Camco 35963 Water Heater By-Pass Kit, 10-Gallon

Winterizing gets a whole lot cheaper when you stop pumping antifreeze through your water heater. The Camco 35963 By-Pass Kit does exactly that. It reroutes the pink stuff around a 10-gallon tank so you fill the lines and skip the whole reservoir. On a 10-gallon setup that's roughly five gallons of antifreeze you don't buy every fall.

Here's the logic. A water heater is the single biggest holding tank in your fresh-water plumbing. Without a bypass, every drop of antifreeze you push through the system has to fill that tank before it ever reaches the faucets and the pump. That's slow, wasteful, and it leaves you flushing a diluted mess out of the heater come spring. Flip the three-way valve to bypass and the antifreeze takes the short route straight to the lines. The tank stays empty and dry all winter.

This is a permanent-install kit, so you plumb it in once and it lives on the boat or the rig. You get a three-way valve, a 12-inch hose, and the fittings to tie into the hot and cold ports on the heater. Set the valve to normal for the season and hot water flows through the tank like always. Set it to bypass before you lay up for winter and the tank is isolated. Two positions, no guesswork.

A few things worth knowing before you cut into your plumbing. The valve body needs room. Plan on three to four inches of clearance behind the heater to seat and turn it, which can be tight on some 10-gallon tank mounts tucked into a cabinet or a bilge locker. Dry-fit everything first. And check where your hot and cold outlets sit. The 12-inch hose covers a standard side-by-side port layout, but if your heater's outlets are offset or on opposite ends, you may need a longer run of hose to reach cleanly. Better to know that at the dock than halfway through the job.

Thread sealing matters here. Wrap Teflon tape on all the threaded connections, valve stem included, and you'll head off the slow weep that shows up after a couple of seasons on any three-way valve. Snug the fittings, don't gorilla them. The handle is plastic and it'll snap if you force a stuck valve, so if yours ever gets stiff, work it gently rather than cranking on it. On a high-vibration inboard install, some folks step up to a brass ball valve down the road, but the kit as shipped handles normal fresh-water duty just fine.

Mount it right and it lasts. Because this is a permanent installation, secure the valve body to a bulkhead or a solid surface instead of letting it hang on the hoses. Hanging weight puts stress on the fittings every time the boat pounds through a chop, and that stress is what starts leaks. A single screw or a clamp to hold the body steady is all it takes.

One habit to build: check the valve position twice a year. The most common mistake with any bypass kit isn't the install, it's leaving the valve in bypass mode after spring commissioning. Do that and you'll wonder why you've got no hot water all summer while the heater sits bone dry. Bypass in the fall, normal in the spring. Say it out loud each time and you won't get caught.

Who's this for? Anybody who lays up a boat or an RV with a 10-gallon water heater in freezing country. If you've been filling the whole tank with antifreeze every November, this kit pays for itself in a season or two of saved pink jugs, and it makes spring startup faster because there's no heater to drain and flush. The packaging is bilingual, English and French, so it's ready for the whole cruising range north of the border too.