Prices for on-demand systems vary depending on the size of the pump and the type and number of controllers, but we typically charge between $750 and $1,250 per installation. Prices for the least-expensive hard-wired undersink kits start at about $400 and range up to about $900; plumbing a dedicated return leg or wiring a new outlet can add significantly to the installed cost. In homes where hot-water supply pipes travel in more than one direction — for instance, to two separate wings of the house — more than one pump may be required.
Payback. On-demand systems will always cut down on wasted water, but payback depends on such factors as the owners’ usage habits; the size and design of the piping; annual runtime of the pump and local utility rates; and local water and sewage fees, which can be high in areas subject to water shortages. In our area it may take a few years, but these systems do pay for themselves.
Leigh Marymor is a plumbing contractor in Emeryville, Calif.