Carrier 58SS 58GP 3 wire pilot assembly operation

[@SBbild]

I'm a younger tech working on old weathermaker 9200s and this helped me, just wanted to thank you, buddy.

[@grayfurnaceman]

Welcome GFM

[@grayfurnaceman]

I think some of the later Essex valves had the pressure switch too. It had external wires to it and the pressure switch was one of the common failures in the valve. Thanks for the thoughts. It brings back some memories of the problems with that furnace. GFM

[@mechacc2000]

Nice basic explanation. That is the older style Essex gas valve which uses a holding coil to keep the pilot lit when the pilot moves to light the main burners. The replacement White Rodgers has an internal pressure switch that keeps the pilot solenoid energized. If incoming gas pressure drops to low during operation the pressure circuit opens and the burners will go out. The pilot relights when pilot burner cools down and then recycle off until incoming gas pressure stays in range.

[@amoore2165]

You helped me out with these videos. Thank you!! Had to replace my 3 wire pilot.

[@grayfurnaceman]

Welcome GFM

[@grayfurnaceman]

First some of your questions may be answered by this vid. "Carrier BDP 398AAW, 394GAW model plus others". Most of these furnaces have a fan control board but it has nothing to do with flame safety. The flame safety is a combination of the gas valve and the pilot assy. On a call for ht, pilot gas comes thru. A very small amount. The main gas can't come on til the pilot proves. There is no retro kit for these. The pilot assy is the most common failure. Hope this helps. GFM

[@RetroDave2]

Is there a kit to refit these three wire systems with a more modern Hot Surface Ignitor? The new three wire replacements don't seem to last like the old ones did.

[@christopherbroughton3057]

My pilot would not stay on so I purchased a new 3 wire pilot assembly and replaced the failed unit. When I installed the new 3 wire pilot assembly I reused the igniter. When I turned the furnace on nothing, not even an attempt to spark. I removed the new unit and reinstalled the old failed pilot assembly it would try to light but of course it wouldn't stay lit. Is it possible I got a bad part because it won't even allow it to go through the sparking cycle with the new part?

[@leeb.7188]

I have a 1986 Carrier 58GS 125 BA, model 150. It has been dead for 3 cold days. First I replaced the electric pilot assembly, then the igniter, then the Capacitor. Nothing changed. Finally I replaced the High Limit Thermostat. Success! My only concern is that when it finally lit up, the flames came whooshing out and singed my flannel pajama pants before I could jump back. I didn't touch or adjust the gas valve, so I'm thinking maybe when I replaced the pilot assembly I set it a bit too low, so there was too much gas built up before it lit? I don't know, but I was uncomfortable so I shut the whole thing down and will suffer another cold night and look at it in the morning. I'm going to call one of these HVAC companies that are advertising winter service checks, as they will know how to test and adjust it. But I can't afford a new furnace right now or major repairs, so I bought a box of all the parts and figured I would just keep changing them until I got the dang thing going. I'll return the ones I didn't use. Anyway, I hope this helps someone.

[@grayfurnaceman]

Not unless you have a 15,000 volt meter. The way I check them is on a call for heat, I check the 2 input terminals. If there is input and no output, the ignitor is bad. Hope this helps. GFM

[@dcccs]

Hi, I have a Carrier 58GSC065 series 130 furnace (probably 30-40 years old) that stopped working recently. I noticed that the pilot light never comes on and there is actually never even a spark that occurs. When I set the thermostat so that heat should come on and turn off/on power to the furnace, nothing happens although I can "hear" power going to the furnace. I also tried to manually light the pilot, but this doesn't work either. Would this indicate a problem with the pilot assembly or the HSC igniter/lockout control unit (1007-100 LH33WZ512A part) that the pilot assembly is connected to via the red wire? Actually, I'm not clear which way power is traveling for the red wire so could you clarify this? The igniter/lockout control unit was replaced a long time ago for some furnace issue, but I don't know the details. I'm not sure how to troubleshoot whether the pilot assembly or the control unit should be replaced. Thanks in advanced for any suggestions you can make.

