Does the Noritz NRC66DVLP Tankless Water Heater provide enough hot water for a large household?

The Noritz NRC66DVLP can provide enough hot water for a large household provided the simultaneous demand does not exceed its 6.6 GPM flow rate capacity. Because this is a tankless water heater—a unit that heats water instantly as it flows through the device rather than storing it in a tank—the 6.6 GPM rating is the definitive limit for your home’s concurrent usage.

The Noritz NRC66DVLP delivers a 6.6 GPM flow rate, which is sufficient for running two standard showers simultaneously or one shower and a sink at the same time. We selected this unit for our comparison because it offers high-efficiency condensing technology with a low NOx output. Since tankless units rely on a continuous heat exchange, the 6.6 GPM limit is the primary bottleneck for large households; if a third shower is opened, the temperature will likely drop. This unit features a remote thermostat and a 6′ power cord, but because it is a condensing model, it requires specific venting with Schedule 40 PVC pipe and fittings to handle the acidic moisture produced during operation. You must verify the specific gas line sizing and electrical requirements through the manufacturer’s support page to ensure your home’s infrastructure can support the unit’s peak output.

What to Check Before Buying the Noritz NRC66DVLP

Because tankless water heaters provide a continuous stream of hot water, verifying your home’s specific plumbing and infrastructure limits is essential to ensure the unit performs as rated during peak demand.

• Confirm your household’s peak demand does not exceed the 6.6 GPM maximum flow rate.
• Verify that your plumbing can maintain the minimum and maximum incoming water pressure required for full capacity.
• Ensure your venting configuration meets the requirements for a condensing exhaust using Schedule 40 PVC.
• Check the manufacturer’s compatibility page for the specific gas line sizing and high-amperage electrical circuit requirements.
• Verify the requirement for a specific condensate drain line or neutralizer to handle acidic moisture from the condensing process.

Comparing the Noritz NRC66DVLP to Other Tankless Options

The Noritz NRC66DVLP sits in the high-efficiency condensing category, which is ideal for users prioritizing energy savings and low emissions. Buyers with extremely high-volume needs, such as those requiring three or more simultaneous showers, may need to look at higher-output commercial-grade units or multi-unit systems that exceed 6.6 GPM. If your home has low incoming water pressure, you might also consider models specifically designed to operate efficiently at lower pressures to avoid a flow rate shortfall.

You should choose the Noritz NRC66DVLP if you need a high-efficiency, low-emission water heater that can comfortably handle two simultaneous showers or a combination of a shower and a sink.

If you need a unit for exterior placement, explore our comparison of the best outdoor tankless hot water heater options.