We install plenty of tankless systems, but we won't talk you into one if a high-efficiency tank is the smarter call for your situation. The honest decision matrix is further down this page.
What tankless actually does
A tankless water heater (also called on-demand or instantaneous) doesn't store hot water. When you turn on a hot tap, cold water flows through the unit, a flame (gas) or heating element (electric) fires up, and water comes out hot. When you turn the tap off, the unit shuts down. No tank, no standby heat loss, no waiting for a tank to reheat.
The practical effect: you don't run out of hot water. Run two showers, the dishwasher, and the washing machine at the same time? The unit just keeps heating water as fast as you can use it (within its rated flow capacity, which is what makes sizing critical).
The honest tankless decision matrix
Here's the no-sales-pitch version of when tankless is the right call:
Get tankless if these are true
- You have 3 or more bathrooms or 4+ people in the household
- You've run out of hot water at least a few times — long showers, big loads, simultaneous demand
- You have natural gas service at or near the install location
- You have a water softener or are willing to install one (essential in Oklahoma)
- You're staying in the house at least 7 more years
- You want to free up closet or garage space the tank currently occupies
- You can absorb the $3,800-$5,500 upfront cost (or finance it)
Stick with a tank if these are true
- You have 1-2 bathrooms and a household of 2-3 people
- You're selling within 5-7 years (you won't recoup the install premium)
- You have only electric service at the heater location (electric tankless can't match gas performance for whole-home use)
- You won't commit to annual descaling — without it, tankless units fail prematurely in Oklahoma's hard water
- You want the lowest possible upfront cost
If you checked 4+ boxes in the first list above and zero in the second, tankless is right for you. If you're mixed, a high-efficiency 50-gallon tank is usually the better answer. We'll give you a real recommendation during the free in-home assessment.
What tankless installation costs in OKC
Standard install scenarios
- Gas tankless replacing existing gas tank (same location, gas line OK): $3,800–$5,200
- Gas tankless with gas line upsize required: $4,500–$5,800
- Conversion from electric to gas tankless (new gas service + venting): $5,500–$7,500
- Electric tankless (point-of-use, e.g. for a guest bath): $650–$1,400
- Electric tankless (whole-home, requires significant electrical upgrade): $2,500–$4,500
Add-ons commonly included
- Recirculation pump (for instant hot water at distant fixtures): +$485–$685
- External condensate neutralizer: +$165–$245
- Whole-home water softener (highly recommended for tankless in OK): +$1,500–$2,400 — see softener page
- Annual descaling service contract: $185–$245/year
Federal tax credits
Currently the federal Energy Efficient Home Improvement Credit covers 30% of the cost up to $600 for qualifying tankless water heaters (gas units that meet ENERGY STAR Most Efficient criteria). We provide the documentation needed for your tax filing. This is in addition to the regular install pricing.
Brands we install
Rinnai
Our most-installed brand. Made in Japan, exceptional reliability, great service network in Oklahoma. The RU series (RU160, RU180, RU199) is our default recommendation for most OKC-metro homes. 15-year heat exchanger warranty.
Navien
Korean-built, very efficient (some of the highest UEF ratings on the market), often slightly less expensive than Rinnai for comparable capacity. Excellent for new construction. 15-year heat exchanger warranty.
Rheem
Made in the USA, wider availability of replacement parts, good middle-ground option. Their condensing tankless models (RTGH series) are our go-to for budget-conscious tankless installs. 12-15 year heat exchanger warranty.
Brands we generally avoid
Honestly, the major brands above are all good. We won't install off-brand budget tankless units imported through online retailers — manufacturer support is poor, parts are hard to source, and warranty claims often go nowhere.
