I just bought a used Luxaire high efficency furnace for my garage model number PBNU-LD20N100D. The problem the previous owner said was the blower fan kept coming on every 20 minutes. He had a new circuit board installed for reeson unknown to me. I installed the furnace and noticed the blower starts running 22 seconds after the burners start up which is normal I've read for the honeywell fan limit controls. My biggest complaint is the blower fan won't kick off at the 90 deg. which is what I have the OFF set at. It will continue blowing to 55 deg. or lower. (this temperature I'm reading off the fan limit dial). I bought a new honeywell fan limit switch and still having the same problem. Any help would be greatly appreciated.
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You are using too restrictive of an air filter. If the codes you are getting off the lights says anything about a high limit this is the cause of your blower running all the time. Use a less restrictive filter or have your contractor install a media filter in the system. if you reset the furnace and it does not stop running the blower you have a stuck limit switch and may have to get another or call a service tech to reset it or replace.
I think what your saying is the humidifier runs continuously. Check the wiring diagrams on the back page of the installation instructions.
You may have to install a sail switch to control the humidifier so that it only runs when the furnace blower runs (there are a couple of other ways to do this, but on older furances, this might be the easiest (it's the method I chose).
Is the furnace fan set on auto or on. You will get better humidity if you keep the fan on. It won't add much to your electric bill because many of the newer furnaces operate the fan on DC voltage. Try it!
Neither, even if the solenoid or humidistat stick, it should always drain properly. Is the unit mounted on the cold air return duct or the supply plenum? If it's mounted on the supply plenum, the water panel might be getting blown forward and spilling the water. High efficient furnaces also can leak water on the floor if its drain is restricted. If hum. is mounted on return duct make sure drain is clear by blowing through it. On Honeywell hum's I've seen the rubber hose from the solenoid valve to the distributor tray leak too, check the rubber 1/4" hose.
It is possible that you did not set the new blower on the proper speed. Black wire is high. Blue is medium. Red is low. If the fan is operating to slow it can run to hot and trip the high limit control. Make sure the filters are clean. When the old motor went bad, the problem might not have been discovered rite away your high limit control might need to be changed.
Also anytime you work on a furnace you can kick up some dust. Always clean the flame sensor.
Commonly outdoor wood boilers use a hot water coil mounted in the ductwork above your furnace. In this application the Ruud furnace is still using its blower assembly to circulate the warm air from the boiler to your home. If this is the case. Have your heating guy install a #50 relay on the furnaces blower motor to activate your much needed humidifier. If this is not the case and your Ruud furnace is totally independent of the boiler. Still install the #50 relay in the furnace and manualy activate the fan only feature on your thermostat.
The humidifier should not turn on untill the furnace blower starts. Since the fan stays on. does the solenoid valve also stay on? If they both stay on you probably have a bad humidistat. If only the blower stays on then the circuit bourd in the humidifier is defective.
I called the service company that put in my new furnace (FAmily Heating and Cooling in Detroit, very highly recommend these people)
Anyway they sent out a second service tech who determined that I would be better off having the humidifier wired to go on whenever the furnace fan was running instead of using the humidifier signal from the circuit board on the furnace. After he changed the wiring the unit runs fine. It is pretty likely that the circuit board was bad also.