What it delivers
The ThermoMate CZ422NG Natural Gas Tankless Water Heater is a non-condensing gas tankless with a 113,000 BTU/h burner and a stated maximum flow of 5.0 GPM. Its listing gives a UEF of 0.81.
Flow depends on how cold the incoming water is. Our estimate from its input: 3.9 GPM at a 45°F rise, falling to 2.5 GPM at 70°F, which is 1 shower at 2 GPM on a cold-climate winter day. Check it against your own fixtures.
At full fire it burns about 109 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.
Non-condensing indoor units run hot exhaust and vent in the maker's listed vent system (often stainless Category III), which costs more than plastic.
Also on the listing: connections: 3/4" npt; material: 5 GPM; model: CZ422NG.
The listing gives dimensions of 13.77 in (W) x 21.65 in (H) and a weight of 22 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
- 113,000 BTU/h input
- Up to 5.0 GPM
- UEF 0.81
Trade-offs
- Gas line may need upsizing
- Stainless venting costs more
- Needs periodic descaling
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 | CZ422NG | Retailer |
|---|---|---|
| Dimensions (seller) | 13.77"W x 21.65"H | Retailer |
| Voltage | 120 V AC | Retailer |
| Max flow (maker) | 5 GPM | Retailer |
| Input (maker) | 113,000 BTU/h | Retailer |
| Product weight | 22 lb | Retailer |
| Material | 5 GPM | Retailer |
| UEF (maker) | 0.81 | Retailer |
| Fuel | natural gas | Retailer |
| Connections | 3/4" npt | Retailer |
Rival units at this flow
More gas tankless water heaters rated for similar demand
- GASLAND CE528NG 150,000 BTU Natural Gas Tankless Water Heater
- Camplux CA528 150,000 BTU Natural Gas Tankless Water Heater
- Camplux CA528M-NG 150,000 BTU Natural Gas Tankless Water Heater
- Camplux CA528WNG 150,000 BTU Natural Gas Tankless Water Heater
Full gas tankless water heaters spec grid · Every ThermoMate unit in the catalog
Final verdict
A practical non-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.
Each button opens this exact model. We may earn a commission on tracked links; it never changes what we publish. Disclosure