Furnace Thermostat Transformer

If your connections do not match consult the installation diagram in the new thermostat s owner s manual.

Furnace thermostat transformer.

The transformer steps down 120 volts to the 24 volts the thermostat needs and sends out the 24 volts on two wires. This is what is referred to power stealing technology. These thermostats are called low voltage because they run off a transformer that reduces line voltage from 120 volts to a level somewhere between 12 and 24 volts depending on the brand of furnace you have. The first system is for the supply voltage and the other is for the secondary voltage.

24 volt control circuit step down transformer designed to power any 24 volt control system including thermostats gas valves and relays. This transformer is located inside your hvac equipment. The two 24 volt wires can never touch or the transformer. Or you can locate the low voltage transformer that powers the thermostat.

Before replacing a transformer you should use a voltage test meter to determine whether or not power is flowing through both parts of the unit properly. If you are noticing bad furnace transformer symptoms such as regular blowouts run through a basic testing procedure to ensure your 24 volt. A 24 volt transformer is typically used as a control device to turn a higher voltage generally 120 vac into a lower working voltage for switches or relays such as in a furnace thermostat transformer. The furnace transformer is comprised of two systems that make up the furnace transformer wiring.

The transformer is usually located near the heating and air conditioning system or inside of a furnace access panel. If not you may need to replace the furnace transformer which requires some basic rewiring and a general awareness of electrical work. The two 24 volt wires go to the r terminal and c terminal inside the thermostat. Lead wires for primary connections.

The thermostat tells the system when to turn on and shuts it off when the house temperature has reached the desired level. In fact many thermostats are powered by the 24 volts from the transformer. Within this low voltage thermostat category there are four major types. Low voltage thermostats are powered by a transformer that reduces the incoming line voltage from 120 volts down to a level between 12 and 24 volts depending on your furnace design.

If you are having trouble with your transformer you may have to deal with the internal wires of these two systems. Amazon s choice for furnace transformer endurance pro 90 t40f3 class 2 transformers thermostat energy limiting with foot mount 24v replacement for white rodgers emerson 4 5 out of 5 stars 145. This honeywell nema standard transformer is a multi mounting. Energy limiting meets nema standard.