Water Heater Indicator Light

I have always thought that the switch for the Suburban water heater should have an indicator light to provide a clear signal whether the heater is on or not. What I find adds to this confusion is the massive red light that is right beside the switch. I imagine the first assumption that ones mind makes when seeing that light, and it is not illuminated, the heater is off. Wrong. That light, for the most part, is an ignition cycle lockout indicator, and rarely illuminated. It would have been far more informative to make the switch illuminated, and perhaps have a smaller led for an error condition. Perhaps I'm nit-picking.

Tired of needing to look closely at the switch to determine the status, I decided to add an led into the power circuit. When the heater is on, so will be the led. I'm not the only one to have these thoughts, as a quick Google found a number of people have already made this same mod.

My local electronic supply store had a variety of 12v led lights available, so I picked some up in a variety of colours. We ended up using an amber led, which seemed to provide the best visibility. The plate incorporates the Off/On switch, and the previously described error lamp. A small hole was drilled between the two components, to allow the led to be press fit into place. There is about 1/2 inch to work with here, so a variety of small led lights could be used.

The wiring is super simple. As always, confirm everything first with your voltmeter, as sometimes things may not be wired as you believe, based on a visual inspection. Attach the positive wire from the led to the output spade of the switch, and the negative wire to the negative spade of the error lamp. It is very easy to follow that negative wire all the way to a grounding point, just to confirm things.

When the switch is moved to On, the output spade is energized, providing power to the heater, and your new led indicator. Unlike the big lamp that is there, the new little guy will stay illuminated until you turn off the heater.

A small mod to make a big difference.