blower won't come on

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  #1  
Old 12-19-07, 01:04 PM
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blower won't come on

We live in TX. House is about 13 yrs old and gas furnace (Carrier) is about the same. Just replaced blower this past spring (when AC wouldn't come on). Tried to turn on heat this winter and no blower. Had a guy diagnose -- he said it was the control board. I replaced the control board this morning. Blower comes on when AC is turned on, but not when heat is turned on. Ignitor works (good strong flames), but after burning for a bit, and no blower, it all cuts out.

Flashing code (nice to have on the new control board) is 33. I don't think we have filter/duct problems, nor do I think there are blower problems (since we just replaced it and it works with AC). Does that leave the flame roll-out switch? Do I just replace it?

Thanks for help!!
 
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  #2  
Old 12-19-07, 04:52 PM
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You could easily jumper the flame roll out device.

But I doubt this is your problem. You said the flame burns for a while before shutting down. How long does the burner flames last for before shutting down?
If it lasts long enough, there are certain problems we can rule out, because I would know then that the blower should at least be able to eventually come on.
 
  #3  
Old 12-19-07, 05:23 PM
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When I'm sitting there watching, waiting for the blower to come on, it seems like the flames burn for a loooong time before everything finally shuts off. Realistically, it's probably only a minute or so -- but by that I mean a full 60 seconds. I haven't actually timed it, but that's my guess.

Thanks for your help!
 
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Old 12-19-07, 06:16 PM
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That's close enough, for me to rush to judgement.

That means that if you were to run the furnace for 3 consecutive times in a row to where each time you got 1 minute of burner flame each time, and the blower still did not come on (conduct this test when you get the chance and report back) - that you have something electrically open in the fan circuit that is not allowing this. It is just a matter of tracing back to find where you are losing 120 volts going to the blower.

I am assuming your blower motor and bearings are stilll good as you replaced blower motor 3/4 year ago did you say? Direct drive motor? Have you tried to spin squirrel cage for the fun of it either when furnace is turned off to check bearings, or when you are running the furnace to see if spinning gets it going? Assuming there is no hum?

If furnace is limiting out, the blower should actually come on and try to cool it down. Just the flame should be shutting down if there still is a call for heat and it limits.

Trace wiring back to fan control to see if you have or lose power there, and move on from there with tracing back wires if need be.
 
  #5  
Old 12-19-07, 07:25 PM
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The blower comes on just fine when I switch to AC instead of heat. And I've spun the squirrel cage -- seems to spin just fine. (Haven't tried to spin-start it, though.) The blower motor was just replaced in June -- about six months ago.

Knowing that the blower comes on with AC, do you still think it's a power problem?

And what do you mean by "trace wiring back to fan control"? I'm new to this furnace game...all I've ever done is replace the blower motor and now the control board.
 
  #6  
Old 12-19-07, 07:41 PM
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I won't have a chance to do anything more until Saturday morning. I'll try spin-starting the blower, and I'll try your 3-times-in-a-row test, and I'll try checking wires, etc. Then I'll report the results. If you could check back here on Saturday, to help me out, that would be great. Thanks!
 
  #7  
Old 12-19-07, 09:28 PM
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Can you post the model # of the furnace? What is the part # of the new board?
 
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Old 12-20-07, 08:12 AM
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Originally Posted by profsteed View Post
The blower comes on just fine when I switch to AC instead of heat. And I've spun the squirrel cage -- seems to spin just fine. (Haven't tried to spin-start it, though.) The blower motor was just replaced in June -- about six months ago.

Knowing that the blower comes on with AC, do you still think it's a power problem?

And what do you mean by "trace wiring back to fan control"? I'm new to this furnace game...all I've ever done is replace the blower motor and now the control board.
ForGET what your blower does on a/c. Different circuitry is used for the heat making it come on. For one thing, it could very well be that the heat signal sends juice through different motor windings (via one of those other color wires going to the motor) to make the motor speed run slower for heat, than for a/c.

