Noritz Water Heater Recirculation — Loop, Pump & Setup

Recirculation on a Noritz works one of three ways. The EZTR series gives Noritz a competitive answer to Rinnai Sensei RX with a built-in pump; for NRC, EZ, and NCC units without a pump, external Grundfos or Taco pumps work. Three architectures, three configurations.

Why recirculate?

Without recirculation, hot water has to push the cold pipe water out before arriving at distant fixtures. In a large home, 30-90 seconds of cold water wasted per draw, plus the cold-sandwich effect on brief inter-draw pauses.

Option 1: EZTR with built-in pump

The simplest and cleanest. EZTR series units (EZTR40, EZTR50, EZTR75, EZTR111) include a recirculation pump in the cabinet. Connect a return line from the farthest fixture; the cabinet pump handles circulation. Scheduling via the controller (timer windows) or external on-demand button.

Required: dedicated return line from the farthest fixture back to the unit. In new construction this is trivial; in retrofits it costs $1,500-3,000 in plumbing.

Option 2: NRC/EZ/NCC + external pump + dedicated return line

Standard NRC, EZ, or NCC unit can recirculate with an external Grundfos UP15 or Taco 006 inline on a return line. Pump mounts on the return line near the unit. Scheduling via timer outlet or smart plug. Approximately $200-400 in pump parts plus install labor.

Option 3: External pump + crossover valve (retrofit-friendly)

If you don't have a return line, install a thermostatic crossover valve at the farthest fixture. The crossover routes hot-line water back through the cold line when loop temp drops below 95°F, creating a virtual loop on existing two-pipe plumbing. Pump still required at the heater. $300-500 in parts.

Tradeoff: the cold line carries warm water periodically; some homeowners find this annoying.

Control schemes

• Always-on: simplest, highest energy cost. Pump runs 24/7
• Schedule-based: set time windows (6-8 AM, 5-7 PM) via the controller. Best balance of efficiency and convenience
• On-demand button: wireless button at the farthest fixture. Pump runs for ~90 seconds on button press. Maximum efficiency
• Aquastat: pump runs when loop temperature drops below setpoint. Stops when loop is hot

EZTR control specifics

EZTR units schedule recirculation via the controller's menu:

• Up to 4 schedule windows per day
• Per-window minimum loop temperature setpoint
• Vacation/away mode pauses recirculation entirely
• On-demand button input — accepts a third-party wireless button

Noritz's EZTR scheduling is less sophisticated than Rinnai Circ-Logic learning mode. But for most installs, fixed schedules + occasional vacation mode is adequate.

Energy use ballpark

• Always-on: $20-45/month additional gas in typical 2,500 sq ft home
• Schedule-based (2 windows/day): $8-18/month
• On-demand button: $1-3/month when used

Recirculation and warranty

External pumps don't affect the Noritz warranty when properly installed (check valve in the return line, isolation valves, proper sizing). For EZTR built-in pump failures, the pump assembly is covered under the 5-year parts warranty.

Comparison to other brands

Bottom line

If recirculation matters, EZTR is the clean Noritz answer. If you've already bought an NRC, EZ, or NCC unit, add an external Grundfos with a timer — works fine, no major efficiency or convenience penalty. Always-on schedules waste gas; use schedule or on-demand control.