Repairing — Not ‘Replacing’ — the Ripoff Watts Comfort/Sensor Valve

Here’s the same content in a video: https://youtu.be/7_wKKjn8oKc

About the circulator: This procedure pertains to the Watts Hot Water Circulator (Amazon) that provides faster hot water at faucets than waiting for it to make the whole trip from the hot water heater. This otherwise wonderful gadget uses one or more proprietary devices at the most distant faucets, to occasionally shunt the hot water through the cold water line, to do its magic.

About the valves: The proprietary device is called a comfort valve. It’s so-named because it is replaced every few years at great profit to the manufacturers, causing them immense comfort. It routinely sells for about $50. Imagine having a few hundred thousand of these things out in the wild, and people buying new valves like clockwork. Think of the beach house that must get ya.

I have two such valves in my house. The first two lasted about 4 or 6 years, not sure. Now they both failed again, about 6 years later. Honestly, the $50 is not a big deal if they routinely last 6 years, but I just bought two new ones and neither passed the simple self-test. (The test: when you turn the cold water shut-off valve at the faucet off, and then open the cold water spigot, water should flow [from the hot side!] until it becomes hot… then trickle down to no flow at all.)

So I got to wondering about about actually fixing the %$#*&#! device. It must have some piece that expands when heated, which in turn blocks the shunt (doctors call it a fistula) between the hot and cold side. There’s a little push pin that keeps the guts of the device from popping out. I removed this pin and started experimenting.

Inside is a little piston and cylinder affair with springs on both ends. The piston has a rubber boot around it and the cylinder. You can pull the boot back and actually remove the piston. Putting it in hot water, I was pretty sure I measured it expanding about 5 millimeter, but when I chilled it, it didn’t retract. Aha… it requires the springs to contract… and it might have been slightly seized up, not sure. At first I thought it used a metal or other substance that expanded when heated; then I wondered if it used only air… requiring a really tight fit which could explain degradation over time; but the more I experimented, it seems like there is a substance inside the cylinder that expands. Upon cooling, it seemed that it required pressure to get it to contract gradually, thus I don’t think it’s simply air doing the magic.

There’s a screen at the hot side that was 90% dirty on mine. Either that or oiling the piston must have been what fixed my valve, no way of knowing.

Steps in Brief

1. Take it apart.
2. Clean the screen.
3. Put a drop of oil on the cylinder.
4. Using a special tool that you have to make to hold the parts in while you reinsert the pin, put it together.

Detailed Steps

More images below, to keep the steps uncluttered.

1. The entire guts will spring out when you do this step, so keep your hand over everthing! Use a needle-nose pliers to reach inside the hot side of the chamber to successively lever the drift pin (?) out.
2. Remove the parts.
3. Clean the screen.
4. Try to pull/push the piston in the cylinder. Does it move freely? Put a drop of oil on it.
5. Make a custom tool: From a dowel or plastic rod approximately 1/2" diameter, make a tool to reassemble the part. You’ll need to cut a notch in one end of the dowel, to enable the drift pin to pass in front of the screen.
6. Stand the valve upright with the hot side up.
7. Put the parts in the barrel: small spring, piston, cylinder, large spring, screen.
8. Grip but do not squeeze yet, with a wide pliers like a channel lock on the drift pin and opposite side of the barrel.
9. The entire guts MIGHT spring out when you do this step, if you aren’t lucky on your first try. With your custom tool, push down on the screen (and the springs), lining up the slot to allow the drift pin to fit into it.
10. Squeeze the pliers until the pliers’ jaw bottoms out on the plastic.
11. Look inside and make sure the screen is behind the pin, so far.
12. Put the custom tool back in, turning it to fit over the pin. Push down again, and finish driving the pin in, by using the blunt ends of the needle-nose jaws.
13. Reinstall
14. Perform the self-test for the valve:

• At the at the faucet that has the comfort valve, turn off the cold water shut-off valve.
• Open the cold water spigot. Water should flow [from the hot side!] until it becomes hot… then trickle down to no flow at all. I believe this test works even if the circulator is not active because the hot water side is under pressure.

If it fails, buy a new valve… until you get one that works. :) You win some and you lose some.

And please post a comment to reassure me that I’m not the only one on Earth who does shit like this.