hot water on Demand

chocophile · 05-11-2017, 11:35 AM

We have an on-demand Rennai heater in our year-round home. I am not too happy with it and would not buy another.

It is installed in our basement, which is about 50 degrees. The water sitting in the unit cools down quickly. When you turn the faucet on, you get 50 degree water for quite a while. It takes the unit a few seconds to decide to start up, then quite a while to produce real hot water. Even for faucets close to the heater, it takes a long time to get hot water. Once you turn it off, 5 minutes later it's back to cold water. We waste a lot of water waiting for it to get hot.

I asked the plumber if it could be adjusted somehow; he said no.

Given the high cost of an on-demand unit, I think a basic electric hot water heater could be better for a seasonal camp. You can get one for less than $350 and install it yourself, using fittings that do not require sweating pipe. Winterizing is very simple.

05-11-2017, 11:35 AM	#13
chocophile Senior Member Join Date: Apr 2004 Location: 19-Mile Bay Posts: 114 Thanks: 15 Thanked 31 Times in 14 Posts	Not Happy with On-Demand We have an on-demand Rennai heater in our year-round home. I am not too happy with it and would not buy another. It is installed in our basement, which is about 50 degrees. The water sitting in the unit cools down quickly. When you turn the faucet on, you get 50 degree water for quite a while. It takes the unit a few seconds to decide to start up, then quite a while to produce real hot water. Even for faucets close to the heater, it takes a long time to get hot water. Once you turn it off, 5 minutes later it's back to cold water. We waste a lot of water waiting for it to get hot. I asked the plumber if it could be adjusted somehow; he said no. Given the high cost of an on-demand unit, I think a basic electric hot water heater could be better for a seasonal camp. You can get one for less than $350 and install it yourself, using fittings that do not require sweating pipe. Winterizing is very simple.