When I said about you running the furnace 3 times to have there be flame for 3 times in row, what happens is you end up building up heat in the heat exchanger. If the blower does not even come on then, after these 3 times, you definitely have an issue that something electrically is "open" when it should be electrically "closed" (connected to allow power through).

Now I am not sure if you have a fan timer or if your blower comes on by temp. But either way, with that test, if it does not come on by then, you have an open circuit in the heating circuit, not the a/c circuit.

By "trace the wires back", I mean you would see what color wires are on your blower motor. You may have from 3-7 wires. Forget the green, white and browns. Trace back black, red, yellow? and see where they go. Into the control board? Then test where this jucntion (plug in) is to see if you have 120 volts there right after those 3 back to back to back furnace run tests. You should have the circuit "closed" there, by then, to send 120 volt power to the blower. IF the wires plug into the main brainbox computer control board, then the timer switch may be bad in the board, if you do not have power coming out of it heading down one of those colored motor wires I mentioned. But if yo DO have 120 volts heading down there, then perhaps the windings in the motor for the heat circuit are bad.

But let us know where those say black, red and yellow? motor wires go after they leave the blower motor.
 
  #9  
Old 12-22-07, 11:27 AM
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Originally Posted by daddyjohn View Post
Can you post the model # of the furnace? What is the part # of the new board?
The number on the board is CES0110057-02

The model # is 58ZAV070-12
The product # is 58ZAV707-11112

There are black,red, and white wires coming from the blower to the control board. They plug into the back part of the board -- the red connects where it says "low," the black where it says "high," and I can't remember now what it says where the white connects.

I can't do the three-times-in-a-row test, because after the first time, when the burners kick off, the furnace will not come back on again. I've tried flicking the power switch on/off to reset, but I cannot get the furnace to come on again unless I wait for quite a while, first. So there doesn't seem to be any way to do the 3-times test.

Also, I tried spin-starting the blower, and that doesn't work. It won't start up, even after I spin it.

Finally, I tried checking the power at the board, but I guess I don't really know what I'm doing there. I have one of those outlet testers, but I can't seem to get the light to come on, no matter what I'm touching it to.

Help!?!
 
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Old 12-22-07, 02:24 PM
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Originally Posted by profsteed View Post
The number on the board is CES0110057-02

The model # is 58ZAV070-12
The product # is 58ZAV707-11112

There are black,red, and white wires coming from the blower to the control board. They plug into the back part of the board -- the red connects where it says "low," the black where it says "high," and I can't remember now what it says where the white connects.
Great. Now if you can volmeter test, when you DO get the flame to come on, and during anytime of it's burning, at least the red or black wire should have 120 volts coming out of the control module where they plug in, to head to the blower motor. Test and see if that happens.

I can't do the three-times-in-a-row test, because after the first time, when the burners kick off, the furnace will not come back on again. I've tried flicking the power switch on/off to reset, but I cannot get the furnace to come on again unless I wait for quite a while, first. So there doesn't seem to be any way to do the 3-times test.
This makes perfect sense if the blower motor is not coming on when it should, as then the furnace is likely limiting out. It takes time for the furnace to cool enough to UNlimit.

Also, I tried spin-starting the blower, and that doesn't work. It won't start up, even after I spin it.
Well it isn't going to go anyway, until the furnace has cooled down. If you know it is cool and you run the furnace and you don't even hear a hum, I have a feeling you have a problem with the motor or in the control module. You need to do that first test I mentioned.

If all was well with the motor or control module, the blower should run in the event of it limiting out (to cool off the heat exchanger), under normal circumstances where everything is working right.

Finally, I tried checking the power at the board, but I guess I don't really know what I'm doing there. I have one of those outlet testers, but I can't seem to get the light to come on, no matter what I'm touching it to.
You really need a multimeter (some call them voltmeters). You can buy a cheap one from $10-16 at home centers. Of even luck out and get one for only $3 on sale at one of the national chain tool stores (giving one to brother-in-law for stocking stuffer.).
 
  #11  
Old 12-22-07, 04:16 PM
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Problem solved. After more poking around, I discovered that the red wire coming from the board was plugged into the wrong slot -- next door to the slot where the red wire coming from the blower was plugged. (These slots are hard to see and hard to reach -- back behind everything -- which is why I didn't figure it out much sooner.) Once I got them aligned with each other, all was well.

