Hot Water List
Menu

RELIANCE WATER HEATERS TK-510CX3 1**

RELIANCE WATER HEATERS TK-510CX3 1** is in the DOE listing as of Oct 19, 2026.

  • Gas tankless water heater
  • 1 listed model

Not listed as ENERGY STAR certified on Oct 19, 2026.

Its figures are also listed under A. O. Smith TK-510CX3 1**.

Flow at a 67°F rise
5.0gallons per minuteCertified
Advertised flow
4.7gallons per minuteRELIANCE WATER HEATERS, at a 67°F rise
UEF
0.81Uniform energy factor
See it among every gas tankless model

Flow where you live

Colder incoming water needs a bigger rise, so the heater gives less flow.

Cold water
Cold water must be at least 10°F colder than the hot water setting.
Flow estimate
The estimate uses the lowest certified flow among the listed models. It is about 4.8 gal/min at a 70°F rise.

Flow limits

  • The estimate excludes the flow needed to turn the heater on, heat lost in pipes, and installation.
  • Cold water from a well or long pipe run can differ from the temperature you enter.
  • Without a stated flow limit, estimates for warmer water may exceed the heater’s actual flow.

Advertised and certified figures

RELIANCE WATER HEATERS TK-510CX3 1**: advertised and certified
RELIANCE WATER HEATERS TK-510CX3 1**: advertised and certified UEF: advertised 0.81, certified 0.81. Flow: advertised 4.7 gal/min, certified 5.0 gal/min (advertised at a 67°F rise, certified at a 67°F rise). UEF Advertised 0.81 Certified 0.81 Flow · advertised at a 67°F rise, certified at a 67°F rise Advertised 4.7 gal/min Certified 5.0 gal/min
FigureAdvertisedCertifiedAdvertiserRead
UEF 0.81 0.81 RELIANCE WATER HEATERS Read Oct 5, 2026
Flow 4.7 gal/min at a 67°F rise 5.0 gal/min at a 67°F rise RELIANCE WATER HEATERS Read Oct 5, 2026

See how advertised flow compares across tankless models

Certified figures by listed model

Model numberUEFFlow at a 67°F rise (gal/min)Recovery efficiencyDraw pattern
TS-510CX3 1**0.815.083%High

UEF is the uniform energy factor. A dash means the model has no such figure.

At a 67°F rise, its flow in the test is 5.0 gallons per minute. The gas tankless type has a median flow of 4.8 gallons per minute. Its flow at a 67°F rise trails 176 of the 487 gas tankless models.

On Oct 19, 2026, this heater was not listed as ENERGY STAR certified. In tests, 81% of the energy it uses ends up as hot water (UEF 0.81). In the test, daily hot water use was set to high (its draw pattern). Among 399 gas tankless models on its draw pattern, 327 have a higher UEF. For its type and draw pattern, the UEF runs from 0.81 to 0.98. Of the energy it spends heating water, 83% ends up in it (its recovery efficiency).

There are 5 more basic models with the same test figures. Each of them is listed under a different brand. For the full group, see the A. O. Smith TK-510CX3 1**.

Also listed as

They carry every figure in the table above.

Updated Oct 19, 2026 · Methodology

Not covered

  • Changes to an advertised figure after the date beside it.