tankless H2O heater + H2O efficient dishwasher = problems
Just figured out that my water efficient Kenmore dishwasher (not top of the line) doesn't draw enough water to keep my Rennai tankless water heater (propane) fired up. Dishwasher has a heating element but manual says to supply water at 120 degrees so apparently the dishwasher's internal heating element can't heat cooler water enough to get the dishes clean.
What is my best AFFORDABLE fix? At this point, anything more than about $250 to fix this means I'm just gonna have to wgo back to washing my dishes by hand and the money spent on the dishwasher was wasted dollars.
I've heard of water recirculating systems but don't know how expensive they are or how difficult to install. Plus, I don't really understand quite how they work. If they basically keep your tankless in "on" mode all the time, seems like that totally defeats any energy savings potential.
On the internet I've also seen some very small electric tankless heaters for under the sink that one can apparently just plug into the wall. But I can't find any info regarding minimum flow rate to keep even those fired up. And, in listening to my dishwasher run, it sounds like it spritzes water in VERY short cycles. So, I'm not sure that even those would work to keep hot water flowing to a dishwasher. Any one know for sure?
Is my best option to get a small water heater tank for under the sink? If so, can anyone suggest a particular model/size? Is there one that will heat a tank of water in, say, an hour or two so I could turn it on while fixing dinner and know that the water would be hot by the time the dishwasher was loaded? Even better would be one that I could put on a timer to cut back off once the dishwasher cycle was done.
Seems like the tankless water heater manufacturers and the water efficient dishwasher (and clothes washer) manufacturers would get together and figure out how to make these "green" products work WITH each other!