Marey ECO90 8 kW Electric Tankless Water Heater

The Marey ECO90 is an 8 kW whole-house electric tankless water heater, smaller than the ECO110 and sized specifically for single-bathroom homes in mild climates. The smallest unit in Marey's whole-house electric line.

Specs: 8 kW, single 40-amp double-pole breaker, 33A continuous draw at 240V. Capacity: 1.0 GPM at a 60°F rise or 1.5 GPM at a 40°F rise. Copper heat exchanger.

The 8 kW class is at the boundary between point-of-use and whole-house — adequate for a single low-demand bathroom in warm climates, inadequate for any cold-climate primary residence use. The single 40A breaker fits virtually any 100A panel without load-calc concerns.

Marey's value positioning: about $200 unit versus $230-$320 for similar-capacity competitors. The build trade-offs reflect the lower price point: copper (vs stainless) heat exchanger requires more frequent descaling in hard water, shorter warranty (10-year heat exchanger vs lifetime for EcoSmart), 1-year electronics warranty.

Right buyer: single-bathroom warm-climate home with 1-person occupancy, RV with 50A shore power, off-grid solar setup where 8 kW capacity matches available production. About $500-$800 installed depending on electrical run.

Wrong buyer: cold-climate homes (winter capacity 1.0 GPM is genuinely inadequate), multi-bath homes, or any primary residence where reliable shower performance matters.