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How To Fix No Power To AC Thermostat

My thermostat has no power.

Having no power to your thermostat is actually very common during the heat of the summer season, especially in San Antonio Texas where temperatures can remain over 100 degrees for days or weeks in a row. Here are some things to check for that might save you some money! If these checks don’t solve your issue, you can always call on the pros at Air & Plumbing Today to get your AC problems fixed.

First, check if your thermostat is turned on. Although this may sound too easy, a family member might have tried to adjust your thermostat and may have accidentally turned it off. Read your thermostat’s owners manual or look up the manual online! Also, make sure your house has power and your power hasn’t been turned off either by your power company or by tripping a breaker. Make sure that no breakers in your breaker box haven’t been tripped.

If you know your thermostat is turned on and your home has power, and no breakers have been tripped, let’s dig a little deeper.

Does your thermostat use batteries? If so, go ahead and replace those old batteries. If you found batteries, replaced them and you still have no power to your thermostat, let’s continue searching for another cause.

Find your air conditioning air handler, usually in a closet inside your home or up in the attic of your home. There’s a pan under your air handler that catches water which is condensation from your inside unit. Is there water in that pan? If yes, a clogged AC drain line could be the cause. For AC units inside your home, there’s a sensor in your condensation catch pan that can sense if the pan is about to overflow with water from condensation. If your drain line is clogged and doesn’t allow condensation to drain out of the pan, this sensor will cut power to your AC unit to prevent the pan from overflowing and causing water damage to your home’s interior. The fix for “no power to AC thermostat” is to unclog the drain line, and once the clog is cleared, the water collecting in the pan will drain out and the water pan sensor will restore power to your AC unit, also restoring power to your thermostat.

Clogs in your AC condensation drain line can be caused by many things such as mold/mildew buildup, algae buildup, debris from recent projects within your attic such as sweeping, newly installed insulation getting in the lines, debris from a new roof that was recently installed, debris from pests, wildlife or rodents in your attic, etc. Some clogs are easier to clear than others. Many clogs can be cleared by simply pouring bleach down the drain lines. There are some AC drain lines that run to a sink drain inside your home. Clogs in that sink drain may also clog your AC drain line at the same time. A few inspections may reveal the exact cause and allow you to fix it yourself. But other, tough to find clogs may need a professional HVAC technician with a compressor to clean the drain lines to restore your AC back to running condition.

We hope these few suggestions help you find and fix your no power to the thermostat problem. If you can’t solve this problem on your own, call Air & Plumbing Today at 210-519-5959 and we’ll send a friendly Air Conditioning technician to your home quickly to solve your Air Conditioning problems.

How to fix no power to the AC thermostat
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