Posts belonging to Category 'Comfortmaker Furnace Parts'

AC Repair: Burned-out contactor

Question:

Over the Labor Day weekend, my AC unit went out. After pulling off the cover, I saw that the contactor had burned out. As our temperatures have been consistently in the high 90’s, I’ve noticed the unit seemingly constantly in the "Compressor ON" mode. Although the wife and kids had to suffer a couple of days of miserable heat, I’ve replaced the contactor, but am wondering what is the cause as down south, we live with 90+ temp all the time. I had installed a contactor earlier this season as the original unit blew out early in the summer. Although the price of a contactor is cheap compared to buying a new unit, I often figure something else is involved when I have to repair the same AC part within a single season. My unit is a ComfortMaker (snyder general) and is rapidly approaching 16 years of age. Am I simply watching a unit about to sing its swan song, or should I be replacing all the electrical parts that control the compressor (capacitor and some other big piece with the 240v wires and a power resistor)? ToRo

Response:

– Hide quoted text — Show quoted text – Over the Labor Day weekend, my AC unit went out. After pulling off the cover, I saw that the contactor had burned out. As our temperatures have been consistently in the high 90’s, I’ve noticed the unit seemingly constantly in the "Compressor ON" mode. Although the wife and kids had to suffer a couple of days of miserable heat, I’ve replaced the contactor, but am wondering what is the cause as down south, we live with 90+ temp all the time. I had installed a contactor earlier this season as the original unit blew out early in the summer. Although the price of a contactor is cheap compared to buying a new unit, I often figure something else is involved when I have to repair the same AC part within a single season. My unit is a ComfortMaker (snyder general) and is rapidly approaching 16 years of age. Am I simply watching a unit about to sing its swan song, or should I be replacing all the electrical parts that control the compressor (capacitor and some other big piece with the 240v wires and a power resistor)? ToRo

I don’t work on AC units but I can pass on what I see on irrigation systems. It’s not unheard of to get a new contactor that isn’t any good. I’ve had brand new ones not work. That’s very rare but it can happen. Did the replacement part have a cover over the contacts to keep bugs and dirt out? Moths are attracted to the flash when contacts open and close. I’ve seen contactors placed inside of tupperware containers to keep bugs and dirt out. Put a couple small holes on the bottom side of the container to drain condensation. I’ve seen bad motors ruin contactors. That only happened after the motor had a dead short in it. I had to replace the contactor after replacing the bad motor. Have you checked the voltage to the contactor coil and contacts? Low voltage is murder on the contacts. I’d suggest checking all the wiring including the control circuits. Possibly the contacts aren’t being held in tightly due to a bad connection somewhere. I wonder if a bad thermostat is a possibility. A contactor that chatters when closing doesn’t last long. You might be able to put in a contactor with a higher contact rating. Irrigation systems use contactors with a much higher contact rating than dictated by the motor horsepower. These contacts open and close very often and the higher rating gives longer life. Good luck, Dean

Response:

- Hide quoted text — Show quoted text – Over the Labor Day weekend, my AC unit went out. After pulling off the cover, I saw that the contactor had burned out. As our temperatures have been consistently in the high 90’s, I’ve noticed the unit seemingly constantly in the "Compressor ON" mode. Although the wife and kids had to suffer a couple of days of miserable heat, I’ve replaced the contactor, but am wondering what is the cause as down south, we live with 90+ temp all the time. I had installed a contactor earlier this season as the original unit blew out early in the summer. Although the price of a contactor is cheap compared to buying a new unit, I often figure something else is involved when I have to repair the same AC part within a single season. My unit is a ComfortMaker (snyder general) and is rapidly approaching 16 years of age. Am I simply watching a unit about to sing its swan song, or should I be replacing all the electrical parts that control the compressor (capacitor and some other big piece with the 240v wires and a power resistor)? ToRo

i guess you talking about the relay… had one go out on mine on a sunday evening and no way of getting parts….. took it apart and found a small "rain spider" fried to s crisp between the contacts… i was lucky this realy was an old general type that you could take off the points and just flip them over and use the other side as it had contacts on both sides… it lasted about another 10 yrs… the bugs like to go into these area, also with replacing it in a short time period,, remember that all the stuff that’s made in china now days…. some of it is junk and was made using poor testing and quality control…

Response:

