Tankless Water Heater Replacement in Portsmouth, NH
From aging Rinnai and Takagi units to tank-to-tankless swaps, we handle tankless water heater replacement in Portsmouth, NH with clean installs and upfront pricing.
- Prompt Tankless Replacement
- Transparent Pricing
- Top Brands Available
- Code Compliant
Stop Waiting on Lukewarm Showers. Upgrade Your Tankless in Portsmouth, NH.
Contact us today for a free estimate and see the benefits of on-demand hot water.
Your Go-To for Tankless Water Heater Replacement in Portsmouth, NH
FVR Plumbing handles every part of a tankless swap, including removing the old unit, upgrading the gas line if needed, installing new concentric or PVC venting and adding service valves for annual flushing. You get a clean, code-compliant install and a walkthrough of how to keep the heat exchanger healthy.
Our expertise includes:
- Gas line sizing and upsizing for 199,000 BTU tankless units
- Scale prevention with isolation valves and inline filtration options
- Careful sizing and installation of new tankless units.

Additional Plumbing Replacement Services in Portsmouth, NH
When repairs are no longer enough, our replacement services in Portsmouth, NH deliver durable upgrades that restore full performance.

Customers
Why Choose FVR Plumbing for Tankless Water Heater Replacement in Portsmouth, NH?
Testing well water around Portsmouth is the right first step before choosing a neutralizer or filter. Hard water is tough on tankless heat exchangers, and many early failures trace back to scale and skipped flushing. We size, install and set up each replacement so it holds up to your local water supply.
- Right-Sized Units, We calculate gallons per minute and temperature rise for your fixtures instead of guessing from square footage.
- Scale Protection, Every install includes isolation valves so the heat exchanger can be descaled without cutting into the pipes.
- Energy Savings, Tankless water heaters only heat water when you need it, which can noticeably reduce energy use compared to traditional tank models, a big plus for New Hampshire utility bills.
Citywide Coverage
We replace tankless water heaters in every neighborhood of Portsmouth, from newer builds with garage-mounted units to older homes converting from a tank. Our trucks carry venting kits and gas fittings for both interior and exterior installs.
Experienced Team
Each technician at FVR Plumbing is a specialist in tankless technology, so your replacement is done accurately and efficiently. We focus on details like proper gas line sizing, venting and electrical connections for top performance and safety.
Safety-First Approach
Safety and code compliance come first in every tankless water heater replacement we perform. Our installations follow all New Hampshire and local Portsmouth plumbing and gas codes, so your system runs safely and efficiently.
Trusted Certified Portsmouth Plumbing Services Professionals
At FVR Plumbing, we take pride in providing certified plumbing services throughout Portsmouth, NH. Backed by leading industry credentials, our experienced plumbers combine technical skill with genuine customer care. Whether it is repair, installation, or maintenance, we follow strict safety and quality standards to deliver long-lasting results you can trust.
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PHCC Plumbing Contractor Recognition
Better Business Bureau (BBB) Accreditation
Angi Certified Pro
ISO 9001 Quality Management CertificationTrusted Tankless Water Heater Replacement Services in Portsmouth, NH
Recirculation Tankless Upgrades in Portsmouth, NH
If you are tired of running the tap while you wait for hot water, a tankless with a built-in recirculation pump can bring heat to the fixture in seconds. Navien A series and Rinnai units with internal pumps can use a dedicated return line or a crossover valve under the farthest sink. We program schedules so the pump runs only during your morning and evening peaks. That keeps gas use in check while saving thousands of gallons of wasted water a year. This upgrade is popular in long single-story ranch homes.

