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gotoman for ac
gotoman for ac, HVAC Technician
Category: HVAC
Satisfied Customers: 5119
Experience:  51 years of experience install design and repair of all makes and models of AC
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Hi, I have a ruud achiever 90 plus heating furnace. The

Customer Question

Hi,

I have a ruud achiever 90 plus heating furnace. The blower always runs without stop. I've took 4 lines off Thermostat. It still runs automatically. What I should do?
Submitted: 6 years ago.
Category: HVAC
Expert:  gotoman for ac replied 6 years ago.
I need model number of furnace and I will pull manual. Russ
Expert:  gotoman for ac replied 6 years ago.
Does furnace fire and heat?
Customer: replied 6 years ago.

I tried the thermostat to control temperature to get heat, it failed. I tried open the furnace rack and didn't see fire when blower was running.

Expert:  gotoman for ac replied 6 years ago.
Limit switch is stuck open or bad furnace board. If you want to check limit switch it is located just aboce burners. 3X3 ceramac plate with two wires coming out of them. Take loose and remove from furnace there will be a disc on the end of two prongs. Clean the disc by tapping it. Replace and retry furnace. Russ
Customer: replied 6 years ago.

I remember it caused by our area power failure a few days ago. When power supply was restored, I found my furnace blower run and stop repeatly. I switched the power off, and turned on after one day. it started the issue I presented. The doc said it looks like a limit control issue which is on the intergral control board. I am not sure if I should it is right.

 

Thanks you anwser, I am going to down to look at the limit switch.

Expert:  gotoman for ac replied 6 years ago.
Ok get back once you check it. Russ
Customer: replied 6 years ago.
Sorry, where is the limit switch? where is the burner? is it on circuit control board on down rack or i have to open upper rack to find them? Thanks
Expert:  gotoman for ac replied 6 years ago.
Take front off furnace and you will see a gas valve. square valve. Just above that you will see a ceramac plate about 3X3 with two wires coming off of it. Take the two wires off put them together and retry furnace. If everything works it is a bad limit switch. If not problem is in furnace board. Russ
Customer: replied 6 years ago.

Found it. I tried to connect two wires together. it still no stop for blower runing. There is no fire and heat also.

Expert:  gotoman for ac replied 6 years ago.
Did you connect the wires, Russ
Customer: replied 6 years ago.
yes. Russ. now it bypasses the limit switch. But same result as before.
Expert:  gotoman for ac replied 6 years ago.
Are your burners on bottom anf fan on top of furnace. If so there is another limot above furnace board. Russ
Customer: replied 6 years ago.
Burners is on top of furnace. Fan is on bottom. There is only one burner I found on the upper funace board.
Expert:  gotoman for ac replied 6 years ago.
My manual shows both furnaces upflow and downflow. Look at furnace board and check diagnostic lights. They will blink a code. Count flashes and look on blower door or blower housing for code. Let me know what the code says. Most of the time the fan running is open limit switch. The code will let us know. Russ
gotoman for ac and other HVAC Specialists are ready to help you
Expert:  gotoman for ac replied 6 years ago.
If you jumper limits do not leave jumpered. Russ
Customer: replied 6 years ago.
Ok. You mean separate two wires without jumper connection? leave them alone without any connections?
Expert:  gotoman for ac replied 6 years ago.
If you jumper any limit it is just to test limit to see if open. Leaving it jumpered furnace will not shut down if it overheats. Just being safe, Russ
Customer: replied 6 years ago.
don't worry, I have turn the power switch off. One thing I would you know that even it is jumped and blower is working, there is no fire and heat, so there is no worry for overheats.
Expert:  gotoman for ac replied 6 years ago.
Have you checked diagnostics on board. Russ
Customer: replied 6 years ago.
Not yet. What do you want me to find? If there is problem of board. Where can I get a replacement?
Expert:  gotoman for ac replied 6 years ago.
The diagnostics will tell you problem area. Such as limit switch,pressure switch and so on. It will get us in right area. Russ
Customer: replied 6 years ago.
There is a troubshooting flows on the back of front door. I haven't see "OK" LED and other leds flash during starting.
Expert:  gotoman for ac replied 6 years ago.
If there are no LEDs flashing check fuse on board if it is OK replace board. If you need to know where to purchase board get back with me. Russ
Customer: replied 6 years ago.

