How to replace a water heater: the full process, from decision to first hot shower
Replacing a water heater is one of the most predictable major plumbing jobs a Bellevue homeowner will do — predictable because water heaters fail on a known schedule (10 to 12 years for tank, 15 to 20 for tankless), and the replacement process is well-defined. The decision is usually forced by a leaking tank or cold water, but catching it a year or two early — before the emergency call — gives you time to consider a heat-pump upgrade and the $1,000 PSE rebate that goes with it. This guide walks through when replacement beats repair, how to choose the right size and type, what happens on installation day, and the full Bellevue cost picture.
Last reviewed: 2026-06-13
When to replace vs. repair a water heater
Replace if the tank is leaking (no repair exists for a failed tank), if the unit is over 10 years old and having its second problem, or if repair cost exceeds 50% of replacement. Repair if the unit is under 8 years old and the problem is a single failed component — element, thermostat, anode rod, or pressure-relief valve.
A leaking tank is the clearest case: water pooling under the unit means the inner steel tank has failed, and no repair restores a breached tank. Drain it, replace it. A leak at a fitting, valve, or connection is different — those are repairs, and they're worth doing if the tank itself is sound.
Age is the second filter. The average gas tank lasts 8 to 12 years; electric tank, 10 to 15; tankless, 15 to 20. If the unit is under 8 years old and having its first issue, repair almost always wins on cost. If it's 10-plus and having its second issue, replacement wins — not because the repair won't work, but because the next failure arrives quickly and you pay the service call twice. The math tips faster than most people expect.
The 50% rule is the practical guide for the middle cases: if the repair quote is more than half the cost of a new unit installed, replace. A $450 element swap on a 7-year-old $800 tank? Repair. A $600 gas valve on an 11-year-old $1,200 tank? Replace. The guide to water heater not heating walks through each symptom and whether the fix is component-level or terminal.
One proactive case worth flagging: if your tank is 8 to 10 years old and functioning but you're planning a kitchen remodel, bathroom addition, or HVAC project in the next two years, replace now rather than waiting for an emergency. You control the timing, the truck visit is already happening, and you avoid paying a crisis premium. If electric resistance is the current fuel source, this is also the window to evaluate a heat-pump water heater — the $1,000 PSE rebate and federal 30% tax credit stack, and the math on those incentives is in our heat pump water heater guide.
Picking the right replacement: size and type
For tank replacements, match the existing gallon size to household size — 40 gallons for 1 to 2 people, 50 gallons for 3 to 4, 65 to 80 for 5-plus. For type, the 2026 decision is: electric resistance (cheapest to buy), heat pump (most efficient, $1,000 PSE rebate), or gas tankless (high efficiency, no tank). Tankless electric is rarely right for Bellevue's electrical service.
First-hour rating matters more than tank size for real-world performance, but gallon size is the proxy everyone uses and it works well enough: 40-gallon for a 1 to 2 person household, 50-gallon for 3 to 4, 65 to 80 for 5 or more or a household with a large soaking tub. Upsizing a tank by one tier (40 to 50, 50 to 65) costs roughly $50 to $150 more and is worth it if morning hot water has ever run out.
Type choice in 2026 comes down to three realistic options for most Bellevue homes. Standard electric resistance tank: lowest purchase price ($600 to $900 installed), cheapest to replace, works in any space, no venting. Heat pump water heater: $1,000 more upfront, $1,000 PSE rebate, 30% federal tax credit — net cost is often similar to or less than electric resistance after incentives, with energy savings of $300 to $500 per year. Requires 700 cubic feet of unconditioned space (basement, garage, utility room) and 7 feet of ceiling. Gas tankless: $2,000 to $3,500 installed, endless hot water, space-saving, 20-year lifespan — but requires gas line capacity check and venting work. The full comparison with Bellevue-specific cost math is in tankless vs. tank water heaters.
Tankless electric whole-house is usually not the right choice for the Pacific Northwest. It requires 150 to 200 amp service upgrades in most homes and draws enormous instantaneous load — the electrical panel upgrade alone often costs more than the unit. Point-of-use electric tankless (under a sink, in a remote bathroom) is fine; whole-house electric tankless rarely pencils out here.
Fuel switching — gas to electric or electric to gas — adds cost but is sometimes worth it. Electric to heat pump is the common upgrade: uses the existing 240V circuit, no gas line needed, and the rebates make it financially competitive. Gas to electric requires removing the gas line (or capping it and leaving it), which is simpler than adding one. Adding a gas line where none exists runs $400 to $900 for the line and $800 to $1,600 for the unit — total installed cost of $2,000 to $4,000 for a tankless that will outlast two standard tanks.
