Rheem RTGH-84DVLN-3 157,000 BTU Natural Gas Condensing Tankless Water

What it delivers

The Rheem RTGH-84DVLN-3 157,000 BTU Natural Gas Condensing Tankless Water Heater is a condensing gas tankless with a 157,000 BTU/h burner and a stated maximum flow of 8.4 GPM.

Worked out from its input, it delivers roughly 6.6 GPM when the water only has to rise 45°F, and 4.3 GPM at a 70°F winter rise: 3 showers at 2 GPM in summer, 2 showers at 2 GPM in winter. Size it to your fixtures and climate.

Gas load at full fire: about 152 cubic feet of natural gas an hour. An older half-inch line that already feeds a furnace often can't spare that, so have a gas fitter check the pipe size and run.

As a condensing unit it vents in the plastic pipe (PVC, CPVC or polypropylene) its manual lists and drains an acidic condensate, usually through a neutralizer.

The listing describes its venting as: direct vent.

Other listed details: material: Stainless Steel; model: RTGH-84DVLN-3; warranty: 1 Year Labor, 15 Year Heat Exchanger, 5 Year Parts.

The listing gives dimensions of 17.7 in (W) x 23.7 in (H), a weight of 59.9 lb and product only in the box.

Warranty, per the listing: 1 Year Labor, 15 Year Heat Exchanger, 5 Year Parts.

Right unit for this house?

Install it when

Houses running 2 showers at once in winter
Replacing a gas tank heater

Look at another unit when

More than 2 winter showers at once
Homes without a gas line

Strengths and trade-offs

Strengths

157,000 BTU/h input
Up to 8.4 GPM
Condensing efficiency

Trade-offs

Gas line may need upsizing
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	RTGH-84DVLN-3	Retailer
Dimensions (seller)	17.7"W x 23.7"H	Retailer
Features (seller)	Exclusive Hot Start Programming, Overheat Film Wrap, Electric Ignition	Retailer
Voltage	120 V	Retailer
Max flow (maker)	8.4 GPM	Retailer
Input (maker)	157,000 BTU/h	Retailer
Product weight	59.9 lb	Retailer
Material	Stainless Steel	Retailer
Warranty	1 Year Labor, 15 Year Heat Exchanger, 5 Year Parts	Retailer
Fuel	Natural Gas	Retailer
Venting	direct vent	Retailer
Condensing	Condensing	Retailer

Rival units at this flow

Rinnai RXP160iN Condensing Tankless Water Heater160,000 BTU/h, up to 9.0 GPM.

Rinnai RX180iN Condensing Tankless Water Heater180,000 BTU/h, up to 10.0 GPM.

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

More gas tankless water heaters rated for similar demand

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

Final verdict

A sensible condensing gas tankless for houses running 2 showers at once in winter.

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Questions buyers ask

How many showers can the Rheem RTGH-84DVLN-3 157,000 BTU Natural Gas Condensing Tankless Water Heater run at once?

From its 157,000 BTU/h input we estimate about 6.6 GPM at a 45°F rise and 4.3 GPM at a 70°F rise, so 3 two-GPM showers with mild inlet water and 2 in a cold winter. The maker's flow chart for this model is the final word.

What size gas line does the Rheem RTGH-84DVLN-3 157,000 BTU Natural Gas Condensing Tankless Water Heater need?

At full fire it uses about 152 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.