Hi Peggy I know you not big on “fresh water flush” due to the possibility of siphoning back into the fresh water holding tanks and in general heads aren’t designed to be hooked into pressured water, but necessity is the mother-of-invention. The water where I dock is simply horrible mainly because of the sewage treatment plant up the bay. Anyway, I think I’ve come up with something that would make most boaters smile, since they can make the unit themselves, can’t siphon back into the fresh water holding tanks and it nullifies the pressure of the fresh water system. I have had a unit on my sail boat for two years now serving 2 heads and have given the D-I-Y instructions to 3 other critical boaters who are quite happy with the unit, but before I let the world know how to do it I’d like your thoughts. Basically, it utilizes a small anti-spill reservoir tank. I simply tee’d off the boats pressure line through a shut-off valve, through an anti siphon valve, into the top of a small reservoir, thus eliminating the water pressure and chance of back flow. I mounted the reservoir higher that the head and put in a check vlave to eliminate any chance of water from the head flowing up hill into the reservoir and cut into the head supply line. The unpressurized water in the reservoir is moved only by the heads pump and a little help from gravity as you flush, while the water in the reservoir is replaced by your pressurized fresh water system. It’s that simple, doesn’t leak even in the worst of weather, and eliminates the problems associated with salt water. I did put a 2 way valve on the thru hull line just incase I needed to flush with salt water.
- Status
DON'T tell the world!
You have to be an engineer...'cuz only an engineer could have turned what should be a very simple project into a complex one..and still manage to leave your potable water supply at risk. 'Cuz a single check valve isn't enough to protect it from contamination from bacteria that can migrate into the flush water reservoir...you also need siphon breakers and redundancy in case of failure of the check valve or the siphon breaker. And a water valve or faucet (which IS a water valve) in the linethat remains closed except when opened to fill the reservoir. To install a flush water reservoir, all you had to do was tee the fill into a sink drain, with a y-valve in the drain line. To fill the tank, run water down the sink. Your reservoir could even have been an unvented bladder stuffed under the sink or anywhere else there's room for it...then you wouldn't have had to vent the reservoir. No check valves, anti-siphon devices, or water valves needed, just a garden hose y-valve--available from any hardware store for about $5. No possibility of cross contamination of the potable water...nor any need to figure out how to put the tank higher than the toilet--which, btw, is also NOT a good idea either...'cuz the only keeping the whole tankful when the wet/dry valve in the toilet fails, the whole tankful--without any shutoff valve, maybe even your whole water tank!--is gonna empty into the bowl and overflow it...not only making a major mess, but also exponentially increasing the risk of contaminating your potable water supply. So I would not recommend your solution to anyone else!
You have to be an engineer...'cuz only an engineer could have turned what should be a very simple project into a complex one..and still manage to leave your potable water supply at risk. 'Cuz a single check valve isn't enough to protect it from contamination from bacteria that can migrate into the flush water reservoir...you also need siphon breakers and redundancy in case of failure of the check valve or the siphon breaker. And a water valve or faucet (which IS a water valve) in the linethat remains closed except when opened to fill the reservoir. To install a flush water reservoir, all you had to do was tee the fill into a sink drain, with a y-valve in the drain line. To fill the tank, run water down the sink. Your reservoir could even have been an unvented bladder stuffed under the sink or anywhere else there's room for it...then you wouldn't have had to vent the reservoir. No check valves, anti-siphon devices, or water valves needed, just a garden hose y-valve--available from any hardware store for about $5. No possibility of cross contamination of the potable water...nor any need to figure out how to put the tank higher than the toilet--which, btw, is also NOT a good idea either...'cuz the only keeping the whole tankful when the wet/dry valve in the toilet fails, the whole tankful--without any shutoff valve, maybe even your whole water tank!--is gonna empty into the bowl and overflow it...not only making a major mess, but also exponentially increasing the risk of contaminating your potable water supply. So I would not recommend your solution to anyone else!
Fresh water from head sink
My Catalina 36 came with an arrangement that seems to work well. It is based on the sink drain using the same thru-haul as the head intake with the sink hose that Ts into the head intake just above the thru-haul. When the valve is open the sink drains to the water, when closed it drains to the head. At the end of the day just fill up the sink with fresh water and with the thru-haul closed it pumps directly into the head and allows fresh water rinses. Works great and allows us to keep fresh water in the head hoses over periods of non-use, hence reducing the odor from stagnet sea water.
My Catalina 36 came with an arrangement that seems to work well. It is based on the sink drain using the same thru-haul as the head intake with the sink hose that Ts into the head intake just above the thru-haul. When the valve is open the sink drains to the water, when closed it drains to the head. At the end of the day just fill up the sink with fresh water and with the thru-haul closed it pumps directly into the head and allows fresh water rinses. Works great and allows us to keep fresh water in the head hoses over periods of non-use, hence reducing the odor from stagnet sea water.
Point Taken
I like the idea of bladder and sink drain. I'm pulling the unit this weekend and going with your suggestion. Great advise. I guess, that's why your the "Head Mistres". Thank you.
I like the idea of bladder and sink drain. I'm pulling the unit this weekend and going with your suggestion. Great advise. I guess, that's why your the "Head Mistres". Thank you.
- Status