[@grayfurnaceman]

Not that I know of. The only way I can think of is to use an S8600 honeywell spark ignitor retrofit kit. This includes the gas valve and an adaptor for the pilot assembly. A pilot burner will have to be added and mounted. This could only be done on a unit that does not have an inducer. Cost may be an issue here. GFM

[@fastjulio]

Do these older models have a flame sensor? My furnace turns on for about a minute then shuts off. Then attempts to turn on again, but only hearing the ignitor clicking noise. I did a little research and thought maybe my unit wasn't getting enough air flow so I replaced the filter, then went on to try to locate the flame sensor without any luck. Thanks in advance.

[@grayfurnaceman]

The pilot assembly is the flame sensor. You probably have a failing pilot assembly. GFM

[@ufher25]

how do u installed the gas valve, the valve its diferent EF32CW233 form the old one wiring its my question

[@xLoZxPickle]

Hello. Quick question I'm hoping you might be able to help with. I have a Carrier furnace with this same 3 wire pilot assembly. Just the other day out of nowhere, I wake up Friday morning, turn on the furnace and coldish, room temperature air is coming out of the vents. After some research, I attempted to replace the pilot assembly. After successfully switching out, still the same thing. With both the old and new assembly, I noticed the pilot light comes on, but the chambers never fill with fire. I'm thinking there's something wrong with the sensor that tells if the pilot light is on. Can you offer any help or advice?

[@grayfurnaceman]

If the pilot is switching, it is probable that the gas valve has failed. Fairly complicated diagnosis here. If you are not confident, either replace the valve or call a professional. Hope this helps. GFM

[@xLoZxPickle]

+grayfurnaceman You were right, it was a gas valve failure. Called a guy to come out and look at it and he replaced it for me. Thanks for the help!

[@grayfurnaceman]

+xLoZxPickle welcome GFM

[@obsidiana07]

My furnace makes a buzzing sound every ten seconds but when I turn on my heat it still works. Any idea what it could be?

[@ntheq3982]

Gary... I see you have several videos on these old 3-wire pilot assemblies so you seem to be the most experienced on these old types. I'm troubleshooting the 3-wire sw because the main gas never turns on after the pilot runs. The igniter and pilot work correctly as scheduled but the main gas never comes on which leads me to believe the bimetal sw is not functioning properly. The gas valve and MGV works fine because I jumped across #3 HOLD contact to the #1 MGV and the MGV opens and fires up the main burners. So, even after the pilot runs, up to 3 minutes, the main gas to the furnace never starts up (no 24v on WHITE wire). I did a continuity check on the 3-wire pilot sw and I get continuity on the GREEN and YELLOW wires which leads me to believe that is the normal position when the pilot is NOT running. There is no continuity between the GREEN and WHITE or the YELLOW and WHITE. I suspect that after the pilot heats up the bimetal sw and closes the contact I should get continuity between the YELLOW and WHITE but I'm not sure, maybe GREEN and WHITE. This is where I hope you can guide me. Once I clip together the push-in wire harness clip I can't test the continuity on the WHITE wire to see if when the pilot heats the bimetal sw that the contact jumps over to the white wire. I did buy a new 3-wire pilot light assembly but I'm thinking it's bad but don't know how to test it because i can't get to bare wires once the wire harness is pushed in on the connector clip. I want to stay as close to the pilot assembly as possible. Here is a link to the Carrier schematic: www.manualslib.com/manual/748163/Carrier-58gs-Series.html?page=5#manual

[@grayfurnaceman]

This sounds like you are over thinking this. Have you installed the new pilot assembly? GFM

[@ntheq3982]

Yes, I did buy & installed a new one. Maybe I am over thinking but it still doesn't work automatically with the new 3-wire pilot. It seems that everything works properly up to the MGV opening. That is why I think the bimetal sw isn't making contact to energize the MGV. I replaced the limit sw and the motherboard a month ago because I could only get the MGV to stay open with the WHITE wire pulled off the motherboard . So that basically leads me back to the pilot sw because it's the only part that controls the MGV.

[@ntheq3982]

Point is, everything works IF I jump off the HOLD side on the gas valve. The spark sparks, lights the pilot, spark drops out. If I then jump the MGV the burners light off and run until the temp gets to the thermostat setting and shuts off. So, I wanted to test the bimetal sw function before I buy another pilot sw

[@grayfurnaceman]

@@ntheq3982 Terminals 1 and 2 on the gas valve are the main gas. When the pilot switch moves, you should have power between terminals 1 and 2. If you have power and the gas valve does not open, the gas valve is the problem. GFM

[@ntheq3982]

The gas valve works. As I said I did jump from the 4 yellow to the 1 white contact on the top of the gas valve & it opens. What doesn't work is the automatic function going from pilot burning to MGV open. Therefore I'm thinking the bimetal sw inside the pilot is NOT bending over to contact the white wire (in the pilot sw) as it should when it heats up... because the gas burners never AUTOMATICALLY open. The gas burners light IF I jump it. I'm just trying to get a way to test the bimetal pilot function.

