Gas line sizing comes first
Oklahoma Natural Gas maintains the line that delivers gas to your house. Everything past that point, including the pipe that would feed a new tankless heater, belongs to the homeowner, and the gas company says customer piping should be inspected and repaired by a licensed contractor. Many Edmond homes from the 1970s through the 1990s were piped for a furnace, a range and a tank water heater. A gas tankless unit can draw far more gas than that old tank did, all at once, the moment a hot tap opens.
Venting is the other half of the plan. Condensing tankless units usually vent through plastic pipe to an outside wall and need a condensate drain, while non-condensing units need metal venting rated for them. We pick a route that keeps the vent clear of windows and keeps the condensate line out of the cold.
When the existing line is too small, the heater starves at high demand and throws errors or delivers lukewarm water. The fix is a properly sized new line from the meter or from a larger trunk. In Edmond, gas piping work falls under the city's mechanical permit, and the inspection list includes a gas line pressure test. We schedule that so the new piping is checked before the heater goes into service.
Tankless water heater flushing and descaling on Edmond water
Edmond's tap water is part Arcadia Lake and part groundwater pumped from the Garber-Wellington aquifer by the city's own well field, and the 2025 water quality report lists dissolved minerals in the supply. In a tank heater those minerals settle as loose sediment. In a tankless heater they cling as scale inside a narrow heat exchanger, where even a thin layer cuts flow, raises the temperature of the metal and triggers error codes.
Descaling means closing the service valves, circulating a descaling solution through the heat exchanger with a small pump, flushing it clean and clearing the inlet screen. If your unit was installed without isolation valves, we add them so future service takes far less time.
Is tankless a good fit for your Edmond home?
Tankless heaters suit larger Edmond homes with several bathrooms, where a family can run two showers and a dishwasher at once, and they free up closet or garage space. They do not shorten the wait for hot water at a far bathroom, though. If that is your complaint, a recirculation setup may matter more than the heater type.
| Question | Tank heater | Gas tankless heater |
| Hot water supply | Limited to the stored amount | Continuous, within its flow rating |
| Gas line demand | Modest | High at full fire, often needs a larger line |
| Mineral effect | Sediment in the tank bottom | Scale in the heat exchanger |
| Routine care | Annual flush | Periodic descaling and screen cleaning |
Signs your tankless heater needs service
- An error code on the display, or the unit shutting off mid-shower
- Water temperature that swings hot and cold
- Lower hot water flow than it had when new
- Unusual noise from the unit when it fires
- No hot water after a power outage or a hard freeze
Our main tankless water heater installation and repair page covers brands, sizing and conversions from tank heaters. For local water, utility and permit details, see our Edmond plumbing page.