MiCarl Posted March 2, 2015 Author Share #26 Posted March 2, 2015 Mine went out again. I wonder what the technical reason is that they fail at bed time instead of while the sun is out........ Manually lit it last night and had to light it again this morning, so it hasn't "healed" itself this time. At least it's not so bitterly cold. New ignition control is on order. Link to comment Share on other sites More sharing options...
uncledj Posted March 3, 2015 Share #27 Posted March 3, 2015 Good luck,....let us know how it goes. Link to comment Share on other sites More sharing options...
MiCarl Posted March 3, 2015 Author Share #28 Posted March 3, 2015 For the time being it's started working again. That ignition control box is deep enough I bet it has relays in it - probably have a contact that is worn out. At some point in the future I may look into trying to repair it, the "universal replacement" I have on clearly is not as weather resistant as the original. Also, it finally occurred to me that that access panel probably had a schematic on back. I took a look and it sure does. Now I know which wire does what. It should only take a few minutes to drop in the replacement. Link to comment Share on other sites More sharing options...
tlm Posted March 3, 2015 Share #29 Posted March 3, 2015 Good luck. Link to comment Share on other sites More sharing options...
ragtop69gs Posted March 5, 2015 Share #30 Posted March 5, 2015 Carl, Lucky you,,, I just found that I have a cracked heat exchanger on my furnace Good thing is I have a split system so half the house is still warm. I guess I can't really complain though, it's been there since 1983 and other than annual maintenance I've only had to replace the thermo-couple twice. That Carrier has served me well. R.I.P. I'll now move into the world of 90%+ furnaces. Link to comment Share on other sites More sharing options...
MiCarl Posted March 5, 2015 Author Share #31 Posted March 5, 2015 Carl, Lucky you,,, I just found that I have a cracked heat exchanger on my furnace Good thing is I have a split system so half the house is still warm. I guess I can't really complain though, it's been there since 1983 and other than annual maintenance I've only had to replace the thermo-couple twice. That Carrier has served me well. R.I.P. I'll now move into the world of 90%+ furnaces. Ouch! That's going to be a bit more than my ignition control. Link to comment Share on other sites More sharing options...
ragtop69gs Posted March 5, 2015 Share #32 Posted March 5, 2015 Ouch! That's going to be a bit more than my ignition control. Ya think AH the joys of home ownership Link to comment Share on other sites More sharing options...
MiCarl Posted March 5, 2015 Author Share #33 Posted March 5, 2015 The plot thickens...... The new ignition control came in. It's status indicator shows low voltage when the pilot valve is connected. The meter I have here has short leads and no alligator clips so it was tough to get a good reading but it looks like about 1V at the ignition control. I get 30V at the transformer with the ignition control connected. I bypassed a bunch of stuff without resolving the problem before I got cold enough to give up and re-connect the original control. The new control gets all it's power from the thermostat wire, where the original has an extra lead directly to the transformer for power. The original also seems to ground through the chassis in addition to the ground lead. I'm starting to think maybe my whole problem is low voltage on the thermostat wire at the control (I did bypass the thermostat with no improvement in voltage). I'll bring my good meter and test leads home from the shop and try again on a warmer day..... Link to comment Share on other sites More sharing options...
ragtop69gs Posted March 5, 2015 Share #34 Posted March 5, 2015 Sorry to hear of your continued problems, wanna trade? Link to comment Share on other sites More sharing options...
MiCarl Posted March 5, 2015 Author Share #35 Posted March 5, 2015 Sorry to hear of your continued problems, wanna trade? I was thinking about offering you a deal on a heat exchanger...... Link to comment Share on other sites More sharing options...
tlm Posted March 6, 2015 Share #36 Posted March 6, 2015 ragtop68gs, those heat exchangers are probably still available. If they are what I think they are. But it would be cheaper in the long run to replace the furnace. Link to comment Share on other sites More sharing options...
ragtop69gs Posted March 6, 2015 Share #37 Posted March 6, 2015 Being it's a 1983 furnace I'll just replace it. Link to comment Share on other sites More sharing options...
tlm Posted March 6, 2015 Share #38 Posted March 6, 2015 It would be better to do that. Link to comment Share on other sites More sharing options...
