Water Detection Devise

[Mathew Hawley]

I was inspecting an air handler in the attic of today’s home. The air handler had a secondary condensation pan with a water detection float device beneath the unit. My shirt sleeve snagged the float device and pulled it. The system did not shut off. My curiosity got the best of me and I raise the float device and the system still did not shut down.

My question is do these floats have to absorb water to shut down the system like a rain sensor on an irrigation system, or was the water float likely not wired properly or defective? Should I make a point to check the the water detection devices on air handlers in attics?

Thanks in advance.

[Marc D. Shunk]

What do you mean by "the system"???

Depending on the installer's preference, some of the floats are wired to break "Y" and some break "R". Either one will stop the condensation, which is the goal, but breaking only "Y" will permit the fan to continue running. This may be what you observed, and is no problem. Unless you are in a postion to operate the float and observe the condensing unit at the same time, it would be difficult to inspect this device.

[Mathew Hawley]

Thanks Marc,

That makes sense, if the condenser shut off and i was in the attic I guess the only way to tell would be to make sure the temp at the plenum did not increase after a min. or so.

Thanks again

[David A. Andersen]

If you do not have a time delay on the condensor, the lights in the attic will dim when you release the float switch and the compressor starts. If they don't, you have to find another way to prove the shut-down.

My next favorite would be to feel the warming of the suction refrigerant line at the furance (if the condensor shuts down).