question for HVAC guys
Well I'm "late to the game," LOL
If you can post some photos of the inside of the furnace control panel, that would help, and of course the model no
Here, generally is what happens in an electric furnace. Most "old school" electric furnaces have a set of breakers in / on the furnace itself. These can of course trip, obviously not the problem here.
The stat is supplied 24V from the red wire, coming from the transformer. red to white switches on heat, Red to green brings on the blower, for AC and for "summer fan" (blower only) and red to green (blower) added to Red to yellow brings on the condensing unit
Usually red to green should bring the blower on instantly, IE a relay and not a sequencer. However, this is NOT what brings the blower on for heat. In heating, normally only red to white is made, and the blower comes on delayed. In some units, the blower is delayed by a sequencer, in some, brought on by a temperature switch (fan switch) and in newer units, controlled by a solid state board......delayed.
Electrics are normally "staged" so that the heating elements come on one's or two's at at time, devices known as "heat sequencers." These, really, are somewhat reliable, and somewhat troublesome. All these things are, simply, are a 24V heating element, with a thermal switch on top. Depending on how many elements in the furnace, you might have a couple, or several, and some are double pole
The thermostat normally runs one or two sequencers, many times one, and that sequencer "daisy chains" to fire the next sequencer. When the element in the sequencer, triggered by the wall stat heats up, the thermal disc switch on top trips shut and turns on the blower and the first set of elements. When the next sequencer closes, then the next set of one or two elements kicks in.
Any how after all this ranting, what happens is THESE THINGS FAIL and get sticky and intermittent. Here's a working diagram of one:
Bottom most connections are the 24V heater, top set is last to switch, and middle set is contacts which close first
Well I'm "late to the game," LOL
If you can post some photos of the inside of the furnace control panel, that would help, and of course the model no
Here, generally is what happens in an electric furnace. Most "old school" electric furnaces have a set of breakers in / on the furnace itself. These can of course trip, obviously not the problem here.
The stat is supplied 24V from the red wire, coming from the transformer. red to white switches on heat, Red to green brings on the blower, for AC and for "summer fan" (blower only) and red to green (blower) added to Red to yellow brings on the condensing unit
Usually red to green should bring the blower on instantly, IE a relay and not a sequencer. However, this is NOT what brings the blower on for heat. In heating, normally only red to white is made, and the blower comes on delayed. In some units, the blower is delayed by a sequencer, in some, brought on by a temperature switch (fan switch) and in newer units, controlled by a solid state board......delayed.
Electrics are normally "staged" so that the heating elements come on one's or two's at at time, devices known as "heat sequencers." These, really, are somewhat reliable, and somewhat troublesome. All these things are, simply, are a 24V heating element, with a thermal switch on top. Depending on how many elements in the furnace, you might have a couple, or several, and some are double pole
The thermostat normally runs one or two sequencers, many times one, and that sequencer "daisy chains" to fire the next sequencer. When the element in the sequencer, triggered by the wall stat heats up, the thermal disc switch on top trips shut and turns on the blower and the first set of elements. When the next sequencer closes, then the next set of one or two elements kicks in.
Any how after all this ranting, what happens is THESE THINGS FAIL and get sticky and intermittent. Here's a working diagram of one:
Bottom most connections are the 24V heater, top set is last to switch, and middle set is contacts which close first
