How to tell if my thermostat has low or high voltage?

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How to tell if my thermostat has low or high voltage?

The two main types of thermostats are line voltage, also known as high voltage, and low voltage. There are several ways to determine which one your thermostat is.

Line Voltage Thermostats

A line voltage thermostat ranges from 120 to 240 volts. It uses more power than low voltage thermostats because it delivers power directly to your heater. Line voltage is more commonly used with radiant, convention, or resistance heat sources. If you have baseboard or wall heaters, you likely have line voltage. However, you never want to assume.

High voltage thermostats are sometimes identifiable by removing the cover. If there is a high voltage warning, it’s a line voltage thermostat. However, a lack of warning doesn’t guarantee that a thermostat is low voltage.

Low Voltage Thermostats

Low voltage thermostats are actually more common across the country, and they’re typically used with central heating systems that run on furnaces, boilers, air conditioning, or heat pumps. Split/hybrid systems may also use line voltage thermostat.

Because low voltage thermostats only deliver an instruction signal to your heating system, they don’t require as much electricity. This leads to a crucial difference between the two types of thermostats: line voltage thermostats have thicker wires. To determine which type you have, turn off the power before removing the thermostat with a screwdriver to reveal the wires.

While low voltage thermostats typically have two wires, those wires are thinner (18 gauge) compared to the wires of a line voltage system, (10 to 14 gauge). For those people who might not be familiar with wire gauging, low voltage thermostat wires are more similar in size to angel hair pasta, and high voltage wires are thicker like linguini. Aside from size, line voltage thermostats often – but not always – have four wires.

Finally, a voltage meter can read the voltage of the wires.

Why Does Thermostat Voltage Matter?

If you want to change your thermostat, perhaps to a smart thermostat that can help them save you money through programmable features or because your thermostat has stopped working, you’ll need to identify if your thermostat is high voltage.

Knowing which type of thermostat you have can also help you troubleshoot thermostat performance issues.

Do you need help with your thermostat? We can help! Call us today at 408-295-2182.

Hiring a mechanical engineer for building retrofits, rebuilds, additions, or enhancements is the quickest and surest way to obtain the ideal facilities for supporting your operations. Are you ready to make your workplace more modern, efficient, or compliant? If so, we can help.

Call us today at 408-295-2182.


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