Condensing Tankless Replacement in Portsmouth
Condensing tankless units like the Navien NPE series or Rinnai Sensei reach efficiencies above 90 percent by recovering heat from exhaust gases. They vent through inexpensive PVC and produce acidic condensate that must be neutralized and drained properly. We install a neutralizer cartridge and route the condensate line to an approved drain. Humid summers bring sweating on cold water lines and damp basements that can hide slow leaks. Condensing units still save gas because they work year-round on showers, laundry and dishes. We explain the cost difference so you can decide if the efficiency gain is worth the price.
Exterior Mount Tankless Units in Portsmouth, NH
Many homes have tankless heaters mounted on an exterior wall with no venting at all, since the unit exhausts directly outside. These units face sun, rain and temperature swings, which can wear out plastic covers and wiring over time. Frozen pipes are a regular winter risk in New Hampshire, especially during long stretches of subzero nights and strong wind. When we replace them, we check the pipe cover, freeze protection settings and the electrical connection. We can add a protective pipe cover kit to shield the water and gas lines. Exterior models are often the simplest swap when the gas line is already sized correctly.
Tankless vs. Tank Water Heater Conversion in Portsmouth, NH
Thinking about converting from a traditional tank water heater to a tankless system in your Portsmouth, NH home? This is a common and beneficial upgrade, but it requires specialized expertise. We handle the entire conversion, which can involve rerouting gas lines, upgrading electrical service, modifying water lines and installing new venting. Our team ensures a smooth transition, so you can enjoy the long-term benefits of a modern, efficient tankless system.
Like-for-Like Tankless Swaps in Portsmouth
When your existing tankless has a cracked heat exchanger or a failed control board that is not worth repairing, a direct replacement is often the quickest fix. We match the new unit to your current gas line, venting type and mounting location whenever possible. Many Rinnai and Navien models share similar footprints, which keeps wall patching to a minimum. We also replace the old service valves if they are corroded or seized. Most like-for-like swaps are done in four to six hours.
Electric Tankless Water Heater Replacement in Portsmouth, NH
For properties without natural gas access or those looking for an all-electric solution, electric tankless water heaters are a viable choice. FVR Plumbing offers electric tankless water heater replacement services in Portsmouth, NH. This often involves careful assessment of your home's electrical panel capacity, as these units require substantial amperage. We make sure your new electric tankless unit is installed safely and correctly, providing on-demand hot water without the need for gas lines.
Tankless vs. Tank Water Heater Replacement Cost in Portsmouth, NH
When considering tankless water heater replacement in Portsmouth, NH, it is natural to compare costs. While the upfront installation of a tankless unit can be higher than a traditional tank, the long-term energy savings and longer lifespan often make it the more cost-effective choice. We provide clear, upfront pricing for both options. That helps you make an informed decision based on your budget and hot water needs, with no surprises.

