Tankless water heaters are everywhere in new Williamson County builds, and for good reason: endless hot water, half the footprint, and 20+ years of useful life. But not every home is a tankless candidate. Here's what Brentwood and Franklin homeowners need to know.
How tankless actually works
Instead of keeping 50 gallons hot 24/7, a tankless unit fires up only when you turn on a hot tap. Cold water flows through a heat exchanger, gets heated on demand, and out comes hot water for as long as you want it. No standby losses. No tank to leak in your garage.
When tankless is the right call
- Your tank failed. Replacement decision point - pay 2x for tankless, get 20 years instead of 10.
- You run out of hot water. Family of four, two showers running, dishwasher? A 50-gallon tank loses that fight.
- You want the garage space back. Tankless mounts on a wall, frees up 6+ sq ft.
- You're going long-term. Payback on the upcharge is 8-12 years. Plan to stay.
When to stay with a tank
- Selling in under 5 years. You won't recoup the upgrade in the sale price.
- Tight gas supply. Tankless units need a 3/4" gas line minimum and a high BTU rating. Older Brentwood homes sometimes need a line upgrade.
- Hard water and no softener. Williamson County water is moderately hard. Tankless without annual descaling will scale up fast.
What it costs in Brentwood and Franklin
- Tank replacement (50 gal gas): $1,800 - $2,600 installed.
- Standard tankless install: $3,800 - $5,200 installed.
- Tankless with gas line upgrade: $4,800 - $6,500 installed.
- Tankless with recirculation pump: add $600 - $900 (hot water at the tap in 5 seconds).
Brands we install
Rinnai and Navien dominate the tankless market and earn it. Both run 15-20 years with annual descaling. We avoid contractor-only brands you can't get parts for in 10 years.
The annual maintenance nobody talks about
Tankless units need to be descaled with vinegar or a citric acid flush once a year in our water. Skip it and you'll lose efficiency, then capacity, then the heat exchanger. It's a 45-minute service and we include it on Priority Service memberships.
Considering a tankless install? Call (615) 254-6283 for a free in-home quote.