Karen M. had lived in her Plano home for 13 years. The Rheem 50-gallon tank water heater that came with the house was 12 years old — past its expected lifespan. The signs were unmistakable: rust-colored water from the hot tap, a low rumble from the tank that had not been there before, and a small pool of water forming around the base during high-demand mornings.
“I kept thinking it would hold on a little longer,” Karen said. “But every time someone took a long shower, I worried the tank would give out completely. And with two teenagers in the house, long showers are not optional.”
She had already priced out emergency plumber calls — the kind that come when a tank actually ruptures. They ranged from $1,500 for a rush replacement to $3,500+ once you factored in water damage remediation and the premium you pay when you have no choice but to call fast.
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The Situation: A Tank on Its Last Legs
Karen’s water heater was showing every classic warning sign of impending failure. At 12 years old, it had already exceeded the typical 10-12 year lifespan of a traditional tank unit. The rust-colored water indicated corrosion inside the tank. The rumbling sound was sediment buildup reducing efficiency. The pooling water meant the pressure relief valve or the tank itself had begun to leak.
She did not want to be that homeowner dealing with a flooded utility room at 6 a.m. on a Tuesday.
The Solution: A Rinnai Gas Tankless Water Heater
Karen found Plumbing Sniper through their water heater installation cost guide and used the free quote form to connect with a licensed DFW plumber in her area.
The plumber assessed her home’s hot water needs — two full bathrooms, a kitchen, and a washing machine running simultaneously on most mornings — and recommended a Rinnai RU199i natural gas tankless water heater. The unit heats up to 9.8 gallons per minute, enough to run multiple showers and faucets at the same time without the temperature drops she had been experiencing.
The installation included:
- Removal and disposal of the old 50-gallon tank
- Gas line upgrade to support the tankless unit
- New termination vent through the roof
- Permit and city inspection (Plano requires one for water heater replacements)
- Installation of the Rinnai unit with a 12-year heat exchanger warranty
Total installed cost: $3,200
After applying the Atmos Energy SmartChoice rebate for high-efficiency gas tankless units (UEF 0.87+), Karen’s net cost came to $2,900.
Not sure which unit is right for your home? See our Rinnai vs. Navien comparison for a side-by-side breakdown.
The Result
The new Rinnai tankless system was installed in a single day. Within a week, Karen noticed the difference in her monthly natural gas bill.
The old tank unit was costing approximately $480/year in energy costs — running continuously to keep 50 gallons hot even when no one was home. The Rinnai, which heats water only when the tap is open, cut that to roughly $60/year.
Annual energy savings: ~$420
System lifespan: 20+ years (vs. 10-12 years for a traditional tank)
Over the life of the unit, Karen will save roughly $8,400 in energy costs compared to running two more tank water heaters. And because the Rinnai is wall-mounted and roughly the size of a small suitcase, she reclaimed the floor space that held a 300-pound tank for over a decade.
“I wish I had done this years ago. The old water heater had been slowly failing for months — probably losing efficiency the whole time — and I did not even realize how much it was costing me. Now we have endless hot water, I am saving money every month, and I do not have to stress about a tank failure in the middle of winter.”
— Karen M., Plano, TX
The Numbers at a Glance
| Old Tank (50-gal Rheem) | New Tankless (Rinnai RU199i) | |
|---|---|---|
| Lifespan | 10-12 years | 20+ years |
| Annual energy cost | ~$480/year | ~$60/year |
| Hot water supply | 50 gallons (runs out) | On-demand (never runs out) |
| Installation cost | — | $3,200 (before rebate) |
| After Atmos Energy rebate | — | $2,900 net |
| Annual savings | — | ~$420/year |
| 20-year energy savings | — | ~$8,400 |
| Space required | ~18 sq ft floor space | Wall-mounted, ~2 sq ft |
Is a Tankless Water Heater Right for You?
Not every home needs a tankless system. Here is a quick breakdown:
Consider an upgrade if:
- Your current water heater is 8-12+ years old
- You have noticed rust-colored hot water, strange noises, or inconsistent temperature
- Your household regularly runs multiple hot water fixtures at once
- You want to eliminate the risk of a tank rupture and water damage
- You plan to stay in your home for 5+ more years (longer stays = better ROI)
Consider keeping a tank system if:
- Your current water heater is less than 8 years old and performing well
- Your household has modest hot water demand (1-2 people, single bathroom)
- Budget is a primary concern — tank systems run $1,500-$2,500 installed
If you have an older tank showing warning signs, the math favors planned replacement. Emergency replacements typically cost 30-50% more, and water damage from a ruptured tank adds thousands. Learn more about what to budget in our guide to water heater installation costs and see what DFW plumbers charge per hour in 2026.
How Plumbing Sniper Helps
Plumbing Sniper connects homeowners with licensed, vetted plumbers in their area. Every contractor in the network is screened for licensing, insurance, and customer reviews. You get upfront pricing before any work begins, and the entire process starts with a free quote — no commitment required.