Leland Posted March 6, 2015 Share #39 Posted March 6, 2015 The plot thickens...... The new ignition control came in. It's status indicator shows low voltage when the pilot valve is connected. The meter I have here has short leads and no alligator clips so it was tough to get a good reading but it looks like about 1V at the ignition control. I get 30V at the transformer with the ignition control connected. I bypassed a bunch of stuff without resolving the problem before I got cold enough to give up and re-connect the original control. The new control gets all it's power from the thermostat wire, where the original has an extra lead directly to the transformer for power. The original also seems to ground through the chassis in addition to the ground lead. I'm starting to think maybe my whole problem is low voltage on the thermostat wire at the control (I did bypass the thermostat with no improvement in voltage). I'll bring my good meter and test leads home from the shop and try again on a warmer day..... What model is your new control? You say that you have 30V at the transformer with the ignition control connected, but did you check power at the t-former while it was trying to light? A bad t-former can act just like a bad battery. Show proper voltage with no load, but loose voltage under load, which is the greatest while trying to light. Replacement t-former must be rated for sufficient VA (volts X amps) to supply power to 24V components. Typically a minimum of 40VA. Link to comment Share on other sites More sharing options...
MiCarl Posted March 7, 2015 Author Share #40 Posted March 7, 2015 What model is your new control? You say that you have 30V at the transformer with the ignition control connected, but did you check power at the t-former while it was trying to light? A bad t-former can act just like a bad battery. Show proper voltage with no load, but loose voltage under load, which is the greatest while trying to light. Replacement t-former must be rated for sufficient VA (volts X amps) to supply power to 24V components. Typically a minimum of 40VA. The new control draws its power from the thermostat wire. When the thermostat first calls for heat the spark fires but the pilot valve doesn't open. After it finishes sparking the low voltage indicator comes on. At that point I measure less than 2V at the control but 30V at the transformer. If I disconnect the pilot valve I get the spark and no low voltage indicator, and measure 30V at the control. So I've got about 28V voltage drop on the circuit with the gas valve load. The original Johnson Controls G60 has a separate power lead (in addition to the thermostat) that I believe powers the gas valves and maybe the spark. It also grounds through the chassis in addition to the ground lead back to the transformer. The G60 has been working fine since Monday morning. I brought my better meeter with long leads and alligator clips home from work today. With the warmer temps this weekend I'll chase down my voltage drop. I'll also check to see if the G60 is pulling the voltage from the thermostat low, if so that might be the cause of my original problem. Link to comment Share on other sites More sharing options...
Leland Posted March 7, 2015 Share #41 Posted March 7, 2015 Easy test: Remove thermostat from its' subbase and jumper the two wires in the subbase. If it works, then maybe just a bad thermostat. If above proves true, this temporary fix may get you through the winter. Add 24VAC coil relay. Wire N.O. contacts of relay to thermostat terminals on ignition control. Wire one relay coil terminal to one side of 24V transformer. Wire other transformer terminal to one of the thermostat wires. Second thermostat wire to other coil terminal. This will take all of the load off of the thermostat. Link to comment Share on other sites More sharing options...
MiCarl Posted March 7, 2015 Author Share #42 Posted March 7, 2015 I already jumpered around the thermostat and its wiring. I narrowed the problem down to a couple connections inside the furnace before I got cold and quit (remember, it's outside and I need to lay in the snow to work on it). Link to comment Share on other sites More sharing options...
Flyinfool Posted March 7, 2015 Share #43 Posted March 7, 2015 So you are saying that you need more snow to bury the problem to make it go away? Link to comment Share on other sites More sharing options...
WildBill1 Posted March 8, 2015 Share #44 Posted March 8, 2015 My Carrier has a float switch on the condinsate line. At extreme cold temps line freezes gas shuts off initor doesn't Fire dead in water so to speak. Link to comment Share on other sites More sharing options...
