Fan is always on, HELP! version 4.3


 

John Bencic

New member
Hello,
I have just completed a new version 4.3 heatermeter with an adapt-a-damper and thermocouple option. My problem is that no matter what setting the controller is on the fan always blows at max speed and never shuts off. The servo appears to be working correctly. I followed instructions on git hub for wiring to the rj45 jack and the only wire I was unsure about was the blue wire from my blower fan as I was sent the one with three wires and not two. I tried not using it at all and also connecting it with the fan 12V red and in both scenarios the fan is always on. I am sure it's something simple I missed somewhere but I can't seem to figure out what went wrong.
 

John Bencic

New member
I have read as many posts that seem to address this issue and will be testing the Q1 & Q3. I have already ordered replacement bs170 and Power p mosfet and will probably replace those along with the 220uH inductor and 2.2K resistor just to see if any of those were the problem and see how things go.
 

GSpinelli

TVWBB Member
To he blue wire is the fan tachometer. Good chance you blew the tachometer output when you hooked it to 12V as the are normally open collector outputs. The fan should still work fine.
 

John Bencic

New member
Oh I see, oops. I will leave the blue wire disconnected and see how things run after my replacement parts arrive for the PCB.
 

John Bencic

New member
Oh I see, oops. I will leave the blue wire disconnected and see how things run after my replacement parts arrive for the PCB.
Follow up resolution. I replaced the bs170 Q1 and wired up the fan leaving the blue wire out and everything is working perfectly. Thanks
 

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