Furnace Comes On When Circuit Breaker Turned On To Central Unit

Janitrol Model A36-15 Schemtaic here

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The optional Emergency Heat Relay is installed, and the airhandler is wired for slow speed.

What causes the electric heating elements in the unit to heat up and the blower fan to come on when the 2 circuit breakers on the unit are flipped on, with the thermostat set to Off?

Reply to
nowforsale
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Hi, And it keeps running like that? Or I wownder if the thing is in test mode?

Reply to
Tony Hwang

Either your heat sequencer is stuck or it is getting 24 volts from somewhere. Check and see if you have 24 volts to the sequencer. If not, tap on the sequencer with a screwdriver handle and see if it goes off. Post the results and we can go from there. Good luck Larry

Reply to
lp13-30

Am not familiar with what the sequencer is or how to check to see if it is getting 24 volts. Is the sequencer the thing with M1, M2, M3, M4, M5, and M6 on it?

Tried tapping on the 3 things now colored yellow in the schematic here

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Emergency Heat Relay, the Blower Time Delay Relay, and the other thing), to no avail, the furnace and blower sitll come on when the circuit breakers are flipped on.

Reply to
nowforsale

the motor in this unit is 1/3 horsepower and the blower is wired for slow speed, is there way to reduce the speed even more? maybe even have it to where the speed could be adjusted in a variable fashion, like maybe hooking up a light dimmer switch inline on the motor wiring?

Janitrol Model A36-15 Schemtaic here

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Reply to
nowforsale

changed the sequencer with a new one but problem still exists

haven't yet checked to see if the sequencer is getting 24 volts; if it is getting 24 volts, where would it be coming from? isn't it supposed to get 24 volts from the 24 volt transformer?

Reply to
nowforsale

The sequencer is nothing but a switch to turn the heat strips and blower on when it gets 24 volts it. It is called a sequencer because it brings the strips on one at a time (in sequence) rather than all at once, mainly to keep lights from dimming etc, as itwould do if all came on at once. Get a voltmeter and check between the white and common thermostat wires at the air handler. Common should be blue. With the thermostat off, there should be 0 volts. When he thermostat calls for heat, it sends power from the red tstat wire to the white, putting 24 volts to the sequencer, bringing the strips and blower on. If it is getting

24volts, disconnect the white at the thermostat and check again. If 0, it is getting the voltage from the thermostat, if still 24, it is most likely a short in the thermostat wires. Is this a heat pump, or just electric heat? If it is, then it could also be shorted in the thermostat wires going between the air handler and the ouside unit, or possibly a bad defrost control board in the outside unit. Just go by the processs of elimination til there is no 24 volts to the seq. Let me know what you find. You in or near San Antonio? Larry
Reply to
lp13-30

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