Who Installs a Tankless Water Heater: Plumber or Electrician? Here’s How to Decide

Homeowners in Modesto ask us a version of this question every week: do I call a plumber or an electrician for a tankless water heater? The short answer is that you need both skill sets. The long answer matters more, because the right installer affects performance, safety, and the lifespan of your system.

At Knights Plumbing and Drain, we handle tankless installations end to end across Modesto, Riverbank, Salida, Turlock, and nearby neighborhoods. We coordinate gas, water, venting, and electrical so you are not stuck piecing together two contractors. If you are searching for tankless water heater installers near me and want a single accountable team, this guide will help you decide what you actually need and why it pays to get it right the first time.

Plumber or electrician: who does what, exactly

A licensed plumber leads the project for both gas and electric tankless units. The plumber sizes the unit based on your hot water demand, upgrades gas lines, sets pipe layout, handles venting for gas models, and mounts the unit. The electrician’s role depends on the model. Gas units need a powered ignition and often a dedicated 120V circuit. Electric units need heavy-gauge wiring and multiple high-amperage breakers. In real homes, there are surprises behind walls, so the installer’s field judgment matters as much as credentials.

Here is the practical split we see on Modesto projects: the plumber is the primary installer and code signer for the water, gas, and venting. The electrician supports by adding or upgrading circuits. On some jobs, a single company like ours handles both scopes under one permit set. That avoids scheduling gaps and finger pointing if something needs adjustment.

Gas vs. electric tankless: what your home demands behind the scenes

If you are early in the decision, start by checking what your home can support.

Gas tankless units thrive in homes with natural gas service and space for safe venting. They deliver high flow rates even in winter when groundwater runs cold. In Modesto, winter incoming water can drop into the low 50s°F. If you want to run two showers and a dishwasher at once, gas often makes sense. Expect gas line upsizing to 3/4 inch or more, especially if your current tank used 1/2 inch. Venting usually uses category III or IV stainless steel or PVC for condensing models. Clearance rules near windows, eaves, and property lines are strict, and inspectors here watch terminations closely due to our valley winds.

Electric tankless units avoid venting and gas, which sounds simple, but they draw serious amperage. A whole-home electric tankless can need 120 to 160 amps across three or four double-pole breakers. Many Modesto homes have 100 to 150 amp main service. If your panel is already loaded with HVAC, range, and dryer, you may need a service upgrade to 200 amps. That turns a quick install into a utility-coordinated project. Electric point-of-use units at a single sink or an accessory dwelling can be practical without a full panel upgrade, but whole-home electric often demands planning.

How we size your tankless the right way

Sizing is where installs succeed or fail. We calculate your peak gallons per minute and the temperature rise needed from your winter groundwater baseline. In Modesto, we use 50 to 55°F as the starting point. If you want 120°F at fixtures, a 65 to 70°F rise is realistic. A standard shower uses around 2 gallons per minute. Two showers and a washing machine can push 5 to 6 gallons per minute. A 199,000 BTU gas unit can deliver roughly 5 to 7 gallons per minute at that rise. An undersized unit will throttle flow or plunge to lukewarm during back-to-back showers. An oversized unit can short cycle if your usage is light, which accelerates wear.

We also look at your water quality. Parts of Stanislaus County have hard water in the 15 to 20 grains per gallon range. Scale forms quickly on heat exchangers. If we see heavy scale at fixtures, we recommend a prefilter and a scale-reduction system. It is a modest added cost that protects your investment and keeps your energy use in check.

Permit, code, and inspection in Modesto

Tankless installs here require permits for mechanical (venting), plumbing, and sometimes electrical. Gas work must follow California Mechanical Code, California Plumbing Code, and the appliance manufacturer’s instructions, which the inspector will treat as code. We submit load calculations if we upgrade a gas line or electrical panel. In the City of Modesto, inspectors are precise about combustion air, vent clearances, and seismic strapping on any related equipment. If you live in Salida, Riverbank, Ceres, or Turlock, we handle the jurisdiction differences for you. Most inspections complete within two visits: rough and final. A clean inspection record helps your resale value and protects your warranty.

