Tank or tankless: what each costs
A tank heater is the cheaper one to put in. NerdWallet puts a tank swap at $600 to $2,500, and This Old House puts a tank install at $1,200 to $2,300.
Tankless costs more up front. NerdWallet says about $1,400 to $3,900 installed, and This Old House says $1,200 to $3,500.
Costs at a glance
Nationally, replacing a tank water heater costs $600 to $2,500; tankless, $1,200 to $3,900. Idaho's "Existing residential" plumbing permit: $65 per inspection, plus $10 for each additional fixture.
| Job | Typical cost | Sources |
|---|---|---|
| Tank water heater replaced | $600 to $2,500 per job | Sources: [1][2] |
| Tankless water heater installed | $1,200 to $3,900 per job | Sources: [1][3] |
| Plumbing permit, "Existing residential", per inspection | Idaho fee: $65, as of March 28, 2023 | Sources: [4] |
| Plumbing permit, "Existing residential", each additional fixture | Idaho fee: $10, as of March 28, 2023 | Sources: [4] |
- NerdWallet, Water Heater Cost in 2026: DIY or Professional Installation?, updated September 18, 2025.
- This Old House, How Much Does Water Heater Installation Cost? (2026), updated June 17, 2026.
- This Old House, How Much Does Tankless Water Heater Installation Cost?, updated June 12, 2026.
- Idaho Division of Occupational and Professional Licenses, IDAPA 24.39.20, Rules Governing Plumbing, Permit Fee Schedule, updated March 28, 2023.
National ranges and official fees from the sources listed, checked October 2026. These aren't prices from businesses listed on Huck's Guide. Costs in Boundary County can be higher or lower.
NerdWallet says electric, propane and natural gas heaters start at similar prices. The price can climb when the job needs a new gas line or changes to the electric system.
How long a water heater lasts
The two guides differ a little. NerdWallet says a tank lasts about 10 to 15 years with care, and This Old House says 8 to 12. For tankless, NerdWallet says about 20 years and This Old House says 15 to 20.
This Old House says to think about replacing a water heater when it reaches 10 years old, gives rusty water, or can't keep up. Water pooling around the base and repeat repair visits in one year are other signs it lists.
Water heaters around here
Here, the state handles plumbing permits and inspections.
Idaho's plumbing rules set the permit fee for an "Existing residential" permit at "$65 per inspection plus $10 for each additional fixture."
Source: IDAPA 24.39.20, Rules Governing Plumbing. Existing home permit fee checked in the rule's fee schedule, Oct 28, 2026.
Ask whether the permit and its inspection fees are part of the quote.
DOPL's inspector list sets plumbing inspection days for Bonners Ferry, Moyie Springs, Naples, Porthill, Eastport and Copeland: Monday, Wednesday and Friday.
Source: Idaho DOPL, Inspector List with Schedules. Plumbing inspection days checked on DOPL's August 2026 inspector list, Oct 28, 2026.
For a gas water heater, the fuel source depends on where you live. Avista's natural gas tariff, filed with the Idaho Public Utilities Commission, names Bonners Ferry in its gas service area, and no other Boundary County town.
Source: Avista Utilities natural gas tariff, Idaho Public Utilities Commission. Towns in the gas service area checked on the tariff's rate area sheet, Oct 28, 2026.
What can add to the price
- Switching fuel. This Old House says going from electric to gas means new gas lines, and electric conversions may need new wiring and a panel upgrade.
- Going tankless on electric. This Old House says most tankless units need a lot of dedicated electrical service, which can mean panel work.
- Propane tankless. This Old House says to plan for a propane tank of at least 100 gallons and regular deliveries.
- Moving the heater. NerdWallet says relocating a water heater adds to the work and the cost.
Who handles each part
- The swap: a licensed plumber. See the local plumbing businesses, and look up any license on DOPL's public license search.
- Natural gas service in Bonners Ferry: Avista Utilities.
- A propane tank and deliveries: the local propane businesses.
- Panel or wiring work for an electric heater: the local electricians.
Ask before you hire
Five questions for anyone quoting a new water heater. Tick them off as you go.
Sources
| Source | What was checked | Last checked |
|---|---|---|
| NerdWallet, water heater cost guide (updated Sept. 18, 2025) | Tank and tankless ranges, life spans, fuel note and relocation note checked | Oct 28, 2026 |
| This Old House, water heater installation guide (updated June 17, 2026) | Tank range, install time, life span, signs to replace, fuel switch and garage notes checked | Oct 28, 2026 |
| This Old House, tankless installation guide (updated June 12, 2026) | Tankless range, life span, power needs and propane tank size checked | Oct 28, 2026 |
| Idaho DOPL, Plumbing Frequently Asked Questions | Permit rule checked on DOPL's plumbing questions page | Oct 28, 2026 |
| IDAPA 24.39.20, Rules Governing Plumbing | Existing home permit fee checked in the rule's fee schedule | Oct 28, 2026 |
| Idaho DOPL, Inspector List with Schedules | Plumbing inspection days checked on DOPL's August 2026 inspector list | Oct 28, 2026 |
| Idaho DOPL, Plumbing | Public license search link checked on DOPL's plumbing page | Oct 28, 2026 |
| Avista Utilities natural gas tariff, Idaho Public Utilities Commission | Towns in the gas service area checked on the tariff's rate area sheet (Sheet C, effective July 9, 1999) | Oct 28, 2026 |
| Avista Utilities | Natural gas service checked on Avista's home page | Oct 28, 2026 |