Years and years ago, before I dove deep into the mysteries of water heaters, this simple plumbing device kept odor at bay for my tenants, in the house where I myself now live. Connected to the bottom part of the tee is a plastic-lined steel nipple that went into the hot port of the water heater (which is still out there, by the way, well-maintained and now 36 years old). The plumbing to the house went out the side port. The way it worked was that when the smell returned, the tenants would shut off the cold-water valve, let a gallon out the drain valve, and then open the top valve (yellow handle here) and pour in hydrogen peroxide with a funnel. No more odor.
Simple, Cheap, But Not as Easy as an Anode
It’s really nice when I can recommend a simple solution to solve a problem. But a solution is a solution. A number of people have come seeking a solution to smelly water in cabins and vacation homes, and from what we’ve seen, even changing to a powered anode might not fix it if a water heater sat idle long enough.
For a long time, this page simply pointed to a possible alternative, that involves a bit more participation from the user, but which works. It makes more sense to leave be whatever anode is already in the tank, and to just rig a plumbing assembly, like the one above, onto the water heater in the hot port, and pour a couple of pints of drugstore hydrogen peroxide into the tank when you arrive for a visit.
Soon the smell will vanish. You can use and drink the water immediately. The peroxide is already a low concentration and it’s then diluted in gallons of hot water. That will solve the problem until you go home. You’ll have to do the same thing on each visit.
People occasionally ask, “why not the cold port?” It’s because the dip tube is in the cold port and being only 3/4-inch-diameter, it means you’ll have to drain a whole lot more water out of the tank or wait a really long time for the water level in and out of the tube to equalize as you pour in the peroxide.
People kept asking if I sold these parts. I decided maybe it was time I offered them. They are not always available locally, especially PEX-lined steel nipples.
— Randy Schuyler
Peroxide Fix Plumbing Assembly, consisting of lead-free brass tee, ball valve and nipples, 4-inch plastic-lined steel nipple, pipe-thread seal tape and instructions; requires about 15 inches of overhead clearance: