58 Series Fan/Limit Control


Old 10-19-00, 05:08 PM
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On my 58 Series Fan/Limit Control I see two setting. What is the setting on the inside helix for?

This is a setting that is on the inside metal stick portion that goes into the furnace/flame area. The marks go from 250 down to 100 something?
Is this incase the blower does not come on, the gas will shut off as a safety measure?

I believe this fan/limit control was made by Carrier. What is the recommended temperature setting?
The old one says 230, the new one says 175 and it came that way out of the box.
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Old 10-19-00, 07:30 PM
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Hi Gwen:

I think first we need to sort out some terminolgy. A FAN & LIMIT control will have 3 settings. The LIMIT setting is a high temperature limit that will shut off the burners if the furnace gets too hot. The FAN has two settings- the higher of the two turns the fan on as the furnace heats up and shuts the fan off as the furnace cools down after the burners have shut off in response to the thermostat. you can buy a FAN control which has only the fan on/off function and you can buy a LIMIT control which has only the high temperature limit function. Now. when you say that the old one says 230 and the new one says 175, do you mean that these are the numbers that the indicators are set to or do you mean that this is the highest number on the scale? If you mean the current settings, I would set the new one to where the old is set for. If the new control won't go higher than 175, you probably have the wrong part. It's very important to compare the length of the insertion tube between old and new. The new control want to be the same length. Also, make sure the new control has all the functions of the old one. BTW- Carrier didn't make the part. it has their part number on it and maybe even came in thier box, but it was most likely made by Honeywell or Cam-Stat. If it didn't come with any instructions, go to http://hbctechlit.honeywell.com/ type in fan and limit control and search. Thanks. John.
Old 10-20-00, 03:09 AM
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I was told my the repair man last spring that I should convert to a Honeywell, but it would cost me a lot of labor. I have a Camstat in there now. I did go to the web site you recommened for Honeywell instructions. None of those picture resembled my Fan/Limit Control. It was a great site and I thank you for sending me there. My fan/limit has one setting on the outside, it says fan off and ranges from 85 deg to 120 deg. The long square metal piece that goes into the Plenum? is 7" long and 3/4 of an inch square. Inside there is a screw and slider set up. The setting on that range from 250 down to 125. I believe my terminolgy was correct when I said I had 2 setting instead of 3. My original question was to confirm that the setting inside of the Plenum? was the Limit setting, as my I am possitive I have a combintation Fan and Limit control all in one.
To answer your question, I was referring to the numbers that the indicators were set to, not the hightest number on the scale.
The factory has set the one unit to 250 deg. an the factory setting on the other was dialed in at 175.

I do not have the original part that came out of the Bryant/Closet furnace. But I did re-purchase the exact same part that the repairman put in last spring. This is the third unit. As the previous two, the fan would not shut off unless you rapped the switch with the end of a srew driver. I've been doing that for the past month.
I am wondering if second repair man purchased the wrong part because the New part says for 58 series models and my furnance model starts with a 39.
I can sent you a picture of my new 58 series furnace fan/limit control part if you would like.

The problem I am currently having is the fan now shuts off 1 min after the flame goes out leaving what I think is too much heat inside the furnace. Will adjusting this inside switch solve my problem? The off setting on the outside is set for the lowest possible, at 85 deg.

my e-mail address is [email protected]
Old 10-20-00, 03:16 AM
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P.S. I am using a LUX Programable Thermosat model 1500, after reading some of the previous posts, could that be my problem?

It is one year old, It has brand new batteries and works wonderful. I installed it during the second Fan/limit control change.
Old 10-20-00, 04:31 AM
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What you have is in fact a Fan limit control, with a fixed Differential...I would leave the high set at 175, as for it sticking in the on possition, its possible to have a bad one....are you sure its not hitting anything in the furnace?... the adjustable slide is for the high limit and will cut the burner off at the set temp.
now let me get this straight, you have at least four wires going to this.... are they hooked up right, like the fan wires to the fan side and burner wires to the limit side..
Old 10-20-00, 05:01 AM
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There are 6 wires going to it.

