Tankless water heater installation in Philadelphia, PA

Why a tank-to-tankless conversion is not a like-for-like swap

A tank water heater and a tankless unit ask different things of the house around them, and that difference is where a rushed installation goes wrong.

The gas line usually needs to grow. A standard 40 or 50-gallon tank heater runs on a modest BTU input and a relatively small gas line. A whole-house tankless unit fires at a much higher BTU rate to heat water instantly instead of storing it, and that often means the existing gas line has to be upsized, sometimes back to the meter, to deliver enough volume. We calculate the actual BTU demand and check the existing line before we commit to a unit.

The venting is a different system entirely. Older tank heaters typically vent through a Type B metal flue into a shared chimney. Many tankless units, especially high-efficiency condensing models, vent through PVC or CPVC pipe routed directly outside, which means the old chimney flue often gets capped rather than reused. Row homes with interior chimneys shared between a water heater and a furnace need this looked at carefully, since removing the water heater’s draft can affect how the rest of the flue performs.

Permits and inspection are not optional, even on a replacement. The City of Philadelphia requires a plumbing permit for water heater installations, tankless conversions included, and the work gets inspected. Per the City of Philadelphia Department of Licenses and Inspections, plumbing work of this kind requires a licensed tradesperson and a permit application before the work begins. Skipping that step is how homeowners end up with an installation that fails inspection later, usually at resale.

This is why a tankless quote should never come from a phone call alone. The gas line, the venting path, and sometimes the electrical panel all need to be looked at in person before a real number and a real unit recommendation are possible.

What our tankless installation covers

We evaluate the whole system, not just the unit going on the wall. The work involved in a typical tankless installation:

Sizing for actual household demand

Tankless units are rated by gallons per minute at a given temperature rise, not by tank capacity, and undersizing is the most common mistake in a rushed installation. We size based on how many fixtures could realistically run hot water at once in your home, not a generic household average.

Gas supply evaluation and upsizing

If the existing gas line and meter cannot support the BTU input of a whole-house tankless unit, we calculate the required pipe size and handle the upsizing as part of the installation, coordinating with PGW where the service line itself needs attention.

Venting design and installation

We determine whether the unit requires PVC, CPVC, or stainless steel venting, route it to a code-compliant termination point, and cap or repurpose the old flue correctly so it does not become a hazard for any other appliance still using it.

Electric tankless installation

For homes on electric service, or for point-of-use units in a kitchen or bathroom addition, we confirm the electrical panel has the capacity for the unit’s amperage draw and coordinate with an electrician when a panel upgrade is needed.

Tank-to-tankless conversion

This is the most common call we get: removing an aging tank unit and converting the same location to tankless. We handle the disconnection, disposal of the old tank, and the full install of the new system in one visit where the gas and venting allow it.

New construction and addition installations

For additions, finished basements, or accessory dwelling units where there was no water heater before, we plan the gas, water, and venting runs from scratch and size the unit for the added fixture load.

Permit and inspection

We file the L&I plumbing permit, schedule the required inspection, and make sure the finished installation is documented and code-compliant, not just functional.

Pricing and financing

We do not publish a flat tankless installation price, because a straightforward same-location conversion and a job that requires gas line upsizing, new venting, and an electrical upgrade are not comparable jobs. We inspect the existing gas line, venting path, and electrical service on-site and give you a firm number before any work starts.

Why tankless costs more upfront. A tankless unit and its installation typically cost more than a like-for-like tank replacement, mainly because of the gas, venting, and sometimes electrical work involved, not just the unit itself.

Efficiency payoff over time. Per the U.S. Department of Energy, demand water heaters can be 24 to 34 percent more energy efficient than conventional storage tank water heaters for households using 41 gallons or less of hot water a day, and 8 to 14 percent more efficient for higher-use households. Tankless units also typically last longer than tank units, which changes the lifetime cost comparison even where the upfront number is higher.

Financing. For tankless installations and conversions, we offer instant approval financing through GoodLeap.

What to expect when we install

1. An in-person evaluation before any quote. We look at the existing gas line size and meter capacity, the current venting path, the electrical panel if relevant, and the household’s actual hot water usage. A tankless quote given without seeing the house is a guess, and we do not give those.
2. A unit recommendation sized to the house. Based on that evaluation, we recommend a specific unit type and capacity, gas or electric, whole-house or point-of-use, and explain why it fits your situation.
3. Permit filed before work begins. We submit the L&I plumbing permit application so the installation is on record and scheduled for inspection.
4. Installation day. We disconnect and remove the old unit if one exists, run and connect any new gas piping, install the venting to code, mount and connect the new tankless unit, and test the system under load before we consider the job finished.
5. Inspection and walkthrough. Once the required L&I inspection is complete, we walk you through how to maintain the unit, including the descaling interval that matters most in Philadelphia’s water conditions, and leave you with the documentation for the installation.

What our clients say about our tankless installations

★★★★★ 863 reviews

Credentials that matter for tankless installation in Philadelphia

A tankless installation touches gas piping, venting, and sometimes electrical work, three systems where a mistake creates a real safety risk. The Philadelphia Department of Licenses and Inspections requires a licensed tradesperson and a permit for this work, and we file and pass that inspection on every install. We have been operating under these standards since 1990.

• Licensed Master Plumber for the plumbing work we do
• BBB accredited
• Insured for the work we do, liability and workers’ compensation on file with L&I
• Family-owned and operated in the Philadelphia area since 1990