Noritz NRCB199-DV-NG Combi Boiler Tankless Water Heater

The Noritz NRCB199-DV-NG Combi Boiler Tankless Water Heater is Noritz's combi boiler — combined space-heating and tankless DHW in a single wall-mounted unit. 199,900 BTU heating + 11.1 GPM DHW, 95% AFUE, 0.93 UEF on DHW side, 10-year warranty. Direct competitor to Navien NCB-240E for homes upgrading both boiler and water heater.

Headline specifications

• Type: condensing combi boiler with integrated tankless DHW, natural gas (LP-convertible)
• Space heat output: 199,900 BTU/h (heating side)
• DHW max flow: 11.1 GPM at 35°F rise
• AFUE heating efficiency: 95%
• DHW UEF: 0.93
• Warranty: 10-year heat exchanger, 5-year parts
• Venting: PVC/CPVC/polypropylene up to 100 ft
• Dimensions: 33" H × 17" W × 14" D
• Wall-mounted

Who this model is for

Homes with hydronic space heating + simultaneous boiler-and-water-heater replacement. The NRCB199's higher 199,900 BTU heat output (vs 80,000 on the Navien NCB-240E entry tier) makes it the right pick for larger homes — 2,500+ sq ft houses, multi-zone hydronic, radiant-floor systems, or older homes with cast-iron radiator distribution requiring higher water-loop temperatures.

Wrong product for forced-air-heated homes (use standalone tankless instead). Wrong product if your boiler is undersized for the house — combi DHW priority will exacerbate cold rooms during shower demand. Right-size your heating load before committing to combi.

Where the NRCB199 beats the alternatives

Vs Navien NCB-240E ($2,949): NRCB199 has higher 199,900 BTU heat output (vs Navien NCB-240E's 80K BTU for the entry tier — Navien's higher-tier NCB-H goes to 199K). For large homes with high heat-load demand, NRCB199 sizing is correct. For smaller homes, Navien NCB-240E is correct sizing.

Vs separate boiler + indirect tank: NRCB199 replaces two appliances with one. Saves $1,500–$3,000 in install cost (fewer connections, single vent, single gas drop) and ~25% on annual gas use via 95% AFUE.

Vs standalone tankless + retain old boiler: if your boiler is also at end of life or below 80% AFUE, combi solves both problems. If boiler is healthy, standalone tankless is the right pick.

Where it falls short

10-year warranty is shorter than the standalone NRC1111 tankless 12-year. Combi boilers operate higher duty cycle.

DHW priority means space heating briefly drops during long simultaneous showers. With 199K BTU on the heat side, this is less severe than smaller combis, but still real.

Installer expertise — combi boilers are not standalone tankless. Verify Noritz combi-certified installer, not just NRC tankless certification.

0.93 UEF on DHW side is lower than 0.96 on the standalone NRC1111. Combi DHW heat exchanger is shared with heating loop, which reduces standalone efficiency slightly.

Wall-mount install requires structural anchor for ~95 lb unit.

Cold-water sandwich on DHW side — no buffer tank.

Install considerations

3/4" gas line required. PVC/CPVC/polypropylene venting up to 100 ft. 120V outlet. Connections for both DHW (hot and cold) and hydronic (supply and return) loops. Boiler-certified installer required. Permit required.

Install cost: $5,000–$9,500 for typical boiler+tank-to-combi conversion. New construction: $4,000–$6,500.

Maintenance

• Annual descaling (DHW side)
• Annual hydronic system check
• Burner inspection every 2 years by combi-certified technician
• Hydronic loop flush every 5 years

Bottom line

The Noritz NRCB199 is the high-capacity combi boiler with integrated tankless DHW — 199,900 BTU heating + 11.1 GPM DHW. Right pick for larger hydronic-heated homes (2,500+ sq ft) upgrading both boiler and water heater. For smaller homes, the Navien NCB-240E at lower BTU heating is correct sizing. For forced-air homes, use standalone tankless (NRC1111) instead.