Gas Tankless Water Heater Replacement in Portsmouth
Many homes in Portsmouth rely on natural gas for water heating, and gas tankless units are a very efficient option. Our gas tankless water heater replacement service includes careful inspection of your existing gas lines, proper sizing of new gas lines if needed, and secure venting to the outdoors. We put a priority on safety. All gas connections and combustion air requirements meet New Hampshire and local codes, heading off potential hazards and maximizing efficiency.
Tankless Water Heater Replacement Near Me in Portsmouth, NH
If you are searching for tankless water heater replacement near me, you want a local plumber who understands New Hampshire water and gas codes. FVR Plumbing serves Portsmouth with trucks stocked for tankless installs. We can usually give you a firm quote after a short phone call and a few photos.
Local service matters because tankless problems often show up during the busiest part of your day. Our techs are close by and can figure out whether a repair or replacement makes more sense. We back every replacement with clear labor coverage and register your manufacturer warranty for you.
FVR Plumbing at a Glance
- Fully licensed plumbing team covering Portsmouth, NH
- 24/7 emergency service with same-day scheduling
- Clear written estimates, no hidden fees
- 4.9-star rated by 840+ New Hampshire customers
Portsmouth Map
Portsmouth Information
- Population
- 22,733
- Area codes
- 603/857/978
- Service area
- Portsmouth and communities within 40 miles
- Nearby
- Durham, Dover, Exeter, Somersworth
Replacing your tankless water heater in Portsmouth, NH is a sound investment, especially with seasonal temperature swings and the need for efficient hot water in modern homes.
Expert Services
Trust our professionals for reliable FVR Plumbing solutions in Portsmouth, NH.
Our Specialized Plumbing Services in Portsmouth, NH
At FVR Plumbing, we provide a complete range of plumbing services across Portsmouth, NH. From leak detection to full system installations, our team ensures fast, precise, and affordable service for both residential and commercial properties. Explore our core services below:
How Our Tankless Water Heater Replacement Process Works in Portsmouth, NH
Replacing a tankless heater takes planning around gas, venting and water. Here is how we keep it simple.
Request a Quote
Call us at (844) 442-1569 or fill out our online form to schedule an first consultation. We will discuss your hot water needs and current system issues, and provide a detailed, upfront estimate.
On-Site Assessment
Our licensed plumber will visit your Portsmouth home to look over your existing water heating system, plumbing, gas or electrical connections and venting. This helps us recommend the right tankless model and make sure it is properly sized for your household.
Expert Installation
Once you approve the quote, our team will proceed with the professional installation of your new tankless water heater. We carefully remove the old unit, make any needed plumbing or gas line changes, and make sure the new system is correctly vented and fully operational.
Frequently Asked Questions About Tankless Water Heater Replacement in Portsmouth
The cost for tankless water heater replacement in Portsmouth, NH typically ranges from $3,000 to $6,000, depending on the unit's brand, capacity, fuel type (gas or electric) and any needed changes to gas lines, electrical or venting. This estimate includes both the new unit and professional installation. We will provide a detailed quote upfront after assessing your needs.
Well-maintained tankless units can last 15 to 20 years. In hard water areas without regular descaling, heat exchangers can fail much sooner. Annual flushing makes the biggest difference.
Tankless water heater replacement is a complex job that involves gas lines, electrical wiring, water connections and venting. It is strongly recommended to hire a licensed professional like FVR Plumbing due to the safety risks and potential for improper installation, which can lead to leaks, gas hazards or inefficient operation. Professionals also protect code compliance and warranty validity.
To extend the life and efficiency of your new tankless water heater, regular maintenance is crucial, especially in areas with hard water. This usually involves annual flushing to remove mineral buildup, checking the air filter, and inspecting gas and water connections. FVR Plumbing offers maintenance plans to help keep your unit in top condition.
Yes, you can certainly replace a traditional tank water heater with a tankless unit. This is a common upgrade for homeowners seeking better energy efficiency and endless hot water. However, it often requires changes to gas lines, venting and possibly electrical wiring, making professional installation essential for safety and performance.
We install Navien, Rinnai, Noritz, Takagi and Rheem tankless heaters. Each has its own strengths, and we recommend based on your flow needs, venting options and budget.
We do not recommend it. Gas line sizing, venting clearances and combustion testing call for training, and improper installs can void the warranty or create carbon monoxide hazards.
A standard tankless water heater replacement usually takes between 4 and 8 hours. This timeframe can vary based on whether we are replacing an existing tankless unit with a similar model or upgrading from a traditional tank water heater. A tank conversion may require more extensive changes to gas lines, electrical or venting.
What People Are Saying About Our Plumbing Experts?

Daniel K.
A pipe burst at 11 pm and they actually answered. The plumber showed up within the hour, shut everything down, and had us back to normal the next morning. Could not ask for more.
Emergency Plumbing · Rochester, NH
Mark T.
When our office needed drain cleaning, FVR Plumbing provided quick, reliable service. The plumber arrived on time and made sure every drain flowed perfectly before leaving. Very satisfied.
Drain Cleaning · Derry, NH
Sofia M.
Two new toilets installed in one visit, no mess left behind, and the tech even adjusted a faucet he noticed was dripping. Fair pricing and really friendly.
Toilet Installation · Rochester, NH
Emily R.
I called FVR Plumbing for plumbing repair, and the technician was fast, polite, and thorough. They explained the problem clearly and fixed it the same day. I will definitely hire them again. Highly recommended!
Plumbing Repair · Portsmouth, NH
Patricia H.
We had a slab leak that two other companies could not find. FVR Plumbing located it in under an hour, explained our options, and the price matched the quote to the dollar.
Slab Leak Repair · Dover, NH
Laura S.
I scheduled a water heater replacement, and the team made the process smooth and affordable. The new unit works perfectly, and they cleaned up after completing the job.
Water Heater Replacement · Portsmouth, NH