Hi Russ,

 

I will check the fuse when I back home. Let me know where I can get board and estimated cost. Thanks

Expert:  gotoman for ac replied 6 years ago.
Get back when you check fuse. Russ
Customer: replied 6 years ago.

Where is the fuse on board? How can I check it out? Do you think it is normal there is no flame in furnace? Or it is only trigged when it needs heating to work.

Expert:  gotoman for ac replied 6 years ago.
The sequence is thermostat calls for heating ..induce draft motor starts..20 seconds..igniter glows 5 seconds ...gas valve opens. Fuse is plugged into board 3 OR 5 Amp auto type purple or yellow. Russ
Customer: replied 6 years ago.
I found it. It looks good when I pulled it off and check with my Voltmeter. I am leaving in Devon PA 19333. Where can I purchase the board? Is it difficult to replace it?
Expert:  gotoman for ac replied 6 years ago.
Once more question do you see any lights on board. Russ
Customer: replied 6 years ago.
No. Only three LEDs are on when it is working
Expert:  gotoman for ac replied 6 years ago.
The board is not easy change the new boards have new revisions that and you have to adapt new one to fit. It would not cost anymore for a tech to change board than you can buy it. The new board online is about 300.00. I would get a quote from local service company first. Russ
Customer: replied 6 years ago.
Thanks your advise. Are you aware of our local service company or technician? I saw on RUUD website. this model seems to be 10y warranty. As I moved to this house two years. don't know which year this furnace was installed.
Expert:  gotoman for ac replied 6 years ago.

Get me serial number and I can give you year made. Russ

Customer: replied 6 years ago.

t150205755

 

rcba-4882GG21XI

Expert:  gotoman for ac replied 6 years ago.
Looks like 02 model. If you have a 10 year warranty. Still under warranty. Warranty has to be down by service tech. Any company can warranty your unit. Can not recommend anyone in area. Site violation. Sorry. Russ
Customer: replied 6 years ago.

Ok. I will contact local guys. Thanks your great help!

 

Best Regards

 

Yongxing

Customer: replied 6 years ago.

They came to look into. and sure the board is fail. But the replacement cost is very high. Let me know how to get a new board online. Thanks

 

Expert:  gotoman for ac replied 6 years ago.

www.americanhvacparts.com Part number C1B22408A Check your board and this one to make sure. They have a toll free number to call on site. Russ

Customer: replied 6 years ago.

Russ,

 

I input the Part number and get no matching products were found.

Expert:  gotoman for ac replied 6 years ago.
Part number CIB6224268 Double Check Model number in list below part. In ran part number it went thru. Russ

Edited by gotoman for ac on 10/9/2010 at 9:54 AM EST
Customer: replied 6 years ago.

Russ,

 

It looks not matching my part number I checked out on my furnace. See below

 

 

P/N G961DAJ-2403

PN 62-241360-03

 

The closed matching one online is G961DAJ-2402. Can I use that ? Thanks!

 

 

Expert:  gotoman for ac replied 6 years ago.

Check out number I gave this morning. It is cross for your furnace can not go by part number unless going direct to Rheem. Russ

Customer: replied 6 years ago.

Under your number, I couldn't find my Model RCBA-4882GG21. But any part numbers do not include this model.

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Expert:  gotoman for ac replied 6 years ago.
That is coil model nember not furnace. According to the site you gave me you have RGRA model. Russ
Customer: replied 6 years ago.
I found my model on inside of furnace. it is UGRA-07EYBGS. but it seems still not covered.
Expert:  gotoman for ac replied 6 years ago.
www.americanhvacparts.com CIB622408A. Is your board. Russ
Customer: replied 6 years ago.

Great! CIB622408A is matching UGRA-07EMAS. Is it ok as mine is UGRA-07EYBGS? What have to be tuned on this new board if there is difference? Thanks alot!

