Camco 10473 3/4" T&P Water Heater Relief Valve

The Camco 10473 is a temperature and pressure relief valve, the safety valve that sits on your water heater and keeps a bad day from turning into a dangerous one. Every tank-style water heater needs one. When the water inside gets too hot or the pressure climbs too high, this valve opens and vents before anything ruptures. It's a small brass part doing one of the most important jobs on your rig or your boat.

This one is factory set to open at 150 PSI and 210 degrees Fahrenheit. Those aren't numbers you adjust. They're built in at the factory and CSA certified to ANSI Z21.22, the standard that covers relief valves on water heating equipment. So when you thread this in, you know it's going to relieve at the right point every time. No guessing, no calibration, no fiddling.

The connection is a 3/4 inch NPT thread, the common size on RV and marine water heaters. The probe reaches 4 inches into the tank so it's actually sensing the water temperature, not just the air near the fitting. The shank measures 1 3/16 inches. If your old valve is a 3/4 inch NPT unit, this one drops right into the same port.

What makes it last is the build. The body is brass, the pressure spring is stainless steel, and the probe is epoxy-coated to fight corrosion. And here's the part that matters on an RV or a boat: there are no gaskets. Gaskets are the thing that dries out, cracks, and starts weeping after a few seasons of heat cycles. Take them out of the equation and you've got a valve that seals on metal and holds up. The epoxy coating on the probe keeps mineral and corrosion buildup off the sensing element, which is usually what makes an old valve either stick shut or drip constantly.

So when do you replace one? A few signs. If your relief valve is weeping or dripping water even when the heater is behaving normally, the seat is worn and it's time. If it's crusted with corrosion or mineral scale, replace it. If you've had a freeze event, or the valve is a few years old and you're doing a spring recommission, swapping the T&P valve is cheap insurance. And if the valve ever lets go and dumps hot water, don't just reset it and hope. Figure out why it opened, then put a fresh valve in.

Installation is straightforward for anyone comfortable with a wrench. Kill the power or gas to the heater, let it cool, shut the water supply, and relieve the tank pressure. Back out the old valve, clean the threads, wrap fresh thread sealant, and thread the 10473 in snug. Point the discharge so it drains somewhere safe, not at a wall or a wiring run. Then fill, pressurize, and check for drips. That's it. Most folks have it done in under twenty minutes.

A couple of honest notes. This is a replacement safety valve, not a tuning part, so don't expect to change the set point. It ships as the valve itself in English and French carded packaging. If your water heater uses a different thread size or a longer probe, check your existing valve before ordering so you match the port. And never plug or cap a relief valve to stop a drip. If it's dripping, replace it. That valve is the last line of defense on a pressurized tank of hot water.

For RV owners winterizing and de-winterizing every year, or boaters keeping a cabin water heater in good order, the 10473 is one of those parts worth keeping on the shelf. It's inexpensive, it's a known-good CSA certified valve, and it protects a system that runs hot and under pressure every time you use it. When yours starts to weep, you'll be glad you've got a fresh one ready to go.