Well, Dean So far so good, the contactor is keeping me cool. I’ll have to run some checks on those voltages, but honestly, now that it is cooling, I’m afraid to F*?k it up. At least you’re recommending that I change AC units….yet:) ToRo – Hide quoted text — Show quoted text – Over the Labor Day weekend, my AC unit went out. After pulling off the cover, I saw that the contactor had burned out. As our temperatures have been consistently in the high 90’s, I’ve noticed the unit seemingly constantly in the "Compressor ON" mode. Although the wife and kids had to suffer a couple of days of miserable heat, I’ve replaced the contactor, but am wondering what is the cause as down south, we live with 90+ temp all the time. I had installed a contactor earlier this season as the original unit blew out early in the summer. Although the price of a contactor is cheap compared to buying a new unit, I often figure something else is involved when I have to repair the same AC part within a single season. My unit is a ComfortMaker (snyder general) and is rapidly approaching 16 years of age. Am I simply watching a unit about to sing its swan song, or should I be replacing all the electrical parts that control the compressor (capacitor and some other big piece with the 240v wires and a power resistor)? ToRo I don’t work on AC units but I can pass on what I see on irrigation systems. It’s not unheard of to get a new contactor that isn’t any good. I’ve had brand new ones not work. That’s very rare but it can happen. Did the replacement part have a cover over the contacts to keep bugs and dirt out? Moths are attracted to the flash when contacts open and close. I’ve seen contactors placed inside of tupperware containers to keep bugs and dirt out. Put a couple small holes on the bottom side of the container to drain condensation. I’ve seen bad motors ruin contactors. That only happened after the motor had a dead short in it. I had to replace the contactor after replacing the bad motor. Have you checked the voltage to the contactor coil and contacts? Low voltage is murder on the contacts. I’d suggest checking all the wiring including the control circuits. Possibly the contacts aren’t being held in tightly due to a bad connection somewhere. I wonder if a bad thermostat is a possibility. A contactor that chatters when closing doesn’t last long. You might be able to put in a contactor with a higher contact rating. Irrigation systems use contactors with a much higher contact rating than dictated by the motor horsepower. These contacts open and close very often and the higher rating gives longer life. Good luck, Dean

Response:

Thanks Jim for your insights. You may be right about the bugs, there were spider webs and dirt in the area. But for now I cool, but maybe someone will chime in and tell me what preventative maintenance I can perform to make this unit last a few more years. ToRo – Hide quoted text — Show quoted text – Over the Labor Day weekend, my AC unit went out. After pulling off the cover, I saw that the contactor had burned out. As our temperatures have been consistently in the high 90’s, I’ve noticed the unit seemingly constantly in the "Compressor ON" mode. Although the wife and kids had to suffer a couple of days of miserable heat, I’ve replaced the contactor, but am wondering what is the cause as down south, we live with 90+ temp all the time. I had installed a contactor earlier this season as the original unit blew out early in the summer. Although the price of a contactor is cheap compared to buying a new unit, I often figure something else is involved when I have to repair the same AC part within a single season. My unit is a ComfortMaker (snyder general) and is rapidly approaching 16 years of age. Am I simply watching a unit about to sing its swan song, or should I be replacing all the electrical parts that control the compressor (capacitor and some other big piece with the 240v wires and a power resistor)? ToRo i guess you talking about the relay… had one go out on mine on a sunday evening and no way of getting parts….. took it apart and found a small "rain spider" fried to s crisp between the contacts… i was lucky this realy was an old general type that you could take off the points and just flip them over and use the other side as it had contacts on both sides… it lasted about another 10 yrs… the bugs like to go into these area, also with replacing it in a short time period,, remember that all the stuff that’s made in china now days…. some of it is junk and was made using poor testing and quality control…

Response:

CBHVAC, Might I make in the nicest possible way, after reading your post, a suggestion? Call someone that knows what he is doing….and have the unit checked. I just replaced, a transformer, a contactor, a capacitor, and thermostat due to someone this weekend attempting a repair like this… A $12 part ended up costing him over $300.

Good suggestion – that’s how I learned how to replace the contactor. The early season replacement/repair was done by a local hvac guy who claimed that was my only problem. When the ac stopped cooling over the weekend, I repeated his steps for removing the cover and saw that the same piece he replaced, i.e., the contactor/relay, had "fried". Since I knew the part, saw that it was connected to just a few wires and held on by two screws, I tackled it myself and saved by avoiding a $185 service call to install a $31 part. My intent was to possibly identify what is causing the contactor to blow. Since you listed any number of factors: Compressor overamping age bugs wrong rating surge. I can only assume that there is no one single answer, especially since the hvac guy simply did a remove and replace the first time. Maybe there is no real diagnosis, just fix it when it breaks. Are there any symptoms that may be helpful in such a diagnosis? I have noticed that the compressor seems to delay in kicking on when the inside unit starts up. I seem to recall that in years past, as soon as the inside starts blowing the compressor would be on. Now there can be a maybe two minute delay. Perhaps, the capacitor or transformer you mentioned is getting "long in the tooth"? Should I replace these parts? ToRo

Response:

Contactors burn up due to several reasons… Compressor overamping age bugs wrong rating surge. Might I make in the nicest possible way, after reading your post, a suggestion? Call someone that knows what he is doing….and have the unit checked. I just replaced, a transformer, a contactor, a capacitor, and thermostat due to someone this weekend attempting a repair like this… A $12 part ended up costing him over $300.