Must have plugged it in the wrong slot when I installed the blower motor six months ago....

Thanks for your help!!
 
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Old 12-22-07, 04:30 PM
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At least we steered you to look at this area where it was joined.
 
  #13  
Old 12-27-07, 03:30 PM
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Wan

Hi, there,

I am a new member of this forum and not sure if this is the right place to post the question.

I was reading all correspondents regarding the Blower Not On in the hope that would give me some help. I guess I need more suggestions. Here is my problem.

While I was away from home, the house sitter turned thermo to 77 to 80 F degrees (our usual setting is 71 F degrees). At night she found the room temperature dropped to 56 F and the furnace flame was on less then 2 minutes and shut off because the blower was not on. Finally she called in a technician to check out next day. She was told no power from circuit board and that the circuit board was "burned out" and needed to be replaced. Since the tech did not have a board with him, in order to get heat, the tech wired blower motor directly. Now the blower is on continuously and the furnace operates with thermostat setting. According to the sitter, the tech spent about half an hour finishing the job. I had to pay the bill of $ 252.28

Before I go ahead to get the circuit board replaced as it will cost labour (1.5 to 2 hours) and part ($270 to 320) about another $500. I want to know it is the problem with the circuit board. Can someone advise me what to do to test on my own? My furnace is Carrier 58WAV091-14 and 10 years old. Thank you very much.
 
  #14  
Old 12-27-07, 03:54 PM
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Originally Posted by Wanchun View Post
Hi, there,

I am a new member of this forum and not sure if this is the right place to post the question.

I was reading all correspondents regarding the Blower Not On in the hope that would give me some help. I guess I need more suggestions. Here is my problem.

While I was away from home, the house sitter turned thermo to 77 to 80 F degrees (our usual setting is 71 F degrees). At night she found the room temperature dropped to 56 F and the furnace flame was on less then 2 minutes and shut off because the blower was not on. Finally she called in a technician to check out next day. She was told no power from circuit board and that the circuit board was "burned out" and needed to be replaced. Since the tech did not have a board with him, in order to get heat, the tech wired blower motor directly. Now the blower is on continuously and the furnace operates with thermostat setting. According to the sitter, the tech spent about half an hour finishing the job. I had to pay the bill of $ 252.28

Before I go ahead to get the circuit board replaced as it will cost labour (1.5 to 2 hours) and part ($270 to 320) about another $500. I want to know it is the problem with the circuit board. Can someone advise me what to do to test on my own? My furnace is Carrier 58WAV091-14 and 10 years old. Thank you very much.

In my years as a sefl employed furnace repairman, I gave a lot of thought as to what to look for when hiring any kind of service agency.

My cocnlusion is that the most important thing to look for was someone who was honest. The second most important thing was competence. You seem to have doubts about these issues with your service agency.


Generally speaking, most repairman tend to regard circuit boards as "black boxes." They are supposed to do certain things with certain inputs, and they either do or don't do them. If they don't replace them. Getting into issues of causality is usually not wirthwhile, since it's often not practical to test individual components on a circuit board.


Personally, nothing about the diagnosis seems unreasonable based on the facts you relate.

In order to double check the diagnosis you were given, you would have to understand the sequnce of operation of the furnace and the voltage inputs and outputs expected to and from the circuit board. There is probably a schematic diagram of the circuits on the furnace, but whether you can interpret them correctly only you can say.

Your prime opportunity to question the repairman about his diagnosis is while he was there. I always aimed to SHOW people defects whenever I could, so that they could understand my reasoning and have confidence in the recommendations I might make. Even if someone doesn't volunteer to do that, it's your opportunity to ask questions to satisfy yourself that you are getting good answers.

But since you weren't there, you missed that opportunity.


Unfortunately, a skilled repairman who has a mind to cheat you can probably do that pretty easily. You might decide that evasive replies or other behavior leaves you suspicious.


But as I said, nothing you relate strikes me as suspicious. It wounds like you are paying generous prices for service and parts, but not outrageous prices.

