Water Heater Buyer's Guide for New Hampshire Homeowners

Replacing a water heater is a decision most NH homeowners make once or twice in their lifetime. The right choice depends on your current fuel, available space, hot water demand, and rebate eligibility. This guide walks through the four main residential water heater types, the decision questions that point to each, and links to deeper posts on every topic.

If your existing water heater is past 10 years old, leaking, making rumbling noises, or producing rusty hot water, the time to plan a replacement is now (not when the tank fails at 2 AM on a Sunday). Read on for the framework.

Step 1: Know when to replace

Before choosing what to install, confirm replacement is warranted. Read: 10 Signs Your Water Heater Is About to Fail.

The short version: most NH water heaters last 8 to 12 years for tanks, 15 to 20 years for tankless, and 10 to 15 years for heat pump water heaters. Past 10 years on a tank, replacement is on the table. Past 12 years, replacement should be planned.

Step 2: Understand the four main options

Traditional storage tank (40 to 80 gallons)

Familiar, lowest upfront cost. Burns gas, propane, or oil; or uses electric resistance.

Pros: low install cost, simple, fast recovery on gas/propane/oil
Cons: standby losses (heating water 24/7), 8-12 year lifespan
Best for: tight budget, high simultaneous demand on gas, replacement-in-kind

Tankless on-demand

Heats water as it flows through the unit. No storage tank, no standby losses. Read: Tankless Water Heaters and Is a Tankless Water Heater Worth It?. Service page: Tankless Water Heater Installation.

Pros: unlimited hot water, 15 to 20 year lifespan, compact wall-mount, no standby losses
Cons: higher upfront cost, may need gas line upgrade, requires annual descaling
Best for: homes with gas/propane service and moderate to high simultaneous demand

Heat pump water heater (HPWH / hybrid)

Electric tank-style heater that uses heat pump technology to extract heat from surrounding air. Read: Heat Pump Water Heater and the related posts around it. Service page: Heat Pump Water Heater Installation.

Pros: roughly 60 to 75 percent lower operating cost than a standard electric tank, NHSaves rebates available, free dehumidification as a byproduct
Cons: needs 700 to 1,000 cubic feet of surrounding space, taller and heavier than standard tanks, generates compressor noise
Best for: homes with existing electric water heating, homes converting from oil or propane DHW, homes with adequate basement space

Indirect water heater (with boiler)

Separate insulated tank connected to your boiler. The boiler heats domestic hot water in addition to space heat. Read: Indirect Water Heater vs Tankless Coil.

Pros: very long lifespan (20+ years), no separate burner or flue, consistent water temperature, no separate fuel consumption beyond boiler
Cons: requires a boiler, higher upfront cost than swapping a tank
Best for: homes with hydronic heat (existing or new condensing boiler), homes that want the boiler to shut down for the summer (paired with a different DHW source)

Step 3: Use the decision tree

Run through the questions in order:

What is your current water heating fuel?

Electric resistance tank: upgrade to a heat pump water heater (HPWH) is almost always the right answer. 60 to 75 percent operating cost reduction.
Natural gas or propane tank: tankless usually wins for high-demand households; high-efficiency gas storage works for moderate demand.
Oil-fired boiler with indirect tank: if the indirect is at end of life, consider replacing the indirect OR adding an HPWH to decouple DHW from the boiler entirely (lets the boiler cycle off in summer).
Boiler with tankless coil: almost always worth switching to an indirect water heater or HPWH. The tankless coil keeps the boiler hot all summer.

What is your peak simultaneous hot water demand?

One or two simultaneous fixtures: almost any option works
Three+ simultaneous fixtures (multiple showers + dishwasher + washer): tankless or a larger HPWH; standard tanks may not keep up
Very high demand (large soaking tubs, multi-head showers): high-output tankless or pair multiple units

How much space do you have?

Tight mechanical closet, no floor space: tankless wall-mount
Standard basement, adequate clearance: any option
Cold or poorly insulated basement: HPWH may struggle below 50°F ambient; verify space stays above 50°F year-round

What incentives apply?

Federal 25C tax credit: expired December 31, 2025. HPWH was the main eligible water heater type.
NHSaves utility rebates: active for qualifying HPWH installations. Amounts vary by utility and income.
Manufacturer rebates: periodically available from Rheem, A.O. Smith, Bradford White, Navien, and others.

Step 4: Cost comparison (rough installed costs)

Type	Installed cost range	Expected lifespan	Operating cost
40 gal gas storage tank	$1,500 - $3,000	8-12 years	Moderate
50 gal electric tank	$1,200 - $2,000	8-12 years	High
Condensing tankless	$3,500 - $6,500	15-20 years	Low
Heat pump water heater	$3,500 - $6,000 (before rebates)	10-15 years	Lowest electric option
Indirect water heater	$2,500 - $5,000	20+ years	Depends on boiler

Numbers are illustrative. Specific costs depend on the unit, gas line upgrades, venting modifications, electrical work, and rebates that apply.

Step 5: Brand selection

Major residential water heater brands carried by A.J. LeBlanc Heating include:

Rheem (ProTerra for HPWH; gas and electric storage tanks)
A.O. Smith (Voltex for HPWH; full storage tank lineup)
Bradford White (AeroTherm for HPWH; storage tanks)
State (Premier and Patriot lines; HPWH)
Navien (NPE tankless and NCB combi boilers)
Rinnai (tankless)
HTP SuperStor (indirect tanks)

See the full list on our manufacturers page.

Step 6: Maintenance plan

Once installed, every water heater needs ongoing care. Read: What Maintenance Does a Water Heater Need?

Headline items:

Annual tank flushing for storage units
Anode rod replacement every 3 to 5 years for tanks. Also read: Why Your Water Heater Has an Anode Rod
Annual T&P valve testing for all tanks
Annual descaling for tankless units
Air filter check for HPWH (most units have a small filter that should be cleaned every few months)

What to do next

Walk through the decision questions above for your specific home
Confirm rebate eligibility through NHSaves and your utility
Schedule an in-home consultation with a licensed plumber
Get a written estimate that includes equipment, install labor, permits, and any incidental work (gas line, venting, electrical)

Schedule a water heater consultation

For water heater replacement or installation in southern New Hampshire, contact A.J. LeBlanc Heating. Browse related service pages: Water Heaters, Tankless, Heat Pump Water Heaters. Serving New Hampshire families since 1928.

Frequently Asked Questions

How long does a water heater last in NH?

Tank: 8 to 12 years. Tankless: 15 to 20 years. Heat pump water heater: 10 to 15 years. Indirect with a boiler: 20+ years. Maintenance significantly affects all of these numbers.

Is a heat pump water heater really worth the extra cost?

For homes with existing electric water heating, yes, almost always. The operating cost savings (60 to 75 percent) typically pay back the upfront premium within 3 to 5 years, especially with NHSaves rebates.

Will a tankless water heater really save money?

Yes, but the savings are modest (typically 15 to 25 percent over a tank). The real value comes from unlimited hot water, longer lifespan, and recovered floor space.

Can I keep my boiler making hot water if I get a new HPWH?

You can, but the HPWH is usually more efficient. Adding an HPWH typically means decoupling the boiler from DHW entirely, which lets the boiler stay off all summer (substantial seasonal fuel savings).

What is the cheapest water heater to install?

A standard electric tank water heater is usually the lowest upfront cost. However, it has the highest operating cost. For most homes, the right comparison is total cost over the unit's lifespan, not just the install bill.