water heating · TN LLP #5045 · verify.tn.gov
Tankless Water Heater Installation
Converting from tank to tankless, including gas and venting.
Quick answer
We convert tank water heaters to tankless, including the gas and venting the change requires. We install across the whole service area, Chattanooga included. Tennessee license #5045.
Going tankless is not just a swap — it usually means new gas sizing and new venting, which is exactly why it has to be done properly. Done right it gives you endless hot water and floor space back. Done as a quick swap it underperforms, so we do the gas and venting properly or not at all.
Tankless is genuinely great for the right house and genuinely oversold for the wrong one. It heats water on demand instead of keeping a tank hot around the clock, so you get endless hot water and reclaim the floor space the old tank used. That is real, when the install is done right.
The catch is that the install is the whole game. A tankless unit pulls far more gas at once than a tank does, and it vents differently, so a proper conversion usually means new gas sizing and new venting. Skip that and you get an expensive unit that runs lukewarm under load. We would rather talk you out of it than install one that disappoints.
What the job covers
- Tank-to-tankless conversions, gas and venting included
- Gas line sizing to feed the higher demand a tankless unit needs
- Correct venting for the new unit
- Sizing to your peak flow rate, not a guess
- Guidance on hard-water protection so the unit lasts
How to tell
Signs you need tankless water heater installation
- You keep running out of hot water as the household has grown
- You want the floor space the old tank takes up
- Your tank is due for replacement anyway and you are weighing options
- High hot-water usage where on-demand heating pays off
- You are tired of paying to keep a tank hot when no one is using it
- Hard water keeps shortening the life of your tank heaters
Why tankless costs more to install than a tank
A tankless unit fires hard to heat water instantly, which means it needs a gas line sized to feed that demand and venting rated for it. On a lot of homes the existing gas line and flue were sized for a tank and are not enough. Upgrading them is most of the cost difference, and it is not optional if you want the unit to perform.
This is exactly why a quick swap that ignores the gas and venting is the classic way to end up unhappy with tankless. We do the full conversion or we tell you it is not worth it for your setup.
Hard water and keeping a tankless unit alive
Tankless units are more sensitive to hard water than tanks are, because scale builds up inside the heat exchanger, which is the expensive part. In the hard water common across southeast Tennessee, that matters.
That is why we talk through water treatment when it fits a tankless install. Our water quality work is how the scale problem gets handled properly, and it is the difference between a tankless unit that lasts and one that needs service far too soon.
How we work
How we handle tankless water heater installation
Check if it fits your house
Honest read on gas, venting, and hot-water habits before anyone commits to tankless.
Size to peak flow
Sized by how many fixtures run hot at once and the incoming water temperature, not house size.
Upgrade gas and venting
The larger gas line and correct venting the unit actually needs.
Install and commission
Set it, test it under load, and confirm it holds temperature, not just lights up.
Set up for longevity
Cover hard-water protection so the heat exchanger is not the first thing to go.
Permits
Some plumbing work requires a permit and an inspection, and some does not. Whether one is required for your job is determined by the Authority Having Jurisdiction — the city or county building and codes office for your address — and it is at their discretion.
Usually requires a permit
- Water heater replacement and tankless conversion
- Whole-house repiping
- Water service line and sewer line replacement
- Gas line installation and repair
- Relocating a fixture to a new position
Usually does not
- Drain cleaning and clearing blockages
- Emergency and repair work
- Like-for-like fixture replacement
- Water heater repair
- Camera inspection and diagnostics
This is general guidance rather than a ruling, and it can differ from one town to the next. The Authority Having Jurisdiction makes the determination. Across the Bradley–McMinn corridor we pull the permit and book the inspection ourselves. Inside Hamilton County and Chattanooga the permit office does not accept an application from our license class, so permit-required jobs there are referred to a licensed partner who does the work and meets the inspector.
Common questions
Tankless Water Heater Installation: your questions answered
Is a tankless water heater actually worth it?
Why does tankless cost more to install than a tank?
Can you install one in Chattanooga?
Will hard water hurt a tankless unit?
What size tankless unit do I need?
What kind of warranty do you offer?
Are you actually licensed?
Get service
Book Drain Pros TN for tankless water heater installation.
Call for the fastest response, request service online, or send the form and we’ll reach out. Woman-owned and family-run, licensed, with straight pricing you approve before we start and 24/7 emergency service.
TN Limited Licensed Plumber · #5045 · verify at verify.tn.gov
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