I'm can't recognize your particular furnace from the model number, but I'd expect to replace most circuit boards within an hour. Was the labor estimate you were given a flat rate (a flat charge for labor) or were charges going to be based on actual time it took to replace the part, with the 1.5-2 hours just a guess? Nothing wrong with gueessing liberally and presenting a customer with a smaller than expected bill.


In short, I see no reason to be suspicious that you are being treated unreasonably. There are things you can check if you have the skill. You can get estimates on replacing the part elsewhere if you wish. You can be present when the repairman shows up to replace the part and question him about his diagnosis then if you wish.
 
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Old 12-27-07, 05:03 PM
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Originally Posted by Wanchun View Post
I had to pay the bill of $ 252.28
What part of the country you live in and how far away you are from the shop enters in. Licensed ANYbodies charge more than people who are are just handy and work out of their home, obviously.

...and part ($270 to 320) about another $500.
I am guessing that is THEIR quote. I am certain the actual part can be had for way cheaper. For reasons like this, some people like to try to research and learn to do their own stuff and buy the stuff themselves. IMO, not too difficult a job unhooking wires and remounting a ($100-150? board).
 
  #16  
Old 12-27-07, 09:22 PM
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Wan

Hi, ecman 51 and seattlepioneer,

I live in Regina, Sask. Canada. There are a few Carrier's dealers in town that I had contacted for the information about replacing the circuit board. I was told it could take 1.5 to 2 hours to replace the board at a labour rate $63 to 75/hr. Charge will be based on the actual time spent.

Thank you for your prompt reply. I probably will get the board replaced by one of the dealers since I don't know any handy man myself.

if I have a replacement, would the circuit board be burn out again when the thermostat is set to 77 to 80 F degrees ?
 
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Old 12-27-07, 09:31 PM
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Originally Posted by Wanchun View Post
Hi, ecman 51 and seattlepioneer,

I live in Regina, Sask. Canada. There are a few Carrier's dealers in town that I had contacted for the information about replacing the circuit board. I was told it could take 1.5 to 2 hours to replace the board at a labour rate $63 to 75/hr. Charge will be based on the actual time spent.

Thank you for your prompt reply. I probably will get the board replaced by one of the dealers since I don't know any handy man myself.

if I have a replacement, would the circuit board be burn out again when the thermostat is set to 77 to 80 F degrees ?


As long as you are being charged only for the time used ---no problem. Giving a longer estimate than the time you actually might expect to use isn't unreasonable.

You might try shopping around for a better price on the circuit board, too. The price you got isn't outrageous, but it is a bit rich. As long as you are shopping on the phone, you are in a competetive market and the advantage is with you, especially since you know what needs to be done.


And I'd suggest you try to get the maintenance work on the furnace that might need to be done at the same time. Having that done every 2-3 years at a maximum is a good idea. Since you are having a repairman come out anyway, it ought to amount to an extra half hour of work or so, in most cases.


Good luck. I'd be glad to hear how your repair and maintenance works out for you.
 
  #18  
Old 12-28-07, 10:14 PM
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Wanchun

I had the circuit board replaced today at $ 399 plus tax. I phoned about 6 service agencies to compare the prices prior. The repairman spend about an hour to do the job. He could have done the maintenance if he did not have another appointment right after.

Thank you seattlepioneer. I am impressed about people from this forum how helpful you folks are.

By the way I tried to quote your message but did not have the success. I will try to figure it out.
 
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Old 12-29-07, 11:23 AM
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Did you watch him?
 
  #20  
Old 12-30-07, 09:51 PM
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The repair man was not the one who checked the furnace. upon his arrival, he asked me how I knew it was the circuit board problem. I told him about the situation. He said I had to take a look if it was the circuit board problem. I was there watching him. He said "yes, it's the problem with the board". He replaced the the board. It seemed easy for him to change the board. But it took a little while to connect the wires. He made a mistake with one wire as a result the fuse was burned out. He had to wait someone to deliver a new fuse. So it took him about an hour. Now the furnace is running OK.
 
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