Tankless Water Heaters

Tankless Water Heater Replacement on Long Island

On-demand hot water, wall-mounted, never runs out. Our tankless water heater replacement service on Long Island covers Navien and Rinnai installs, tank-to-tankless conversions, and the annual descale work that keeps these units alive in LI hard water.

Call Now (631) 898-5780

★★★★★

Tankless retrofits and direct swaps, both done right.

Navien & Rinnai Gas Line + Venting Upgrades 15-Year Heat Exchanger Coverage LI Hard-Water Flushes

Why Tankless

Why Long Island Homeowners Switch to a Tankless Water Heater

Tankless is not magic and it is not the right answer for every home. When it fits, here is what changes.

▸Endless hot water. Within the unit's flow rate, you cannot run out. Soaker tubs, back-to-back showers, dishwasher and laundry running simultaneously — no problem.
▸Wall-mounted, suitcase-sized. Frees up floor space in a tight basement or utility closet.
▸Longer lifespan. 15 to 20 years versus 10 to 12 for a tank. Heat exchanger warranties up to 15 years on the major brands.
▸Higher efficiency. No standby losses heating water you are not using. Energy bills drop, especially during summer.
▸Rebate eligible. High-efficiency gas tankless can qualify for National Grid rebates.

Tankless water heater replacement on Long Island by Domino Home Services

NAVIEN & RINNAI

More About Our Long Island Tankless Service

What Tankless Water Heater Replacement Looks Like on Long Island

Tankless water heater replacement is one of the most common upgrade calls we get on Long Island. Most jobs start with a homeowner who has lived through one too many "I ran out of hot water" mornings, or who wants to reclaim the floor space a 5-foot tank is occupying. We install Navien and Rinnai tankless units, handle gas line and venting upgrades when they are needed, and register the manufacturer warranty in your name on install day.

Long Island water is hard enough that tankless units need an annual descale flush to keep the heat exchanger clean and the warranty valid. We do those flushes as a service call or coach you through the DIY version. The maintenance routine is important to be honest about: tankless is a great fit for the right home, but it does ask more from the homeowner than a standard tank.

Is It Right for You?

Who Tankless Water Heater Replacement Works For

The biggest factor is hot water demand. The second is how long you plan to stay in the house.

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Big or Growing Families

4+ people, heavy simultaneous use, kids who shower for 25 minutes. Tankless is built for this.

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Long-Term Homeowners

Planning to stay 10+ years? The longer lifespan and lower bills give the install premium time to pay back.

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Space-Tight Basements

If a 5-foot-tall tank is in the way of finishing your basement, a wall-mounted tankless solves that.

When tankless is NOT the right call: tight budget, you're only staying 3 to 5 more years, your gas line is 1/2 inch and running a new line would be expensive, or you can't easily vent to the outside. In those cases, a high-quality tank is the smarter spend. We will say so.

Brands We Install

Tankless Water Heater Brands We Install

Both brands are excellent. We pick between them on a per-job basis based on flow rate needs, install location, and budget.

NAVIEN

Navien NPE Series

Excellent build quality, condensing efficiency, strong cold-weather performance for LI winters, and a 15-year heat exchanger warranty. Our most common pick for whole-house jobs in 4+ bath homes.

▸Up to 11 GPM flow rate (NPE-A2 series)
▸15 yr heat exchanger / 5 yr parts
▸WiFi monitoring built in

RINNAI

Rinnai Sensei Series

Veteran tankless brand, exceptional reliability, easy serviceability, and parts availability we can get same day. Slightly smaller footprint than Navien on comparable models.

▸Up to 11 GPM flow rate (RX series)
▸15 yr heat exchanger / 5 yr parts / 1 yr labor
▸Excellent customer support network

The Conversion Reality

What a Tank-to-Tankless Water Heater Conversion Involves

Honest version: tankless retrofits are more involved than tank swaps. Most of the time, here is what they require.

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Larger Gas Line

Tankless burners need more gas flow. We frequently upsize from a 1/2 inch line to 3/4 inch back to the meter.

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New Venting

Tankless cannot vent into a standard chimney. We run stainless or PVC vent through the wall, sized to the unit.

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Condensate Drain

Condensing tankless units produce condensate that needs a drain line. We plumb to a nearby drain or run a condensate pump.

The Long Island maintenance reality: tankless units are sensitive to hard water. The water on LI is hard enough that scale will build up inside the heat exchanger over time. The fix is simple: an annual descale flush. We do them as service calls or coach you through DIY. Skipping the flush is the #1 reason LI tankless units fail early and the #1 way to void the manufacturer warranty.