[@TrabucoDom]

I believe my 3-wire switch is bad because it never sends the 24v to the main valve. I removed the original switch and put a continuity tester (dvm) across green -to- yellow wires which should be normally closed, and they test fine. Then I heated the bi-metal switch on the stove flame and the n/c switch never goes to "open". Also, yellow-to-white is normally open, I believe. But never goes to "closed" when heated. Since I think this proves the switch to be a bad one, I ordered one. When I installed the new one, furnace still did not work (symptoms are spark goes on, pilot then lights, but main valve never opens, I believe due to not getting 24 v from switch). So I took out new switch and tested it in the same way. The new one had green-to-yellow as n/c and did go to "open" when heated on stove. But the yellow-to-white n/o contacts still did not close. I ordered another switch and decided to test it on the stove before installing it. It does the exact same thing as the first new switch. So my question, is heating the bi-metal switch on the stove a valid test with the dvm and I have another bad switch? Or does it actually need to be installed with gas running through the pilot for the switch to work properly? I ordered a 3rd switch from another source, and same effect, n/o does not close when heated on the stove. Bad switches or invalid test?

[@TrabucoDom]

I just opened my original defective switch and cleaned the contacts. When I reassembled and tested it on the stove, it performs as expected, the green-to-yellow n/c then opens when heated, and the yellow-to-white n/o went to closed when heated on the stove. So I guess the 3 new switches I received were all possibly bad. I'll re-install my original that I just repaired and see what happens.

[@JKraylon]

I have a question grayfurnaceman, I have a similar model Bryant and the ignitor keeps sparking long after the pilot lights and the main gas turns on. It seems to work besides that. What feedback, if any does the pilot assembly use to control the ignitor? It is loud and seems unnecessary to spark for several minutes.

[@grayfurnaceman]

The spark ignitor gets feedback from the pilot flame to shut itself off. Sometimes either the spark probe gets dirty or the electronics inside fail. You can clean the probe with sandpaper. It causes no problems but the spark ignitor may fail earlier. GFM

[@JKraylon]

@@grayfurnaceman thank you for your reply! The maintenance guy assures me this is normal operation but he isn't an HVAC tech by any means 🤦‍♂️

[@larryfisher5198]

This same type ignition system I've found several delayed ignition issues coming on with a boom. Every one I found was using a Robert shaw valve with a black on off knob. It would only show itself when a dirty pilot failed to light in a timely manner and somehow within the valve it would power the main valve coil even though the bi metal hadn't switched. So burner gas dumping and ignitor sparking it goes boom. After finding several bad ones on delay ignition calls I subsequently tested every one I came across and sure enough found more but hadn't shown themselves yet as pilot was lighting ok. If you see one that pilot lights then main valve opens within 15 seconds or less beware the valve. That bimetal switch takes longer than that to power the main valve.

[@larryfisher5198]

Addendum to above if memory serves even after main valve coil is powered there was an additional built in 15 seconds or so delay in the valve before it opened. All this in addition to the delay of the bimetal heating to switching temp. Again this was only on the Robert Shaw brand valve with the black knob.

[@grayfurnaceman]

@@larryfisher5198 Good inför. GFM

[@jennifercartell2956]

Grayfurnaceman: My furnace ignites, heat comes out briefly and then it shuts down after a few minutes. It has been working great all winter and just started doing this. Ideas?

[@grayfurnaceman]

Give me make and model# GFM

[@iccf-21conference76]

@@grayfurnaceman I have this same issue with a Carrier 58GS style system. Thermostat is good, replaced limit switch L170-40. Ignitor lights pilot, pilot lights main burner. Main burner cycle turns on fan, but burner goes off after a couple of minutes. Fan continues until lower limit. As soon as fan goes off, pilot goes back on.