Sizing — why this matters so much
Tank heaters are sized in gallons (40, 50, 75). Tankless units are sized in flow rate — gallons per minute (GPM) at a given temperature rise. This trips up homeowners constantly because the unit size needed depends on:
- Your incoming groundwater temperature (50°F in winter in OK, 75°F in summer)
- How hot you want it (120°F is standard)
- How many fixtures might run at once
The temperature rise needed in an Oklahoma winter (120°F minus 50°F = 70°F rise) requires a much higher BTU unit than the same flow rate in summer. Most undersized tankless installs are the result of someone reading "9 GPM" off the box without checking what temperature rise that's rated for.
Our sizing process: we measure your incoming water temperature, count fixtures and their realistic simultaneous-use scenarios, and pick a unit that handles peak demand in winter, not summer. That's the difference between "endless hot water" and "lukewarm shower in January."
Why annual descaling is non-negotiable in Oklahoma
Oklahoma water averages 8–12 grains per gallon of hardness. Calcium and magnesium drop out of solution inside the tankless heat exchanger as the water heats. Over months, scale coats the inside of the exchanger like the scale on your shower head — except now it's on the part transferring heat. Efficiency drops. The unit fires longer to make the same hot water. Eventually it shuts down on overheating fault, or worse, the heat exchanger fails.
Descaling is the solution. We isolate the unit, flush it with food-grade descaling solution for 45-60 minutes, rinse, and put it back in service. Done annually, your tankless lasts its full 20-year design life. Skip it, and you'll be calling us in year 8 with a failed unit.
The best long-term solution is to install a water softener ahead of the tankless. Softened water dramatically extends descaling intervals (every 2-3 years instead of annually) and adds years to the unit's life.
How the install actually goes
- Free in-home assessment (30–45 min) — we measure incoming water temp, evaluate your gas line and venting options, check electrical, and write you a flat-rate quote with two or three unit options.
- Order and schedule — most units arrive in 2–4 business days; we schedule install around your availability.
- Install day (4–8 hours) — remove old tank, mount new tankless, run any needed gas line upsizing, install venting (typically PVC for condensing units or stainless steel for non-condensing), connect water and electric, prime and pressure-test, configure and commission.
- Walkthrough — we show you the unit's controls, error code reset, isolation valves for future descaling, and answer any questions.
- One-year follow-up — we'll reach out near the one-year mark to schedule your first descaling.
FAQ — Tankless in OKC
A gas tankless replacing an existing gas tank in the OKC metro typically runs $3,800–$5,200 all-in. Converting from electric to gas tankless (requires new gas service and venting) is $5,500–$7,500. Electric tankless: $2,200–$4,500. Pricing includes unit, install, code updates, and old heater disposal.
Tankless units last 15–20 years when properly maintained — almost twice as long as a tank heater. The key is annual descaling, which is critical in Oklahoma's hard water. Skip the descaling and you'll get 8–10 years, which negates the cost advantage of going tankless.
Tankless usually pays off within 7–9 years if you have 3+ bathrooms, natural gas already at the location, a water softener (or plan to install one), and are staying in the home long-term. For smaller homes or short-term ownership, a high-efficiency tank is usually the better value.
Tankless units are sized by flow rate (GPM at a given temperature rise) — not gallons. A typical 4-bathroom Oklahoma home needs a unit capable of 8–9 GPM with a 70°F temperature rise. We measure your incoming water temperature, calculate peak demand based on simultaneous fixture use, and size to actual need — not whatever the brochure recommends.
No. Tankless installations require specific gas line sizing (most existing gas lines are too small for tankless), proper venting (special stainless steel category III or IV vent material), condensate drainage, and code-compliant electrical. Manufacturer warranties are voided by unlicensed installation. Get a licensed plumber.
It will, if you ignore it. Hard water deposits scale on the heat exchanger and within a few years efficiency drops and units fail. With annual descaling (a 90-minute service for $185–$245) and ideally a water softener, tankless units last their full 20-year design life in Oklahoma. Without it, plan on 8–10 years.
Call the family
Free in-home assessment, honest sizing, no high-pressure sales. We'll tell you whether tankless makes sense for your house — and if it doesn't, what the better answer is.