Published guides price a whole-house tankless unit, mounted and running, anywhere from $1,400 up to $5,600, and fuel type splits that spread in two: electric models start low and top out near $3,000, while gas models begin around $2,100. Treat those as orientation. The real figure comes on paper after a plumber has looked at your house. If a heater has just failed, begin at our water heater repair hub.
What does a tankless install cost, line by line?
Picture the bill as a ladder. The unit comes first, labor second, then whatever your house demands on top: gas pipe, a new vent, electrical capacity, a permit. Labor by itself is quoted at about $600 to $2,500 across three to ten hours of work, and the unit itself often makes up over half the total.
| Rung on the ladder | Guide range |
|---|---|
| Electric tankless, complete | $1,400 through $3,000 |
| Gas tankless, complete | $2,100 through $5,600 |
| Labor only | $600 through $2,500 |
| Gas pipe upsizing | roughly $300 up to $1,000 |
| New venting | roughly $300 to $600 |
| Electrical panel or circuit work (electric units) | often $500 to $2,000 |
| Permit and inspection | commonly $50 to $500 |
Converting away from a tank costs extra compared with a like-for-like exchange, since walls, pipe and vents all change. If you have not chosen a type yet, the tank versus tankless comparison comes first.
Why is a gas tankless job pricier in an older Long Beach house?
A tankless burner draws many times the fuel a tank does, and the half-inch gas pipe that fed a stove and a small tank in a 1930s or 1940s house is often too narrow. Add a vent route through a wall or roof and the extra hours show up. Hence the high end of the range belongs to gas.
What the plumber measures before quoting:
- Gas pipe size and run length, from the meter to the heater location.
- The total load of furnace, range, dryer and the new unit, since the meter must carry everything at once.
- Vent path. Stucco, tile roofs and tight lot lines near the harbor change the route.
- Water line size. Most units want three-quarter-inch connections.
- Location. A garage needs the ignition source raised above the floor under Long Beach code, and fuel-burning heaters cannot sit in bedrooms or bathrooms.
Houses in Belmont Shore and Bixby Knolls, with their 1920s to 1950s bones, frequently need more of this than a Lakewood tract home. Our tankless installation walkthrough shows what happens on the day.
What do tank-style water heater replacements cost?
A conventional 40 or 50 gallon tank is listed at roughly $800 up to $2,500 fully installed, with electric versions near $700 to $2,350 and gas versions near $900 to $3,200. Labor alone runs about $200 to $600 for electric and $400 to $1,000 for gas, since gas adds connections, venting and code work.
Smaller differences:
- 40 versus 50 gallons. The labor is identical. The unit costs a little more, about $40 to $100 for electric and $80 or more for gas.
- Hot water heater replacement labor. Planning around $75 to $150 an hour is common, and a permit sits on top.
- Extras. A panel upgrade, a new expansion tank or a new earthquake strap kit add to the ticket.
California's rules apply to every swap. In Long Beach a residential water heater swap calls for a plumbing permit, a cold water shutoff at the unit, earthquake straps on every heater, electric ones included, and an inspection. Tank jobs get a deeper treatment on the replacement pricing page.
How much do the small parts and valves cost?
Small repairs cost a fraction of replacing the whole heater. Published figures: an anode rod replacement runs about $150 to $350 with a plumber, a gas control valve about $300 to $500, and a relief valve for temperature and pressure about $150 to $300. An expansion tank adds roughly $200 to $400.
A few notes on each:
- Anode rod. The sacrificial rod protects a steel tank from corroding. Replacing it can extend the life of an older tank, but a seized rod or a low ceiling can push the bill toward $400 or more. See the anode rod page.
- Gas valve. The control valve is a safety part, so a plumber handles it. The gas water heater cost guide covers the whole-unit alternative.
- Relief valve. A dripping T&P valve is often caused by high house pressure or thermal expansion, not a bad valve. Nobody should plug or remove it.
- Heating elements and thermostats. Prices vary, and an electric element swap is often cheaper than a new tank. Ask for a written price.
Is there a free estimate, and how do you compare quotes?
Ask the plumber whether the visit and the quote are free, or whether a diagnostic fee applies and is credited against the work. Then line the quotes up on identical terms: unit model and size, gas and vent work, the permit, hauling off the old tank and any warranty paperwork. A low price that skips the gas line is not low.
Through us, a local plumber inspects the heater spot and the gas meter, then writes the price down ahead of the work. The quote form starts that process, and the Harbor Lights Plumbing front page lists the other services.
When is the cheapest time to replace a water heater?
Cold snaps and holidays fill plumbers' schedules, and rush jobs cost more. A planned swap in a quiet week, before the old tank fails, usually avoids emergency premiums and lets you shop for the unit. Signs the tank is near the end include rust-colored hot water, rumbling noises, and moisture around the base.
Common questions
What is the all-in price of a tankless unit?
Guides land between about $1,400 and $5,600 all in. Electric units sit at the low end, gas units at the high end once pipe, vent and permit are counted. Exchanging one tank for another generally costs less, roughly $800 to $2,500.
Is a permit needed for the install here?
Yes. The City of Long Beach asks for a plumbing permit on a residential water heater replacement, and for gas pipe beyond a short run. An inspector checks the work before walls close. The contractor usually applies, so see that the quote says so.
Which costs less to install, gas or electric?
Electric is cheaper when the panel has room, since it avoids venting and gas piping. If the panel needs an upgrade, that advantage can vanish. Gas costs more up front for pipe and vent work but tends to deliver more hot water per minute.
How many hours should the job take?
Expect three to ten hours of labor in published guides, which fills a day for most homes and stretches further when gas pipe, vent or electrical changes are involved. The taps go dry for part of it, so ask the plumber to name a window.
References
- U.S. Department of Energy, Building America, tankless water heaters
- City of Long Beach, permit questions
- City of Long Beach, mechanical, electrical and plumbing code requirements
- Published installed-cost guides for tankless and tank water heaters, anode rods, gas valves and relief valves from several consumer cost sites, checked November 2026
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