Water heater replacement

What replacement costs, by type

Price differences between quotes usually come from what is included rather than the heater itself. Ask whether the quote covers the permit, haul-away, a new expansion tank, new flex connectors, a drain pan and any venting changes. Two quotes that look $600 apart are often the same job with different line items.

What drives the price up

• Location. An attic install with a pull-down ladder, a crawlspace, or a tight closet takes longer and sometimes needs two people.
• Code upgrades. Thermal expansion tanks, seismic straps (required in California and other quake zones), drain pans, and raised stands for garage gas heaters are commonly required when a heater is replaced.
• Venting. Moving from an old atmospheric gas heater to a high-efficiency or power-vent model can mean new vent pipe or a new wall penetration.
• Gas line size. Tankless conversions often need a larger gas line from the meter.
• Electrical. Heat pump heaters and electric tankless units may need a new circuit or a panel upgrade.
• Permit fees. These vary from about $50 to a few hundred dollars depending on the city.

Tank, tankless or heat pump?

Tank heaters cost the least up front, are the quickest to install, and work well for most households. A 50-gallon tank suits three to four people. Expect 8 to 12 years of life.

Tankless units provide endless hot water and last longer (often 15 to 20 years), but cost more to install, need annual descaling in hard water, and require a properly sized gas line. They make the most sense in homes that run out of hot water regularly or have little space.

Heat pump water heaters move heat from the surrounding air into the tank instead of making it with resistance coils. They use a fraction of the electricity, but they need room around them (they cool the space they sit in) and do best in garages or basements that stay above about 40°F.

Our tank vs tankless cost guide compares the total cost over ten years, including energy, maintenance and expected life.

How a replacement goes

1. Sizing. The plumber confirms household size, peak use and fuel. Going one size up from a tank that always ran short is common.
2. Shutdown and drain. Gas or power off, cold supply closed, the old tank drained through a hose.
3. Removal. Disconnecting water, gas or electric and venting, then hauling the old heater out.
4. Install. New heater set level on a pan or stand, connections made with new fittings, T&P discharge piped to an approved location, straps and expansion tank added where required.
5. Fill, purge and light. Tank filled with a hot faucet open to bleed air, then gas lit or power restored.
6. Testing. Leak check on gas and water, draft test on the venting, temperature check at a faucet.

A straight tank-for-tank swap usually takes two to four hours. Tankless conversions often take most of a day. Many plumbers can do a tank swap the same day you call if they have the size in stock.

Questions to ask before you agree to a quote

• Does the price include the permit, haul-away and disposal of the old heater?
• Will you add an expansion tank, drain pan, straps or a stand, and are those in the price?
• Are you matching my current size and fuel, or recommending a change, and why?
• What warranty does the heater carry, and what warranty do you give on your own labor?
• How soon can you install, and will the house have hot water tonight?

A plumber who answers these clearly and puts them in writing is usually a plumber who will do a clean install. Vague answers on the permit question are a reason to keep calling around.

It also pays to ask about rebates before choosing a model. Many utilities give money back for heat pump or high-efficiency gas heaters, and federal tax credits apply to qualifying heat pump units. The paperwork usually needs the model number and installer's details, so sort it out before the old heater is hauled away.

Getting the size right

Tank size is about peak demand, not household size alone. Look at the first-hour rating on the yellow EnergyGuide label: it tells you how many gallons of hot water the heater can deliver in one busy hour. A household where two people shower back to back while the dishwasher runs needs a higher first-hour rating than one where showers are spread out.

Tankless units are sized by flow rate and temperature rise instead. A unit that delivers 8 gallons per minute in Phoenix, where groundwater is warm, may only deliver 5 in Minneapolis in January. A plumber who works locally sizes for your coldest month.

Permits and inspections

Most cities and counties require a permit to replace a water heater, because the job involves gas, venting, electrical work and a pressure relief device. A licensed plumber normally pulls the permit as part of the job and schedules the inspection. Skipping it can cause trouble when you sell the house or file an insurance claim, so ask whether it is included.

Local rules differ. Some places require expansion tanks on every install; some require earthquake strapping; some limit where a T&P discharge line can end. A plumber who works your area knows the local inspector's expectations.

Signs it is time to replace rather than repair

• Water seeping from the tank body or the bottom seam (leaking water heater).
• Rusty water from the hot side only.
• The heater is past 10 to 12 years and needs a gas valve, a second element, or keeps tripping.
• Loud rumbling that a flush no longer quiets (noisy water heater).
• The household has grown and hot water runs out every day.

Replacing on your own schedule, before a failure, usually costs less than an emergency swap on a Sunday night, and it gives you time to compare options.

Questions people ask