ThermoMate CZ480NG Natural Gas Condensing Tankless Water Heater

What it delivers

The ThermoMate CZ480NG Natural Gas Condensing Tankless Water Heater is a condensing gas tankless with a 114,000 BTU/h burner and a stated maximum flow of 5.3 GPM.

Worked out from its input, it delivers roughly 4.8 GPM when the water only has to rise 45°F, and 3.1 GPM at a 70°F winter rise: 2 showers at 2 GPM in summer, 1 shower at 2 GPM in winter. Size it to your fixtures and climate.

At full fire it burns about 110 cubic feet of natural gas an hour. The gas line has to carry that on top of the furnace, range and dryer; a gas fitter sizes the pipe from its length and the total load.

Condensing means cooler exhaust in plastic vent pipe and a condensate line to a drain; most installs add a neutralizer cartridge on that line.

Other listed details: connections: 3/4" npt; material: Condensing; model: CZ480NG.

The listing gives dimensions of 13.77 in (W) x 21.65 in (H) and a weight of 26 lb.

Right unit for this house?

Install it when

One shower at a time in cold climates
Replacing a gas tank heater

Look at another unit when

More than 1 winter shower at once
Homes without a gas line

Strengths and trade-offs

Strengths

114,000 BTU/h input
Up to 5.3 GPM
Condensing efficiency

Trade-offs

Gas pipe sizing to confirm
Needs a condensate drain
Scale builds up without flushing

Install limits

Figures are the maker's or seller's own. Flow at a rise is our estimate from the input; gas, venting and electrical work needs a licensed professional.

Rated performance

Every figure below comes from the source shown in brackets. Where the maker doesn't state something, we say so instead of estimating.

Model number	CZ480NG	Retailer
Dimensions (seller)	13.77"W x 21.65"H	Retailer
Voltage	120 V AC	Retailer
Max flow (maker)	5.28 GPM	Retailer
Input (maker)	114,000 BTU/h	Retailer
Product weight	26 lb	Retailer
Material	Condensing	Retailer
Fuel	natural gas	Retailer
Condensing	non-condensing	Retailer
Connections	3/4" npt	Retailer

Rival units at this flow

Ranein RH12KG-C-NG 120,000 BTU Natural Gas Condensing Tankless Water Heater120,000 BTU/h, up to 5.1 GPM.

Rinnai RX130iN Condensing Tankless Water Heater130,000 BTU/h, up to 7.1 GPM.

Rheem RTGH-84DVLN-3 157,000 BTU Natural Gas Condensing Tankless Water Heater157,000 BTU/h, up to 8.4 GPM.

More gas tankless water heaters rated for similar demand

Full gas tankless water heaters spec grid · Every ThermoMate unit in the catalog

Final verdict

A sensible condensing gas tankless for one shower at a time in cold climates.

Buy this unit

Our links open this exact model's product page. Prices and stock change; check what's included before you order.

Prices change often; the button shows today's price.

Check price on Amazon

Each button opens this exact model. We may earn a commission on tracked links; it never changes what we publish. Disclosure

Questions buyers ask

Is the ThermoMate CZ480NG Natural Gas Condensing Tankless Water Heater big enough for two showers?

From its 114,000 BTU/h input we estimate about 4.8 GPM at a 45°F rise and 3.1 GPM at a 70°F rise, so 2 two-GPM showers with mild inlet water and 1 in a cold winter. The maker's flow chart for this model is the final word.

What size gas line does the ThermoMate CZ480NG Natural Gas Condensing Tankless Water Heater need?

At full fire it uses about 110 cubic feet of natural gas an hour. The pipe size depends on the length of the run and every other gas appliance on it; the maker's manual and a licensed gas fitter decide it.