Honeywell L4064B2236 Fan/Limit Control Heater - Answered Questions & Fixed issues

13 years with no answer. Anyone? I need one too.

move thermostat leveler

take original honeywell model # go to honeywell site and look for original part # and it will give you cross reference #s

take cover off and hold round dial so it dosent move. there are 2 tabs in the dial . the one on the left is the low limit. the one on the right is the high limit.high limit is when the furnace shuts down 200. the low limit is when the blower will stop 90 to 100 degrees.

Maybe there is a blockage in the air conditioning coil above the furnace? This happens when people have pets, or dont use filters. Single phase 120-240 volt motors won't run backwards if you reverse the wiring that's dc or three phase, you have to check the rotation of the wheel, the right rotation is usually marked on the blower case. Some motors will allow you to change the rotation but you have to check the wiring diagram. Also use new capacitors when they go bad the motor can run backward. God luck

sounds like a run capicitor is going bad. when looking at the blower do you see like a small metal canister with wires on top.

if you have this fan switch as showen in your post you should be able to pull the on/off switch, white button, to turn it on and off to test. if it doesn't work you have no power or it is wired wrong

Hi, these Honeywell combination fan/limit controls are used for turning the fan on after the combustion changer reaches the factory setting on the round dial that you see when you remove the cover. The high limit will turn the fan on when it reaches this temperature, and off when the stat is satisfied. If the blower motor fails due to a burn out or short, it shuts the main burners down on the high limit setting. These controls can be removed and you can clean the probe which has a set of contacts at the end. Sometimes this will fix the problem. Check the settings on the dial to see if they are set right to come on, the time it takes between cycles, and the temperature they are set to shut off. This sounds as though you need to check your thermostats also. They could be a problem. You say electric heat, but then you are saying flames? If these limits have the manual fan button, make sure they are on auto. Long delays could also mean you have a dirty flame sensor located by the pilot. You can clean the metal tip with steel wool or fine sanding cloth. Short heating cycles may be your thermostats like I said before. You shouldn't have to replace the fan/limits as I told you what they control. These will cause a fan to run and not shut off after the stat is done, so check to see if they are dirty. Please keep me posted.
Shastalaker7
A/C, & Heating Contractor

I have been an HVAC repairman for 10 years and I have no idea why. Only thing I can think of is he didn`t know any better.

90 or 100 off, 140 on, 200 high limit

I just did a search-- Here is an excellent, illustrated article on the purpose and settings of this important Fan controls switch- Enjoy!

http://www.inspectapedia.com/heat/FanLimitSwitch.htm

Let me know if you have other questions on the adjustment

Thanks for asking-

Mack B

LOOKING AT THE PIC ON THIS POST IF YOU HAVE THE WHITE BUTTON PULL IT OUT. IF FAN COMES ON THEN IT IS THE SWITCH. IF FAN DOESN'T COME ON THEN YOUR FAN MOTOR IS BAD

http://www.inspectapedia.com/heat/Fan_Limit_Switch_Installation.htm#Wiring Go here, it is a super site for just about everything home related.

The dial positioning does not really matter as this is a thermometer of sorts. It is a thermo controlled switch, upon reaching the desired temperature it turns on the blower and upon cool down it shuts off the blower. The dial positioning is not necessarily critical but with him turning it he could have damaged it meaning that instead of registering at say a set 150 degrees it may actually be more than 150 or less than 150 and it will work just the set temperature may be wrong. Confusing isn't it!!

if it is the fan that wont cut off, make sure the manual over ride button,(white push/pull) is in the auto position.if the burner will not cut off then the spring on the control is failing and the control should be replaced.control can be found online or at most heating supply companies.

try checking the gas pressure might be to high or low thats what i would check first

sounds like a bad switch has to do wth your high limit kicking it out

The correct setting is whatever setting you want. Set the fan on at some temperature, set the fan off temperature at about 20 degrees below the on setting. If it still runs a short time, either increase the on time or decrease the off time. If the off temperature is comfortable to you then I would suggest increasing the on temp. Do the changes in small steps. Good luck and keep that oil burner tuned...

First thing I would suggest just to be on the safe side before you began shut power off to unit.
Remove cover on combination fan and limit.
I would set the fan on at 130-140 and fan off at 90-100 degrees. When you adjust setting grasp the outside of the dial to stop it from rotating when you are moving set point indicators. Replace cover and turn power back on. I hope this helps you. Thanks.

yes you can remove it and clean the back undo 2 screws and it will slide out