MiCarl Posted March 8, 2015 Author Share #45 Posted March 8, 2015 For those of you eagerly watching for the next installment. Went back at it today with the meeter with longer leads and alligator clips. I'm reading 29V at the new ignition control while it is showing low voltage. The brand new ignition control is bad. Link to comment Share on other sites More sharing options...
uncledj Posted March 8, 2015 Share #46 Posted March 8, 2015 Been up to the cabin and without internet since Thursday afternoon. I'd like to see you put 24v directly to the pilot valve to see if it opens, (momentary test) It's possible that the pilot valve has failed in such a way that it's drawing high amperage when power is applied. Another thing to consider is that, while I don't know that it'd be a problem, 29v is a bit high. Many electronic controls start to get flaky above 28, ...or at least that's what I'm told is the danger point for most energy management equipment. I'm back to the world of phone and internet service, so call if you need to. Link to comment Share on other sites More sharing options...
MiCarl Posted February 6, 2016 Author Share #47 Posted February 6, 2016 An update: In the process of trying to correct the low voltage fault at the replacement control I cleaned up all the connections. Still the control complained of low voltage -> I believe it was doing that with the gas valves disconnected so it was only the spark drawing power. After discussions with the manufacturer we decided the control was bad and I started the exchange process. All while waiting for the exchange the furnace continued to operate properly. When the replacement control arrived I decided to wait until it crapped out again or spring to put the new control on. It worked fine until spring and I put the replacement control on. THE REPLACEMENT CONTROL FAULTED OUT WITH A LOW VOLTAGE STATUS! I decided the controls I'm buying are junk (it was under $100) and just put it on a shelf figuring if the furnace worked that long I was set. This week the furnace crapped out again. Lit it manually a couple times and it's been fine since. I decided to throw a new transformer at it. The original was 40VA but a humidifier has been added, so I decided to go BIG. I drove 40 miles round trip to pick up a 75VA transformer. The new transformer was only doing 15V with no load connected. Another 40 mile trip and I've got one that shows 27V (my line voltage is 246). So far it hasn't acted up, but it might take another year before it fails again anyhow. Link to comment Share on other sites More sharing options...
uncledj Posted February 6, 2016 Share #48 Posted February 6, 2016 Are you sure you're not having a line voltage power problem? Something fishy there. Heading out the door now, but I'll take another look at the info for that control. I think that if it's not too much trouble it may be worth putting in a newer style controller. I should have parts laying around that you can have to do it. Transformers generally don't have low output unless there's a low input. They also generally don't fail unless they're grossly overloaded to the point where they heat up and eventually short out. Link to comment Share on other sites More sharing options...
MiCarl Posted February 6, 2016 Author Share #49 Posted February 6, 2016 (edited) Thanks for the offer, but I still have the new control that was complaining about low voltage from the old transformer. Besides, if you send me parts your furnace will probably need them tomorrow. The first replacement transformer was definitely bad. After I pulled it off the furnace I tested it on the bench - with 146V at the primary I was only getting 15V on the secondary. I'm not sure how much line voltage variation is normal. It's possible my HF multi-meter reads high. I have a fancy power conditioner on the home theater with a voltage meter that currently reads 126V. That with 120 on the other leg would give me the 246 I see at the furnace and in the garage. Everything else we own seems to work just fine. I'm skeptical the transformer was the problem but they're inexpensive and easy to replace so I thought I'd cover that base. If it acts up again I'll see how the new control likes the new transformer. Edited February 6, 2016 by MiCarl Link to comment Share on other sites More sharing options...
uncledj Posted February 7, 2016 Share #50 Posted February 7, 2016 Just got home. Okie dokie, I won't worry about it until I hear otherwise from you. For what it's worth, I literally have buckets and boxes of controls, transformers, contactors, relays, temp / pressure switches and the like. Lately I've been thinking about giving the stuff away to make room, so don't worry about me needing something after I get rid of it.....I'd be sure to have a few more lying around somewhere. Anyhoo, best of luck. I wish you lived a bit closer....a modification / upgrade shouldn't be a big deal for someone familiar with this stuff. Link to comment Share on other sites More sharing options...
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