What can go wrong if the wrong trade leads

We get calls to fix installs done piecemeal. The recurring issues are predictable. A gas unit vented with the wrong material corrodes in months, then fails an inspection or triggers an error code. A unit hung in a garage without proper clearances gets dinged, or worse, overheats. An electric model fed by an undersized breaker trips during showers. We have also seen gas lines starved by under-sized branches when the furnace, range, and tankless all fire during a cold snap. The homeowner experiences fluctuating water temps and blames the unit, when the real issue is gas supply. These are avoidable with the right eyes on the plan.

How to decide who to hire

If you choose a gas tankless, hire a licensed plumbing contractor with proven tankless experience who can manage venting and gas sizing and bring in an electrician as needed. If you choose an electric whole-home tankless, hire an installer who can perform a full electrical load calculation, coordinate panel upgrades, and handle permits. The common thread is coordination. A single company that does both scopes is simpler and faster. If you insist on separate trades, make one the quarterback. Share the spec sheet, gas load data, and panel schedule with both.

If you are searching for tankless water heater installers near me in Modesto, prioritize installers who can show local references, pull permits in your city, and explain their sizing math. A clear plan up front beats guesswork on install day.

What the install day actually looks like

Most replacements take one day for straightforward gas swaps and one to two days if we upsize gas, extend venting, or move the location. Electric whole-home installs often stretch to two days, and longer if a panel upgrade is required. We shut off water and gas for parts of the day, but we aim to keep downtime to a few hours. We purge air from lines and walk you through the controller. Expect a brief learning curve on flow behavior; tankless units love steady demand and can “hunt” if a faucet trickles. We show you the minimum flow behavior so you avoid nuisance fluctuations.

We mount a service valve kit on every install. That lets you flush the heat exchanger with vinegar or descaler yearly, which matters in our hard water. We label gas and electrical shutoffs and leave you with the model’s maintenance schedule.

Costs you can plan for in the Modesto area

Budget is a real factor. A quality condensing gas tankless unit with install commonly lands between $3,500 and $5,500 in our region, including venting and a reasonable gas line run. If we need to upsize a long gas line or core-drill through masonry, costs can climb. Electric whole-home installs may look cheaper on the unit price, but panel work can swing the total. If your service needs an upgrade to 200 amps, plan on an added $2,000 to $4,000 depending on utility coordination, trenching, and meter location.

Maintenance costs are modest. A yearly flush usually runs $150 to $250. Skipping maintenance shortens the life of the heat exchanger, especially with hard water. Warranties vary by brand; many offer 10 to 12 years on heat exchangers when installed by a licensed pro and registered on time.

Energy use and monthly bills

Gas tankless units avoid standby losses from keeping 40 to 50 gallons hot all day. Real savings vary with usage patterns. Homes with steady daily hot water use see the best efficiency. Electric tankless can cost more to run per BTU in our area unless you have low electric rates or solar. If you run a heat pump water heater comparison, that is a different conversation, but for pure on-demand flow at high GPM, gas remains common in Modesto because of winter inlet temps and existing gas infrastructure.

If you want the lowest monthly cost and already have gas, a condensing gas tankless with a softening or scale system is a solid choice. If you lack gas and cannot vent readily, an electric point-of-use tankless near a bathroom or studio can be a smart, targeted solution without reworking the whole home.

The tankless myths we correct most often

We hear that tankless means instant hot water at every tap. It means endless hot water once it reaches tankless water heater services near me you, but you still wait for hot water to travel through your pipes. If you want near-instant delivery at a far bathroom, we add a recirculation loop or pair the tankless with a demand pump. Another myth is that tankless always saves money on every bill. It can, but only if sized and set up correctly, and only relative to your use. A third myth is that you can swap a tank for a tankless without changing venting or gas size. That shortcut leads to callbacks and unhappy mornings.

