Plan for a cold-water feed, drain, nearby electrical outlet and enough cabinet space for cartridge replacement. Check smart-faucet hole requirements before buying.
Power is usually required
Most tankless RO systems use an electric booster pump to maintain membrane pressure and support higher production rates. Confirm outlet location before the unit arrives.
Cabinet dimensions matter
Measure width, depth and height with room to pull cartridges out. A system that technically fits may still be impossible to service in place.
Smart faucet considerations
Some models use a powered or data-connected faucet for TDS and filter-life indicators. That can make faucet-hole compatibility more important than with a basic RO faucet.
Drain and flushing
Tankless systems still create reject water and often run automatic flushing cycles. Install the drain connection exactly as specified and perform the initial flush before drinking.