Expert:  gotoman for ac replied 6 years ago.
It will go right back in . No problem. Just mark wires. Russ
Customer: replied 6 years ago.

Russ,

 

I called HVACparts.com. She checked my furnace model and serial number. gave me a model below.

 

Code: CIB6224140. And confirmed this is matching my furnace. There is no return policy. But there is 90 days warannty. Just confirm with you if I should process the purchase. Thanks

Expert:  gotoman for ac replied 6 years ago.

Yes . Just make sure you mark wires and turn off power before installing new board. Are you saving any money by doing this yourself. Russ

Customer: replied 6 years ago.
I've paid local company onsite looking into. They should be able to come to replace board for me. Question is if it doesn't work, local company will not take any responsibility. What I can do then.
Expert:  gotoman for ac replied 6 years ago.
If you have gave parts company correct furnace model number and serial number . It will work OK. Before you order just double check number. Russ
Customer: replied 6 years ago.

Hi Russ,

 

I got the new board. Not sure if following patching will be matchimg from old to new:

 

24 VAC line -> SEC

24 COM line ->COM

Line Neutral three lines -> same three lines. But no specific indication for each line naming. If I do lines switched among them, is it bad thing will happen

 

Between HUM and EAC indication there are two lines patched -> only two lines with indication L1 upper and XFMR-PRI downside.

 

F, H, C three lines -> Fan, Heat, Cool three line

 

M2 -> M2

 

 

 

 

 

Expert:  gotoman for ac replied 6 years ago.
M2 or the M terminals is where you put the speed wires for fan that are not used. Neutrl terminals does not matter on wire as long as they are neutral. Fan is continuous fan. Red to Heat and Black to cool. L1 to L1. Russ
Customer: replied 6 years ago.

On old board, there is a line terminated on M2. May I move to new board M2? Two lines terminated on L1. Does it matter if they are switched on new board L1? What L1 lines used for? Thanks Russ. It is so nice to get your message again.

 

Regards

 

Yongxing

Expert:  gotoman for ac replied 6 years ago.
M2 is a place for speed on motor not used. L1 is power to unit. Russ
Customer: replied 6 years ago.

What 24 VAC and 24 COM terminals on old board are used ? And on new board same position, there are SEC and COM terminals. What is that for? Are they the same?

 

 

So L1 is 110V power supply? Is there positive and negitive has to be careful?

 

Thanks

Expert:  gotoman for ac replied 6 years ago.
That is AC voltage no - or + to worry about. Russ
Customer: replied 6 years ago.

connected all the lines. nothing was running when I pressed door button. I tried to measure the voltage between two L1 lines. I didn't see any AC value. Is it my power supply issue?

Expert:  gotoman for ac replied 6 years ago.
Measure L1 to Neutral see what you have. Russ
Customer: replied 6 years ago.

I measured each L1 line to Neutral. Nothing was seen. voltage needle did not move.

Expert:  gotoman for ac replied 6 years ago.
Did you have door switch pushed in when you measured voltage. Russ
Customer: replied 6 years ago.
yes. Sir.
Expert:  gotoman for ac replied 6 years ago.
OK. Check power at plug or switch to furnace. You should have power on L1 to neutral. You can also check L1 to ground or any metal on the furnace. Russ
Customer: replied 6 years ago.
I reset power switch. It works now. I see flame and blower working, But I need check every others. Thanks
Expert:  gotoman for ac replied 6 years ago.
No problem. Great work on your part. I am impressed. Russ
Customer: replied 6 years ago.

Heating is working under the Thermostat control. It seems taking a longer while to start flame when I set the temperature up. But it should be not big issue. It is awesome. I feel like to get a big success. Without your expertise and kinds of guide, this would not happen. It is really appreciated for your valuable assistance. I believe every customer got or will get the same feeling like me. I will refere to other around guys if their house furnace happens to have any issue like me. It is a very good experience of my DIY.

 

Thank you very much. Russ

 

Yongxing

Expert:  gotoman for ac replied 6 years ago.
You are welcome.Great job. Russ