Is a tank less water heater a bad choice for a house with low water flow?
In short a tankless doesent require a high flow if anything a lower flow, the problem most folks have is a lower flow of hot water due to the fact the tankless heater can only heat the water so many degrees at a specific rate. For instance if your tap water is 50 degrees and you want a 110 degree water the unit has to be able to heat the water 60 degrees most units restrict the flow to maintain the temp with a max temp of ~130. The nice thing about tankless you never run out of hot water, when changing the water in our hot tub I set the heater at 110 and connect a hose to the hot water line and fill the entire tub hundreds of gallons and it is hot and ready to use when full. Where the problem comes in if you are showering and someone turns the hot on in the kitchen most tankless systems can't heat that much so the shower gets cold if using both hot and cold water, if the heater is set to the temp you want your shower and you are only using hot when another hot tap is turned on the flow drops but the temp stays fairly constant.