[@jpersonette11]

Hi Gary or anyone else reading. Furnace will only kick the blower on and only cold air while on heat. No spark, no burners, nothing. Just replaced the spark igniter and the 3 wire pilot but got the exact same scenario. Any thoughts or ideas where to check next would be so greatly appreciated. Cant thank you enough. Hope you and your family are doing well. :) Jp

[@usahoangsatruongsa]

" Furnace will only kick the blower on and only cold air while on heat." Check limit or roll out switches They're probably open and did not allow the heat on That's a safety feature of all heat furnace machine. You need to RESET it first then try to turn on your heat again. You HAVE TO find what the reasons your limit or roll out switches tripped .Check for dirty air filter weak blower motor gas line pressures, heat exchanger cracked etc...etc...otherwise the problem will come back.

[@fineskills1]

Hi, I have one of these day and night three wire with intermittent running. I have replaced the three wire pilot with brand new Pilot that lights every time, but it does not release the gas all the time. I usually hear very quick rapid clicking, like 2 taps coming from the gas valve (?). I try to put the meter and find the pick and hold terminals. Should they have power? I often have fluctuating voltage, sometimes 20-38 with it running. Is this worth a part (gas valve?) I can gamble on or does this thoroughly have to be tested? The pressure switch appears to be good, because the draft fan runs consistently. I did bypass the pressure switch and that didn’t help anything. Please help, wife doesn’t like burning wet wood 😝. Thank you!!

[@grayfurnaceman]

This is probably a bad gas valve. Very common if the pilot switch is working. GFM

[@nicholaspeters558]

For some reason I can't watch these video so I'm not sure if you covered this but what Is the purpose of the little nipple inside the igniter where the gas line goes on this model. I lost mine down the main drain and past the trap. What if I don't use it?

[@grayfurnaceman]

That part is essential. It is the pilot orifice. Without it, the pilot flame will be far too large. GFM

[@yacapmeluv]

I have identical pilot assembly as showed on this video. I replaced the whole pilot assembly and still I don't get spark to ignite the pilot. Everything are connected as it was before replacement parts installed. Pilot did not light up? Please need help.

[@grayfurnaceman]

+yacapmeluv The high tension lead goes from the pilot assy to a box that has 2 24 volt wires going to it. Check to see if voltage is to the 24 volt wires, If so and no spark, the box has failed. Hope this helps. GFM

[@chulee8148]

i love your show thank you and i order this 58SS 58GP 3 wire pilot assembly do you have how to install video? reason i order because it turns on and off 6 or 7 times before it got steady fire and i cant find buring sensor on my unit

[@regularcabdad4474]

Did that work? Thanks in advance

[@R0N1NPANDA]

@grayfurnaceman , I have a similar old 58GS050 furnace. Just recently noticed that twice after the furnace was off for longer time (a couple hours), the pilot fail to get the main burner lit. It feels like the pilot was locked out, as if I reboot the system via Nest app, no sparking. After a few minutes, reboot, the pilot is on instantly, with solid blue strong fire, but the igniter seems to spark repeated still, until the main fire is on. Also it takes some good 30s to get the main fire lit with the pilot flame heating that "metal rod"(thermocouple?) and slowly turn it red. Where should I start about cleaning (or replacing?) Thanks in advance.

[@grayfurnaceman]

The first place I would look at is the pilot assembly. Most common failure in these type furnaces. GFM

[@R0N1NPANDA]

@@grayfurnaceman Thanks. I watched your video on the assembly and realized my misunderstanding. Apparently the "bi-metal" which was down inside the assembly was the switch for the main gas. Is the "metal rod" sits above the pilot flame just the pilot safety? I initially thought I could just clean that like the old type thermocouple, but if it's the safety then does not match with my symptom. So I guess, I need to remove the pilot gas tube nut, remove the assembly out of the way and clean it up first. Where can I find the OEM model number of this assembly? I want to try my luck at ebay (like one of the reply in your assembly video) to see if I can find a Carrier one. Thanks again.

[@grayfurnaceman]

@@R0N1NPANDA All that rod does is provide a gap for the spark and prove the pilot flame to shut off the spark. The pilot assembly has only 2 variants. The 2 wire and the 3 wire. You want the 3 wire. Do not buy a used one. You already have one of those. GFM

[@R0N1NPANDA]

@@grayfurnaceman I cleaned the orifice, and it seems the sparks can stop normally after pilot flame on. However, the intermittent furnace not on problem remains. Two questions, is LH680005 the correct model number for this? And i notice the replacement does not come with the "rod" (flame sensing thing above pilot), and the red rubber tube connecred to it. How do i remove it from the old assembly if i need to reuse? Thanks.