We do have a skimatic, but the furnance is 17 years old and we can't make out some sections.

The skematic doesn't seem to look like the fan/limit that is in there either.

Thank you for your help. I will study it the diagram again after work tonight.
Old 10-20-00, 03:52 PM
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Hi Gwen:

Now I understand better. You have a Bryant furnace but the part is for a Carrier. The 58 series is Carriers designation for furnaces while 39-something is Bryants designation. Since Carrier owns Bryant, the two parts are probably the same. As for the settings, the adjustment on the inside is the high temp limit and the the adjustment on the outside is the fan off temp setting. Apparently, the fan on temp is fixed. Frankly, I think your best move is to convert to the Honeywell control. I don't think the problem is with the Lux thermostat. The only reason I recommend against them is many folks have reported problems with them and my experience is Honeywell & White-Rodgers are better products. If yours is working fine, we don't want to fix something that isn't broken. Just to make sure we are on the same page, did you download the instuctions for a Honeywell L4064 fan & limit control? It would be document # 68-0024. Notice the Super Tradeline model, L4064B. Super Tradeline is Honeywells way of saying this control has the widest replacement application range and contains all the accessories that make it so. The only difference among the B models is the length of the insertion probe. If your current one is 7-1/2" then you would use the 8" Honeywell model. The only glitch I see is the ST has a larger case than the regular Tradeline model and if space is tight you may have to make a different choice. The case dimensions are on page 4. Also, you need to look closely at your existing wiring and the wiring diagrams for the Honeywell. It's important to know if the jumper stays in or has to be taken out. Once you renove the jumper, you can't put it back in but you could hard wire a jumper if you remove it by mistake. If you leave the jumper in and it should be out because the limit is in the low voltage circuit, you'll probably burn out the transformer and the thermostat, so this point is very important. Let us know how you make out or if you need further help. Thanks. John.
Old 10-21-00, 06:55 AM
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You are correct it is a Fan and Limit Control. I like the honeywell better but your furnace was designed with and tested with the CAMSTAT FALT-5 or 7.
I recommend using what the manufactor designed and tested it with. If something goes wrong there are no liability issues.

The six wire switch, Camstat FALT- 7
The setting on the inside is the HIGH LIMIT, set that to the limit temp on the furnace name plate.
The outside temp off switch is what turns the fan off when the furnace is cooling down.

Now the extra 2 wires are to operate a heater(on the switch itself) to turn the fan(furnace blower)on quicker in anticpation of the heat being turned on. this helps with efficency.

Keep having problems with the switch going bad. Possibly it is someting else causing the switch to go bad or get stuck,
Say the filter is plugged
the evaporator coil is plugged
motor on the wrong speed, too slow
too many registers closed
inadequate ductwork
oversized furnace
Need to check the tempture across the furnace
and see.

Good Luck
Mr Foster
Old 10-22-00, 10:24 AM
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I have a manual three speed blower. Yes, the setting has been on the slowed speed for the past 15 years. I will up it to the middle speed. So perhaps my motor was on the wrong speed.

The Byrant Dealer was supposed to have done a thorough cleaning. Where is the evaporator coil so I can see if it is plugged?

During one of my many service calls, one repair man did remove a jumper, between the 2nd and 3rd replacement switch. I have the jumper, but I have no idea where he removed it from. I have no idea if he removed it from the Limit/Fan switch or some other place on the furnance.
Old 10-25-00, 05:35 AM
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My problem may be solved. I called the Bryant Factory and they gave me the phone number for the Northeast Carrier Distributor. Turns out I have been running the wrong Fan/Limit switch. He gave me the correct part number. I'll try that and see what happens. Many many thanks to all of you who helped my understand how it was supposed to have worked.

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