Thinking about switching to a tankless water heater? You are not alone. Tankless systems are growing in popularity because they deliver hot water on demand, take up less space, and can last 20 or more years with proper maintenance. But the upfront tankless water heater installation cost is higher than a traditional tank, so it is important to understand what you are paying for before committing. For professional assistance, contact our water heater replacement team.
This guide breaks down everything that affects the price, from the unit itself to labor, permits, and potential upgrades your home may need.
Average Tankless Water Heater Installation Cost
For most homeowners, the total installed cost of a tankless water heater falls in this range:
| Type | Unit Cost | Installation Labor | Total Installed Cost |
|---|---|---|---|
| Electric tankless (whole-house) | $500 – $1,500 | $500 – $1,500 | $1,000 – $3,000 |
| Gas tankless (whole-house) | $1,000 – $3,000 | $1,500 – $3,500 | $2,500 – $6,500 |
| Point-of-use electric (single fixture) | $100 – $500 | $150 – $500 | $250 – $1,000 |
Gas tankless water heaters cost more to install because they require venting, a gas line connection (possibly an upgrade), and combustion air supply. Electric models are simpler to install but may require an electrical panel upgrade.
Factors That Affect the Price
1. Gas vs. Electric
This is the biggest cost factor. Gas units produce more hot water per minute (higher flow rate) and are better for larger households, but they need:
- A dedicated gas line (possibly a larger diameter line than your current tank heater uses)
- Stainless steel or Category III venting to the exterior
- Condensate drain line (for condensing models)
Electric units are cheaper to buy and install but may require a 200-amp electrical panel and dedicated circuits.
2. New Installation vs. Replacement
Replacing a tankless unit with a newer tankless is straightforward because the gas line, venting, and electrical are already in place. Expect to pay on the lower end of the range.
Switching from a tank to tankless costs more because the installer needs to:
- Remove the old tank unit
- Reroute or upgrade the gas line
- Install new venting
- Possibly upgrade electrical
- Cap the old connections
3. Flow Rate Needs (GPM)
Tankless units are sized by gallons per minute (GPM). The more hot water you need simultaneously, the larger (and more expensive) the unit:
- 1–2 GPM: Single fixture (one shower or one sink) — Point-of-use unit
- 5–7 GPM: Small to mid-size household (2–3 bathrooms) — Mid-range whole-house unit
- 8–11 GPM: Large household (4+ bathrooms, multiple simultaneous uses) — High-end whole-house unit
4. Permits and Inspections
Most cities in Orange County and the Inland Empire require a permit for water heater installation. Permit costs typically run $75 to $300 depending on the municipality. A licensed plumber handles the permit process as part of the installation.
5. Location in the Home
Tankless units are compact and wall-mounted, which means they can go in garages, utility closets, or even mounted on an exterior wall. However, if the installation location is far from existing gas and water lines, additional piping adds to the cost.
6. Brand and Quality
Popular brands and their typical unit costs:
| Brand | Type | Typical Unit Cost |
|---|---|---|
| Rinnai | Gas / Electric | $1,000 – $2,500 |
| Navien | Gas | $1,200 – $2,800 |
| Noritz | Gas | $900 – $2,200 |
| Rheem | Gas / Electric | $600 – $2,000 |
| EcoSmart | Electric | $300 – $800 |
Tankless vs. Tank Water Heater: Cost Comparison
Is a tankless water heater worth the higher upfront cost? Here is a side-by-side comparison:
| Factor | Tank Water Heater | Tankless Water Heater |
|---|---|---|
| Upfront installed cost | $1,200 – $3,500 | $2,500 – $6,500 |
| Lifespan | 8 – 12 years | 20+ years |
| Annual energy cost | $400 – $600 | $200 – $400 |
| Energy savings | Baseline | 24% – 34% more efficient |
| Space required | Large (floor space) | Small (wall-mounted) |
| Hot water supply | Limited by tank size | Unlimited on demand |
Over a 20-year period, a tankless system typically saves $2,000 to $4,000 in energy costs, which can offset or exceed the higher installation price. For a deeper comparison, see our guide on tankless vs. tank water heaters.
Need professional help? Learn more about our water heater repair in Orange County.
Additional Costs to Watch For
- Gas line upgrade: $200 – $1,500 if the existing line is too small
- Electrical panel upgrade: $1,000 – $2,500 for a new 200-amp panel (electric tankless)
- Venting installation: $200 – $1,000 for new stainless steel venting
- Water softener: $500 – $1,500, recommended in hard water areas like parts of Orange County to extend the life of the unit
- Annual maintenance flush: $100 – $200 per year (recommended to prevent scale buildup)
How to Save on Tankless Water Heater Installation
- Get multiple quotes — Prices vary significantly between contractors. Get at least three written estimates.
- Check for rebates — SoCalGas and local utility companies occasionally offer rebates for high-efficiency water heaters.
- Choose the right size — Oversizing wastes money. A professional can calculate the exact GPM your household needs.
- Bundle work — If you need other plumbing work done (like a leaking water heater removal), bundling saves on labor.
- Ask about financing — Many plumbing companies offer payment plans for larger installations.
Frequently Asked Questions
Is a tankless water heater worth the investment?
For most homeowners, yes. The combination of energy savings ($150 to $200 per year), longer lifespan (20+ years vs. 10 to 12 years for tanks), and unlimited hot water makes tankless a strong long-term investment. The payback period is typically 6 to 12 years.
How long does tankless water heater installation take?
A straightforward replacement takes 2 to 4 hours. A new installation (switching from tank to tankless) may take 4 to 8 hours if gas line or venting work is required.
Can I install a tankless water heater myself?
It is not recommended. Gas tankless installations require a licensed plumber for the gas connections and a permit in most California cities. Improper installation can void the warranty and create safety hazards including carbon monoxide risk.
What size tankless water heater do I need?
The size depends on two factors: the temperature rise needed (groundwater temperature vs. desired output temperature) and peak simultaneous GPM demand. In Southern California, where groundwater temperatures are moderate (60 to 65 degrees F), a 7 to 9 GPM gas unit handles most 2 to 3 bathroom homes.
Get a Tankless Water Heater Installation Quote
911 Drain Lines & Plumbing installs and services all major tankless water heater brands throughout Orange County and the Inland Empire. Our licensed plumbers will assess your home, recommend the right unit, and provide a transparent, upfront quote with no hidden fees.
Call (714) 746-7611 to schedule a consultation or request an estimate.
