I installed an RO unit in my 2003 Newmar Dutch Star 40’ as one of the very first modifications. We have had an RO unit in our home for years and not knowing what the quality of water is at the various RV parks we’d be staying in, not to mention the potential for bacterial, viral and who knows what other contamination in the fresh water holding tank I considered the installation of an RO unit to be essential.
I installed a Watts “Zero Water Loss†system under the kitchen sink with a separate faucet for RO only. We have a “whole house†cartridge type filter for all incoming water and I didn’t feel it was necessary to use RO water for anything other than what we drink or cook with (i.e. not shower, sinks or toilet).
The Watts “Zero Water Loss†system incorporates a pump which, in a household situation is designed to pump the excess water that would normally go into the sewer, into the hot water line, thus eliminating the loss of approximately 5 gallons for every gallon of RO water produced by the RO system. At the time I thought that the pump would be necessary in order to pump the excess water back into the fresh water holding tank, but in retrospect I found that this is not necessary. A standard RO system will work just fine.
The first summer that we used this system I discovered that by having the excess water return to the fresh water holding tank we would have a problem with the fresh water tank overflowing when we were hooked up to the water supply in an RV park for an extended period of time. This could be remedied by periodically turning off the incoming water and using the water in the holding tank (which, of course required running the motorhome’s water pump). After the first summer I installed a valve under the sink and ran a second line to the sink drain pipe which allowed me to select either sending the excess water to the fresh water tank or to the gray water tank depending on whether we were in an RV park or dry camping. I also installed a switch to turn off the RO pump if, for whatever reason, I didn’t want to be producing RO water (such as if the fresh water tank were to run dry while dry camping). This switch, of course, would not be necessary with the standard RO system (i.e. one other than the Watts “Zero Water Loss†system).
We have been very happy with this system, as have our friends in whose coach I installed a similar system, and have felt much more confident about the quality of the water we are ingesting as we’ve traveled in 44 states and 9 provinces.
