What a complete water heater replacement quote includes

By Dana Whitlock. Updated October 13, 2026. How we work.

A good quote names the unit and every code item

The cheapest water heater bid is often the one with a line missing, like the expansion tank. A complete quote says which heater goes in, what comes out, which code-required parts are included, who pulls the permit and what the labor warranty covers. Miss any of those and two bids can't be compared.

Use the list below side by side across bids, and get every line in writing. A verbal "that's included" won't help much when the inspector flags a missing part.

The unit itself

Look for the brand and full model number, beyond a bare "50-gallon gas water heater." The model number unlocks the efficiency rating (UEF), the first hour rating and the tank warranty. DOE's Energy Saver guidance says the first hour rating, the gallons of hot water a full tank can supply in an hour, is printed in the top left corner of the EnergyGuide label as "Capacity (first hour rating)." Compare that figure, and treat tank size as secondary.

• Brand and complete model number
• Fuel: natural gas, propane or electric (and for a heat pump water heater, the electrical circuit it needs)
• Tank size in gallons, or for tankless, the flow rate at your expected temperature rise
• Venting type for gas: atmospheric, power vent or direct vent
• Manufacturer tank warranty length, in years

Removal, permit and inspection

Draining, disconnecting and hauling off the old tank takes real time, and many areas charge a disposal fee. It belongs on its own line or stated as included.

Most cities require a permit to replace a water heater. Escondido, California, for example, states that installing, removing or replacing a water heater without a permit is unlawful under the California Plumbing Code. The quote should say who pulls the permit, whether the fee is included and that the contractor will attend or arrange the inspection. The permit works in your favor. An inspector looks at the venting, gas connection and relief valve piping, the parts you can't easily judge yourself.

Code items that are often left off

These parts depend on where you live and where the heater sits. A quote without them might be fine. Or it might grow on install day. Ask about each.

• Thermal expansion tank: required where the water system has a check valve, backflow preventer or similar closed device. Escondido cites CPC 608.3, and Addison, Texas, requires one at every water heater because its meters include check valves.
• Drain pan: required where a leak would damage the building, such as an attic or upper floor. Escondido's handout calls for a corrosion-resistant pan with a drain of at least 3/4 inch to an approved location. Addison does not allow plastic pans under gas-fired heaters.
• Seismic straps: California requires water heaters to be strapped to resist earthquake motion. Los Angeles requires straps in at least two places, in the upper and lower thirds of the tank, with the lower strap at least 4 inches above the controls, and does not accept plumber's tape on tanks over 40 gallons. Outside California, ask whether your city has its own strapping rule.
• Relief valve and discharge pipe: a new temperature and pressure relief valve comes on the tank, but the discharge pipe often needs redoing. The rule, as InterNACHI summarizes it: full size, no valves or tees, no threads at the end, draining by gravity, ending no more than 6 inches above the floor or a drain.
• Gas connector, shutoff and sediment trap: Escondido's handout requires a listed flexible connector no longer than 6 feet that is not reused from the old appliance, an accessible shutoff within 6 feet, and a sediment trap ahead of the connector.
• Water connections: new supply lines or dielectric fittings, as needed.
• Garage installs: in California, burners and ignition must sit at least 18 inches above the floor unless the heater is listed as flammable vapor ignition resistant, with protection from vehicles.

Venting deserves its own line

On a gas tank heater, the vent connector between the heater and the chimney or flue usually needs new pipe, and the quote should say so. Escondido's handout notes the single-wall connector must slope upward at least 1/4 inch per foot and be fastened with sheet metal screws.

Watch for the orphaned water heater. Replace a furnace with a high-efficiency model that vents out the side wall, and the water heater may be left alone in a masonry chimney sized for two appliances. A water heater alone often can't pull enough draft up that bigger flue, and a metal liner sized for the heater is the usual fix. Liners cost real money. Put it in the quote so it doesn't show up later as a change order.

Moving from a standard tank to a power vent, direct vent or tankless unit changes the venting entirely and may add an electrical outlet. Those parts should be itemized.

Warranty and timing

Get the labor warranty in writing. Tank warranties come from the manufacturer and often cover the part alone, leaving the labor to swap it on you.

• Labor warranty: how long the contractor stands behind their own work, separate from the manufacturer's tank warranty.
• Who registers the product with the manufacturer, if registration is required for full coverage.
• Start date and how long you'll be without hot water. Same-day replacement is common for a like-for-like tank.
• Payment terms, and whether the price is fixed or can change once the old unit is out.

Red flags in a water heater quote

• No model number, just a size and a price.
• "Permit not needed" in a city that requires one, or an offer to skip it for a discount.
• A price far below the range above with no explanation. Check what's missing: permit, haul-away, expansion tank or a smaller unit.
• Pressure to upsize to a much larger tank or switch to tankless with no reason tied to your household's hot water use.
• No mention of venting on a gas unit, especially if your furnace was recently replaced.
• A relief valve discharge pipe that ends in threads, has a valve in it, or stops a foot up the wall.
• Cash only, or a large deposit before any work.