One of the benefits you’ll enjoy from an electric furnace is its longer service life, usually five years longer than a gas furnace. The reason for this longevity is that electric furnaces don’t suffer from wear and tear due to combusting gas and the chemical reactions between gas and metal. They also need fewer repairs because of this.
However, there are special components in electric furnaces that can go a little … haywire … and we want to focus on one of these components today: the sequencer.
The Job of the Sequencer
An electric furnace works by sending electric currents through a series of heating elements. The current causes the elements to glow hot and transfer their heat to the air pushed through the furnace and into the ductwork.
An electric furnace contains multiple heating elements, but if all of them activated at once it would overload the electric circuit. The heating elements need to turn on one at a time, and this is where the sequencer comes in.
The sequencer contains a series of conduits that route the electrical power entering the furnace to the heating elements, but in a staggered way. When electric current enters the sequencer, the first conduit will direct it to the first heating element. When that heating element reaches a set temperature, the sequencer allows the next conduit to open up, allowing electricity to flow to the next heating element. This process continues until all the heating elements have come on or the thermostat has signaled to the furnace to stop the heating cycle.
Earlier this year, we wrote about how an electric furnace can trip its circuit breaker. A broken sequencer is one of the common causes of this problem. The sequencer can malfunction so that it doesn’t stagger the heating elements but instead allows them all to turn on at once—a quick way to overload the circuit and cause it to cut power to the furnace altogether.
On the opposite end of the problem spectrum, a failed sequencer can prevent any electrical current from flowing to the heating elements. The furnace comes on, but no warmth comes from it. If you have a furnace that is blowing out room temperature air when you set it to heat, a problem with the sequencer is a possibility.
Along with these “too much or nothing at all” problems, a sequencer can start to corrode with age and some of its conduits fail. In this situation, you’ll have a furnace that will turn on some of the heating elements but not all of them. The last ones may not come on at all, and as a result your house won’t get the amount of warmth it needs.
If you suspect you’ve got a bad sequencer in your furnace, don’t attempt to repair it yourself. This is a precision electrical component, and you’ll need our assistance to repair or replace it.
Cool Touch Air Conditioning and Heating is your HVAC contractor serving the Phoenix Metropolitan Area. Kick back and relax—we’ll keep you cool.