How we set you up for long-term reliability

We install a scale filter when hardness is high. We set outlet temperature at 120°F for safety and stability. We program recirculation schedules if your unit supports it, often aligning with morning and evening routines. We show you the flush ports and recommend a yearly reminder. We keep parts on the truck that actually fail: igniters, flame rods, flow sensors, condensate neutralizers. A fast swap beats a cold shower. We save your install photos and line sizes in our system so any future tech can help you quickly.

Real scenarios from around Modesto

North Modesto, Vintage Faire area: a two-bath home with a 40-gallon tank struggled with teenage shower overlap. We installed a 199k BTU condensing tankless on the exterior wall with a short vent and upsized the gas line 25 feet. Added a small recirculation pump tied to a motion sensor in the main bath. The family reports stable temps and shorter wait times at peak hours.

Riverbank bungalow: no gas service, 100 amp panel, one bath. The owners wanted a space-saving option. We installed an electric point-of-use tankless under the bathroom sink and kept a small traditional electric tank for the rest of the home. No panel upgrade needed, and it solved the morning routine without a big electrical project.

Salida new addition: the main house had gas, but the new in-law suite sat far from the mechanical room. Instead of extending hot water lines across the attic, we mounted a small gas tankless on the suite’s exterior wall with dedicated venting. Short runs mean faster hot water and lower heat loss.

These choices came from the same process: measure, verify utilities, weigh trade-offs, and install to code.

Choosing the right brand and features

We service and install major brands that stock parts locally. In Modesto, that parts availability matters more than brand folklore. Features to consider include built-in recirculation, freeze protection if mounted outdoors, scale detection alerts, and wi-fi diagnostics if you like remote monitoring. Outdoor installs free up indoor space and simplify venting, but they need freeze protection and clearances. Indoor installs avoid weather but add venting constraints. We walk through the pros and cons for your floor plan and lot.

Safety you should never compromise

Carbon monoxide is silent and unforgiving. Proper vent materials, pitch, termination, and combustion air keep your home safe. We test for gas leaks with a manometer and soap test, and we clock the meter to confirm total load. For electric units, we pull permits, use the correct wire gauge, torque lugs to spec, and label breakers. We bond the gas line and verify grounding. These steps do not show on a glossy brochure, but they are why your system runs safely for years.

How to get a dependable quote that sticks

Invite us for a site check. We measure pipe sizes, check your panel, run a gas load, and test water hardness. We ask about your morning routine and how many fixtures run at once. You get a clear scope that includes venting, gas or electrical upgrades, recirculation options, and maintenance. That is how we avoid change orders. If you are comparing quotes from other tankless water heater installers near me, look for the same level of detail. A low number that omits venting or gas upsizing often grows later.

Simple checklist before you book

• Confirm gas availability or panel capacity for your preferred fuel.
• Count your simultaneous fixtures at peak times.
• Note your longest pipe run to the farthest fixture.
• Ask if venting or recirculation is part of the plan.
• Verify permits and inspections are included.

Why Modesto homeowners trust a plumber-led install

This question loops back to where we started. A plumber-led install works because the system’s core is water, gas, and venting. The electrician’s work is critical on electric models and supporting gas models, and we value that partnership. But the day-to-day performance issues you feel in the shower trace back to sizing, piping, vent path, and gas supply. That is our wheelhouse. A single accountable team removes friction and speeds up service if you need help later.

If you are ready to replace a tank or planning a remodel in Modesto, Riverbank, Salida, Ceres, Turlock, or Ripon, schedule a visit. Knights Plumbing and Drain will evaluate your home, explain your options in plain terms, and deliver a neat, code-ready install that works the way you expect. Search tankless water heater installers near me and you will find plenty of names. Choose the one that shows their math, stands behind the work, and answers your questions without jargon.

Ready to talk options for your home

Call or book online to set a no-pressure assessment. We will check your gas line or panel, measure your flow needs, and give you a firm price with permits included. If the best choice is gas, we will size the vent and line correctly. If electric fits, we will confirm the panel and coordinate any upgrade with your utility. If a point-of-use unit solves a single-bath problem, we will say so. Clear advice beats guesswork, and a proper install beats a second visit.

Hot water should be simple. We make it that way for Modesto homeowners, one solid install at a time.