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Switching from a tank to a tankless water heater is rarely a straight swap. The unit itself is the small part. Most Triad conversions also need a larger gas line, a new stainless vent, a condensate drain and an electrical circuit. Budget for all four or the quote you accepted will change on install day. Our tankless water heater service covers the whole conversion.
Key Takeaways
- The unit is maybe half the job. Gas line, venting, condensate and power make up the rest.
- A 40,000 BTU tank line will not feed a 199,000 BTU tankless unit. Gas sizing is the number one surprise.
- Tankless cannot reuse a tank flue. Condensing units need sealed stainless or PVC venting.
- Triad groundwater is cold in winter, which cuts the flow rate a unit can deliver.
- Already decided? Our tankless water heater vs tank guide handles the choice itself.
What Actually Changes When You Convert
A tank water heater burns gas slowly and stores the result. A tankless unit burns a great deal of gas for a short time and stores nothing. That single difference drives every other change in the install.
A typical 50 gallon gas tank runs around 40,000 BTU. A whole-house condensing tankless unit runs 150,000 to 199,000 BTU. That is roughly four times the fuel demand through the same pipe that was sized decades ago for the tank.
According to the Department of Energy, water heating energy use accounts for about 18% of a home’s total energy use and is usually the second largest energy expense in the house. That is the prize. Getting there properly is the work.
The Four Things That Usually Need Upgrading
- Gas supply. Most conversions need the line stepped up, sometimes all the way back to the meter. Occasionally the meter itself is undersized.
- Venting. A tank vents into a metal flue. A condensing tankless unit needs its own sealed stainless or PVC vent run, terminated to code.
- Condensate drain. Condensing units produce acidic water that has to be neutralised and drained, which means a drain within reach.
- Electrical. Even a gas tankless unit needs power for its controls and fan. Older closets often have no outlet at all.
None of these are optional and none of them show up in an online unit price. When a quote looks far below everyone else’s, one of these four is missing from it.
Where Tankless Units Go in Triad Homes
Location decides how much pipe and vent has to be run, and it is worth thinking about before the installer arrives.
Older High Point and Winston-Salem homes often have the tank in a hall closet or a crawlspace. A closet install means a vent run through the roof or an exterior wall, and a condensate drain that may not exist nearby.
Newer subdivisions in Oak Ridge, Summerfield and Kernersville usually have the tank in the garage, which is the easiest conversion. Exterior wall venting is short, a floor drain or laundry line is often close, and power is already there.
Some homeowners put the unit outside on an exterior wall. That works in our climate most years, but it needs freeze protection and a nearby circuit, because the unit relies on power to keep itself from freezing.
Sizing: Why Winter Groundwater Matters Here
A tankless unit is rated by how much it can raise the water temperature at a given flow rate. That rating collapses when the incoming water is cold.
In the Piedmont, incoming water sits comfortably warm in August and gets genuinely cold in January. A unit that delivers plenty of hot water in summer can run out in winter if it was sized on the wrong assumption.
| Household | Simultaneous Demand | Rough Flow Needed | Winter Note |
|---|---|---|---|
| 1 to 2 people, 1 bath | One shower | 2.0 to 2.5 GPM | Most units cope |
| 3 to 4 people, 2 baths | Shower plus sink | 4 to 5 GPM | Size for winter, not summer |
| 5 plus people, 3 baths | Two showers plus laundry | 7 to 9 GPM | Often needs two units |
| Large home with tub filler | Tub plus shower | 9 GPM plus | Consider a recirculation loop |
Undersizing is the reason people end up disliking tankless. The unit is not faulty. It was picked for a smaller house than the one it was fitted in.
What the Conversion Costs and What Drives It
We do not publish a flat price, because the same unit in two houses on the same street can differ by a wide margin depending on the four upgrades above. What we do is quote the whole job before anything starts, and if you decline the quote there is no charge.
The cost drivers, in rough order of impact:
- How far the gas line has to be reworked and whether it runs through finished space.
- Vent path length and termination. Through a garage wall is simple. Up through two floors and a roof is not.
- Condensate handling, including whether a neutraliser and a pump are needed.
- Electrical work to get a circuit to the unit.
- Whether a water softener is needed first, because scale is what kills tankless units early.
Because it is a larger project, we offer Wisetack financing from $500 to $25,000 over 3 to 60 months with a soft credit check, and 0% APR on selected projects. Details are on our plumbing financing options page.
Hard Water Will Decide How Long It Lasts
A tank hides scale on its floor for years. A tankless unit runs water through a narrow heat exchanger, so the same minerals coat the one surface that has to transfer heat.
Scale shows up as reduced flow, fluctuating temperature and eventually an error code. Annual descaling keeps it away, and on genuinely hard water a softener ahead of the unit pays for itself in heat exchanger life.
If your home runs on a private well in Stokesdale, Wallburg or Advance, treat this as a requirement rather than an upsell. A hard water test before the conversion tells you which category you are in.
Tank to Tankless Questions Homeowners Ask
Can you put a tankless water heater where the tank was?
Usually yes, and it frees up floor space because the unit hangs on the wall. What rarely transfers is the existing vent and gas line. Both are sized for a tank and both normally need replacing during the conversion.
Do I need a bigger gas line for a tankless water heater?
Most of the time, yes. A tank runs near 40,000 BTU while a whole-house tankless unit runs 150,000 to 199,000 BTU. The existing line and sometimes the meter have to be checked against that load before anything is ordered.
Does a tankless water heater need electricity?
Yes, even gas models. The controls, ignition and fan all need power, which means no hot water during an outage unless the unit is on a generator circuit. A gas tank with a standing pilot keeps working in an outage, and that is a genuine trade-off.
How long does a tank to tankless conversion take?
A straightforward garage conversion is typically a single day. Add a long vent run, a gas line through finished walls or new electrical, and it becomes two days. Permit and inspection scheduling can add time beyond the work itself.
Is switching to tankless worth it if my tank still works?
If the tank is under eight years old and healthy, the honest answer is usually no, not yet. The conversion cost is the same whether you do it now or in four years, and you would be throwing away good remaining life. Plan it as the replacement, not as an upgrade for its own sake.
Get the Conversion Scoped Before You Buy a Unit
The mistake we see most often is a homeowner buying a tankless unit online and then discovering the gas line, the vent and the power are not there. The unit sits in a garage for months.
Call All Star Plumbing at (336) 462-1080 and we will look at your gas supply, vent path, drain and power first, then quote the whole conversion as one number. A real person answers 24 hours a day, and if we cannot fix it you do not pay. You can also book a tankless consultation online.
If your current tank has simply failed and you need hot water back today, our water heater repair and replacement team can fit a like-for-like tank now and plan the conversion later. Efficiency ratings for both types are listed on the ENERGY STAR water heaters pages.
Family owned in High Point since 2007, licensed, bonded and insured, and certified on Navien, Rinnai, AO Smith, Rheem, Bradford White and State.
All Star Plumbing
4003 North Main Street
High Point, NC 27265
Phone: (336) 462-1080
Hours: Open 24 hours, 7 days a week
NC Plumbing License #15130
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