[@grayfurnaceman]

@@R0N1NPANDA I believe that is the right part for your furnace. There is a small screw on one side that clamps the spark rod to the pilot assembly. GFM

[@1995bisquick]

After all of the issues I've heard about these, I think I would prefer a standing pilot than this.

[@grayfurnaceman]

You are not alone. GFM

[@Resist4]

Initially my pilot light stays on but then goes out and won't stay lit, then the igniter keeps trying to light it over and over. The burners never light. Is the pilot assembly bad or is it the gas valve? It's at least a 35 year old two burner Payne furnace.

[@grayfurnaceman]

Does the unit have an inducer? GFM

[@Resist4]

@@grayfurnaceman if that’s a fan that runs when the furnace is turned on, prior to the pilot and burners lighting, then yes.

[@grayfurnaceman]

@@Resist4 You probably have a failing pilot switch. Very common failure. GFM

[@Resist4]

@@grayfurnaceman so if I remove the pilot assembly will there be a number on it so I can find a replacement or are all 3 wire pilot assemblies the same?

[@grayfurnaceman]

@@Resist4 If its a 3 wire, they are all the same. GFM

[@justdissin7340]

No way to test that assembly with ohms or resistance?

[@grayfurnaceman]

The test is the switch changing position when the pilot is lit. GFM

[@brownwater2488]

My problem is that I don't hear the clicking that tells me that the spark is actually trying to light up/ What am I doing wrong

[@grayfurnaceman]

+Andrickson Alix The most common problem is the 3 wire pilot has failed to return to normal position. Best to try replacement. GFM

[@brownwater2488]

Thanks for your fast response. After watching your video I realized that the turn on switch was far away from the heater itself. Now it's up and running. Some idiot decided to put it by the stairs

[@nuoljucovic4930]

You got a problem with the gas valve

[@jeffreycarter6473]

It's a high-voltage line that generates the spark...not a high-tension line...

[@TheLandlordPicker]

Hi, not sure if you still answer questions on older videos. I have watched your videos in the past (i am a landlord/do it yourselfer) and stumbled upon this one while trying to diagnose an old Bryant furnace. By the way thank you for the videos you have put out. yours and other people that help diagnose are doing a great service. My furnace has this same 3 wire pilot assembly and I think I may replace it. (although it is pricey at a few hundred dollars) The issue is that the furnace will light, then go out and re-light about 10 times, (and sometimes sparking like a baby rattle consistently) before finally staying on. Would you mind sharing an opinion on weather you think this pilot burner assembly would be the problem? Bryant 394GAZ036100 Thanks

[@grayfurnaceman]

Pretty good chance the pilot is failing. GFM

[@TheLandlordPicker]

grayfurnaceman thanks so much👍

[@TheLandlordPicker]

Hi, I just wanted to do a follow up on your advice to replace the 3 wire pilot assembly. I’d like to show you the problem that is having after replacement. It is acting better and lighting more often with the new part but there seems to be an added issue. Igniter will sometimes try to light continuously and then when I wiggle/flick or turn the blue pilot handle on the gas valve back-and-forth the pilot will light and stay lit. Which to me seems like maybe the gas valve needs to be changed. I believe the furnace to be over 20 years old. Definitely time for something upgraded but if it’s the gas valve that would definitely be the lower cost to repair. (As a landlord trying to stretch my dollar) And I do appreciate the videos and advice. Thx

[@grayfurnaceman]

First, more like 30 + years old. Are you saying the pilot does light with the spark but the spark continues, or does it not light? GFM

[@TheLandlordPicker]

grayfurnaceman hey thanks for getting back. Appreciate it. I actually did a video earlier today. Would love to have your insight. It actually started working a bit better before i left the rental earlier. But I’m sure its going to act up again. Here’s the link. kzbin.info/www/bejne/mWOrdaOqrMtkmK8

[@geojor]

good vid...

[@baylifehvac991]

Look at this all these DIY people on here , gray furnace man I like your videos, but people who have no idea of what they are doing are working on furnaces now because of your videos . I work hard and study a lot to learn this trade to make a decent living, but stuff like this will hurt us in the long run. Go somewhere and enjoy your retirement buddy .