS, FAUCETS & FIXTURES
Replacing toilets, faucets, and other plumbing fixtures is a great way to update the look and convenience of your home. We can recommend products that will provide both beauty and problem-free reliability for years to come.