What happens on water heater replacement day
The job takes 2 to 4 hours for a like-for-like tank swap, 3 to 6 for a tankless or heat pump. The plumber drains and disconnects the old unit, removes it, sets the new one, connects supply lines and the relief valve, sets temperature to 120°F, and lights or powers the new unit. Permits are pulled for gas, venting, or panel work.
A standard like-for-like electric tank replacement runs 2 to 3 hours: shut off power and cold supply, connect drain hose and empty the tank, disconnect wiring and supply lines, remove old unit, set new unit in place, reconnect wiring and supply lines, install new pressure-relief valve and discharge tube, fill tank, restore power, and confirm the thermostat is set to 120°F. The water is off for roughly 45 minutes of that time. Same-day hot water is standard.
Gas replacements add 30 to 60 minutes: the gas line is shut off at the appliance valve, disconnected, reconnected to the new unit with new flexible connectors (required by code — old flex connectors are not reused), and leak-tested before relight. Venting is inspected and reused if code-compliant; if the draft hood sizing changed with the new unit, vent pipe may need adjustment. A City of Bellevue permit is required for gas work and for any new gas appliance installation — it's pulled before the job and the inspection happens within a few days.
Heat pump water heater installations take 3 to 5 hours because the unit is physically larger (5 feet tall versus 4 feet for a standard tank), the condensate drain line must be routed (the unit pulls moisture from the air as it runs), and the electrical connection is verified against the existing 240V circuit rating. Some installations require a dedicated circuit if the existing one is undersized — that's a $200 to $400 add-on. The space and airflow requirements are confirmed in the pre-install assessment.
On removal: in Bellevue the old tank is typically hauled away by the installing plumber and dropped at a metal recycler. If you're DIYing the installation, Bellevue Recycles at the Eastgate facility takes water heaters, or Republic Services can schedule a bulk pick-up. A full tank weighs 150 to 400 pounds depending on size — drain it fully before moving. The process for draining is the same whether you're DIYing or prepping for the plumber: attach a hose to the drain valve at the bottom, run it to a floor drain or outside, open the pressure-relief valve at the top to let air in, and open the drain valve.
Bellevue water heater replacement cost in 2026
A standard 50-gallon electric tank replacement in Bellevue runs $950 to $1,450 installed. Gas tank replacement runs $1,100 to $1,600. A heat pump water heater runs $2,000 to $2,800 installed — minus $1,000 PSE rebate and up to $600 federal tax credit, net cost as low as $400 to $1,200. Tankless gas runs $2,400 to $3,800.
Electric tank (50-gallon, like-for-like): $950 to $1,450 installed flat-rate. This covers unit, supply lines, new P&T valve and discharge tube, haul-away, and labor. No permit required for electric tank like-for-like. If the circuit is the right amperage (30A for most standard tanks, 30A to 40A for heat pump), no electrical work is needed.
Gas tank (40 to 50-gallon): $1,100 to $1,650 installed. Premium includes the gas reconnection labor, new flexible gas connectors (code requirement), vent inspection, and City of Bellevue gas permit. If the draft diverter or vent sizing needs adjustment, add $100 to $250.
Heat pump water heater (50-gallon, Rheem ProTerra or Rheem Prestige, Ruud, or AO Smith): $2,000 to $2,800 installed. After the $1,000 PSE rebate (applies to both standard and Efficiency Boost income-qualified tiers) and the federal 25C tax credit (30% of unit cost, approximately $400 to $600 for 2026), the net out-of-pocket cost drops to $400 to $1,800 depending on tax situation. The PSE rebate requires a 30-day post-installation submission window — detailed process in our heat pump water heater guide.
Tankless gas (Navien, Rinnai, Rheem): $2,400 to $3,800 installed. The wide range reflects venting complexity — a direct-vent concentric install through an exterior wall is simpler than routing through an existing vent chase, and homes with no existing gas venting near the installation point cost more. Add $400 to $900 if a new gas line must be run from the meter. The detailed cost and efficiency breakdown for tankless is in tankless vs. tank water heaters in Bellevue.
Sources
Every fact in this guide cites a verifiable public source. If you find a number we got wrong, email dispatch@bellevueplumberpro.com.
- PSE — Water heater rebates (Efficiency Boost program)
- Energy.gov — Heat pump water heaters: efficiency and sizing
- City of Bellevue — Plumbing permits and gas appliance requirements
- ENERGY STAR — Certified water heater product list
Need help with this in your home? See our Water heater repair and replacement in Bellevue page for pricing, our diagnostic process, and how same-day service works across the Eastside.
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