What it delivers
The APUS AP-ADSK-180G13 18 kW Electric Tankless Water Heater is a whole-house electric tankless rated at 18 kW on 240 volts. Its listing gives a maximum flow of 4.4 GPM.
Worked out from its input, it delivers roughly 2.7 GPM when the water only has to rise 45°F, and 1.8 GPM at a 70°F winter rise: 1 shower at 2 GPM in summer, less than one 2 GPM shower in winter. Try your own inlet temperature.
At 240 volts 18 kW is about 75 amps. The maker calls for 3 × 40A double-pole breakers. Whether your panel can carry it alongside heating and cooking loads is an electrician's call.
No flue, no gas line and a compact box on the wall; the trade-off is that a cold winter inlet cuts its flow sharply.
Other listed details: connections: 3/4" npt; material: Sheet Metal with Insulating Paint; model: AP-ADSK-180G13; warranty: 2 Year Manufacturer Warranty.
The listing gives dimensions of 11.42 in (W) x 17.72 in (H).
Warranty, per the listing: 2 Year Manufacturer Warranty.
Right unit for this house?
Install it when
- One shower at a time in mild climates
- Homes with no gas service
Look at another unit when
- Panels without spare capacity
- More than 1 shower at once in cold winters
Strengths and trade-offs
Strengths
- 18 kW
- Up to 4.4 GPM
- No venting or gas line
- Breakers stated by the maker
Trade-offs
- Draws about 75 A
- Flow drops with cold inlet water
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 | AP-ADSK-180G13 | Retailer |
|---|---|---|
| Dimensions (seller) | 11.42"W x 17.72"H | Retailer |
| Power | 18 kW | Retailer |
| Voltage | 240 V | Retailer |
| Max flow (maker) | 4.4 GPM | Retailer |
| Warranty | 2 Year Manufacturer Warranty | Retailer |
| Material | Sheet Metal with Insulating Paint | Retailer |
| Breakers (maker) | 3 × 40A double-pole breakers | Retailer |
| Connections | 3/4" npt | Retailer |
Rival units at this flow
More electric tankless water heaters rated for similar demand
- SIVUATEK V7B-180B 18 kW Electric Tankless Water Heater
- Eemax HA027240 18 kW Electric Tankless Water Heater
- Ranein RE18K 18 kW Electric Tankless Water Heater
- WINTEMP YQ-WN18K 18 kW Electric Tankless Water Heater
Full electric tankless water heaters spec grid · Every APUS unit in the catalog
Final verdict
A sensible whole-house electric tankless for one shower at a time in mild climates.
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