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likely need to change the thermostat configuration to electric rather than gas. does it heat when you put the fan in the on position and call for heat?
The control fuses keep blowing tells me one or more of the control that operate the control on 24 volts is malfuctioning. Most controls operate at about 5 watts and on a clamp on amp meter normally pull about 0.2 amp (p = current x voltage, 5 watts = 0.2 amps x 25 volts) I install 75 watt 24 volt transformer with a resettable overload to save on fuses. I reset the transformer and quickly go to the controls and determine the amp draw. When I find the one >0.2 amps I found the problem. The things to check is the emergency heat sequencer, fan control sequencer, reversing valve for heat pumps, main contactor on the condensing unit and any other 24 volt control loads. I have had to replace the themostat wire because the increase current for the thermostat wire can cause the entire length of wire to form a long heater and cause insulation degradationa and cause the thermostat wire to short out and blow the fuses.
Hope this helps
do you have the lower door in place tight ?? because there is a door button switch. so if its not pushed in all the way you would have no power at furnace. also make sure nobody turned off the on off service switch usually above furnace or sometimes one at top of stairs and one down by the furnace .if those suggestions don't work you might want to turn each breaker off then back on incase one is tripped. if that don't work check for 120 volt at your fan timer board also it may have a automotive style fuse on the board which if blown it wont do anything. if there is 120 volt at board and the 24 volt circuit fuse is good its probably the fan timer board.
Control fuses only blow with a 24 volt problem. Make sure that you replace it with a fuse NO LARGER than 5 amps.You could have a thermostat wire pinched or some wire touching the cabinet inside the unit, but it is a 24 volt problem.
Most of the humidifiers are run by 24 volts AC. disconnect the power wire to stat on circuit board and check there with meter and connect to low voltage ground for 24 volts, I'm assuming the two wires that power the humidistat are red and white.typically red is used for power. most likely you have power if the red for the stat is connected to the W on the board and the heat works, but the humidifier only works while heat is on.the next thing in line is the humidistat , it's a switch so if there is only two wires going to it take them off the stat and connect together, if furnace is on heat and running and stat wires are connected it will send power to water solenoid, if its not working yet the problem lies in the water solenoid if you have 24 volts at the two wires at solenoid.check while disconnected, do not connect those two wires together or a 3 amp fuse will blow on the furnace board. if you have 24 volts there then the valve may be bad or the valve may be stuck or clogged, loosen water supply line to make sure water is getting to valve. I spent many years working in the HVAC industry.
Hello, The first thing you need to check with a multimeter is if you are getting 24 volts between the R AND C terminal on the intergrated control board. If not than the transformer is blown and needs to replaced or the fuse on the control board has blown and will need to be replaced. When check for 24 volts at the R and C terminal make sure the door switch is pushed in, u can just use electrical tape to temporaily hold the switch in. If you are getting 24 volts at R and C and notthing continues to run than the intergrated control board is most likely the cause and must be replaced.
Try the fan switch inthe ON setting rather than the AUTO setting, if it runs, power, both low(24) and high(115 or 230) are present. if not, check breakers and fused outlet if a split system furnace, read for 24 volts at red and common on low voltage terminal board where thermostat wires go on the furnace, if no 24 volts there and poers entering furnace, transformers bad.
double check your wiring. R terminal on the furnace will provide 24 volts to the t-stat. W terminal in the t-stat will send 24 volts back to the furnace W terminal to turn on the heat. G terminal in the t-stat will send power to the G terminal in the furnace when the t-stat is switched to fan on. Y terminal in the t-stat will send power to the Y terminal in the furnace which in turn will send 24 volts to the A/C outside. The C terminal in the furnace should be connected to the c terminal in the A/C outside as well as to the T-stat. Check the fuse again
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