8 Ways to Save on Tankless Water Heater Installation in 2026
Cutting $500 to $2,000 from a tankless install is realistic if you plan ahead. Here are the eight tactics that produce the biggest savings, with the federal 25C tax credit gone for 2026 installs.
The single biggest 2026 update: the federal 25C Energy Efficient Home Improvement Credit expired December 31, 2025. State and utility rebates are now the main incentive route. Combine three or more of the tactics below to recover $500 to $2,000.
Apply for state and utility rebates
$50 to $300 per installation in 15+ states. The top 2026 incentive route.
Since the 25C federal credit expired Dec 31, 2025, state and utility rebates are the main 2026 incentive. California (SoCal Gas $100 to $200, PG&E $100 to $150, SMUD $100), Massachusetts (MassSave $200 to $300), New York (NYSERDA $100 to $250), Washington (PSE $100 to $200), Oregon (Energy Trust $100 to $200), Maryland (BGE $75 to $150). Most require ENERGY STAR certification. Apply within 60 to 90 days of installation.
Get three quotes, not one
Same job, same brand: quotes vary 40 to 60% between local plumbers.
When requesting quotes, give every contractor the same exact specification: brand, model number, BTU rating, venting type, who supplies the unit, and permit handling. Without this, you cannot meaningfully compare bids. Ask each contractor in writing whether the quote includes a direct swap or a full conversion, what venting work is required, and whether your gas line is adequate. Differences of $1,000 to $2,000 between quotes for the same scope are common.
Choose a direct replacement scenario
Direct swap with compatible infrastructure costs 30 to 50% less than full conversion.
A direct swap (same fuel, compatible gas line, compatible venting route) runs $1,200 to $2,800. A full conversion (new gas line, new venting, panel upgrade) runs $2,500 to $7,000+. Before committing, ask your contractor whether your current setup supports a direct swap. If gas line size is borderline (1/2-inch on a long run), get a second opinion on whether upsizing is truly required.
Time your install for off-peak season
Late spring and early autumn quotes typically beat winter quotes by 10 to 20%.
Plumbers' busiest seasons are mid-winter (failing tank heaters during cold snaps) and mid-summer (peak HVAC demand). Late spring (April to May) and early autumn (September to October) are slower, and contractors are more flexible on price. Emergency winter replacements often pay $500 to $1,500 above off-peak rates. If your existing tank still works, plan the upgrade rather than waiting for it to fail.
Buy the unit separately from the installer
$150 to $400 saved by skipping the plumber's supply markup.
Plumbers markup customer-supplied units 15 to 30%. Buying directly from Home Depot, Lowe's, Amazon, or a plumbing supply house and supplying it to your installer typically saves $150 to $400. Caveats: confirm the model with your installer first, and check whether your manufacturer (Rinnai, Navien) requires a certified installer for warranty. Some installers will not warrant their work on customer-supplied units.
Right-size the unit, do not oversize
Going one tier larger than needed costs $200 to $500 more, with no real benefit.
Oversizing is one of the most common ways homeowners overspend. A 199K BTU unit costs $200 to $500 more than a 150K BTU unit, but if your peak GPM demand is only 7, you do not need 11 GPM capacity. Use our sizing guide to confirm what your home actually needs. Oversized units do not save more energy; they just cost more upfront.
Use a brand-certified installer for premium units
Rinnai and Navien certified installers usually get wholesale unit pricing.
Both Rinnai and Navien recommend (and warrant best with) certified installers. The labour rate is often 10 to 20% higher, but certified installers usually buy units at wholesale prices that retail customers cannot access. The net cost of a certified install is often equal to or lower than a non-certified install with retail-priced units. And the warranty is fully protected.
Pick ENERGY STAR Most Efficient for utility rebates
Required for most utility rebate programmes; usually $50 to $200 better.
Even after the federal credit expired, most state and utility rebate programmes still require ENERGY STAR Most Efficient certification. ENERGY STAR units are typically $100 to $300 more expensive than non-rated units, but the rebate plus operating cost savings recover this in 2 to 4 years. Check your utility's qualifying model list before purchasing.
Stack the Savings: Real-World Examples
| Tactic Stacked | Typical Saving | Effort Required |
|---|---|---|
| State or utility rebate | $50 to $300 | 30 minutes paperwork |
| Buy unit separately | $150 to $400 | 1 hour shopping |
| Three competing quotes | $300 to $1,200 | 1 to 2 weeks |
| Off-peak season install | $200 to $600 | Plan ahead 2 to 3 months |
| Right-size unit (avoid oversizing) | $200 to $500 | 15 minutes calculator |
| Combined total possible | $900 to $3,000 | 5 to 8 hours total |