AO Error - Now what!

[ffabcd4]

Hi all,

Okay, let's start by saying no electrical knowledge Hayward 250fdn heater AO Error. Just clicking when turning on, nothing else. Then just sits for a bit then goes to AO Error.

Following attached picture flow chart:

Is blower damaged? What does damaged mean, looks fine to me, nothing out of the ordinary, so NO.
Blower Vacuum switch wires 'look' fine to me, nothing that sticks out, so NO.
Vacuum tube- Don't see anything wrong with but did try replacing it just in case, same result, so I assume it's fine, so NO.
Voltage plug - I assume it should be 120?, if so that is correct.
Blower Ohms - Tested the Ohms on the blower (actually have a second used one as well) got the correct Ohms for each, and tried both, same result, so YES
Checked the voltage following their pictures got around 110, so YES
Says to replace the vacuum switch- that was actually one of the first things I tried.

Vacuum switch attached pic - I don't have that metal plate, what is its purpose?
On another note, my blower connects to the ICB board with a connector, see attached pic, not sure why, but it doesn't fit without it.

Any ideas?

Thank you!

 

[ajw22]

Do you know how to check for continuity and shorts using your multimeter?

At startup the heater board checks that the air flow switch is OPEN. If the air flow switch is CLOSED the heater will not start and will throw the AO code.

Once the heater shows the air flow switch is OPEN then its starts the blower and looks for the air flow switch to close indicating the heater has enough air flow to begin the ignition sequence.

The blower not starting says the PCB does not think the air flow switch is OPEN. Checking wires visually is not sufficient. You need to check each wire to the AFS electrically for continuity and that it is not shorted together.

There is also the possibility that one of the other safeties on the heater is open. Sometimes a heater throws the wrong error code.

@1poolman1 @swamprat69 may have ideas.

 

[ffabcd4]

Do you know how to check for continuity and shorts using your multimeter?

At startup the heater board checks that the air flow switch is OPEN. If the air flow switch is CLOSED the heater will not start and will throw the AO code.

Once the heater shows the air flow switch is OPEN then its starts the blower and looks for the air flow switch to close indicating the heater has enough air flow to begin the ignition sequence.

The blower not starting says the PCB does not think the air flow switch is OPEN. Checking wires visually is not sufficient. You need to check each wire to the AFS electrically for continuity and that it is not shorted together.

There is also the possibility that one of the other safeties on the heater is open. Sometimes a heater throws the wrong error code.

@1poolman1 @swamprat69 may have ideas.

Thanks for the response. Where can I find out how to test for this below, and what is AFS?

You need to check each wire to the AFS electrically for continuity and that it is not shorted together.
There is also the possibility that one of the other safeties on the heater is open.

Thanks again.

 

[ajw22]

AFS is the air flow switch.

https://www.youtube.com/results?search_query=multimeter+continuity+test

https://www.youtube.com/results?search_query=multimeter+short+circuit+test

 

[swamprat69]

This should be the manual for your heater https://ca.hayward.com/media/akeneo...UHS_Service_Installation_011717_RevT_9878.pdf Signature for your equipment and photos of the heater outside and inside (all components from various angles) would be very helpful. There are other things besides the blower, pressure switch and associated pressure switch tubing that can cause an AO error ( blockage to airflow and dirt in various components ). Would be happy to try to help with more info and photos.

 

[ffabcd4]

AFS is the air flow switch.

https://www.youtube.com/results?search_query=multimeter+continuity+test

https://www.youtube.com/results?search_query=multimeter+short+circuit+test

Thanks, I'll take a look.

 

[ffabcd4]

Thanks, yes, I found the manual when I was looking around for information. Do these pics help? Let me know if you require a different angle or close up of something in particular.

 

[ffabcd4]

This should be the manual for your heater https://ca.hayward.com/media/akeneo...UHS_Service_Installation_011717_RevT_9878.pdf Signature for your equipment and photos of the heater outside and inside (all components from various angles) would be very helpful. There are other things besides the blower, pressure switch and associated pressure switch tubing that can cause an AO error ( blockage to airflow and dirt in various components ). Would be happy to try to help with more info and photos.

 

[ffabcd4]

This should be the manual for your heater https://ca.hayward.com/media/akeneo...UHS_Service_Installation_011717_RevT_9878.pdf Signature for your equipment and photos of the heater outside and inside (all components from various angles) would be very helpful. There are other things besides the blower, pressure switch and associated pressure switch tubing that can cause an AO error ( blockage to airflow and dirt in various components ). Would be happy to try to help with more info and photos.

This should be the manual for your heater https://ca.hayward.com/media/akeneo...UHS_Service_Installation_011717_RevT_9878.pdf Signature for your equipment and photos of the heater outside and inside (all components from various angles) would be very helpful. There are other things besides the blower, pressure switch and associated pressure switch tubing that can cause an AO error ( blockage to airflow and dirt in various components ). Would be happy to try to help with more info and photos.

Thanks, I added a response and some pics. Thought I was replying to you but I think I just added to this thread instead. Had 14 pics but would only let me upload 10.

 

[ffabcd4]

Any last thoughts, suggestions, easy checks, before I call the pool store? Just clicks twice, then sits for a little, then AO. Nothing else happens besides clicks, no blower spinning, no air coming on. Could it be the blower switch wiring? How would I check, or replace that wiring?

 

[swamprat69]

Sorry to having been silent for a while but my brother has been visiting and "forced ?" me to play poker constantly for more than a week! Something seems "off" about troubleshooting so far and you have not given actual measurements that you took. I would suggest following troubleshooting chart for AO error on page 58 of the installation/service guide and reporting actual measurements that you take. If blower does not start up and ohms out correctly (blower ohms are different depending on the age of the blower!) and blower is getting correct power it should start up. Note that the blower IS NOT a permanent split capacitor (PSC) motor and has very little starting torque which means that any resistance to the motor bearings moving freely would cause it not to start ( could be confirmed by excessive motor amp draw when voltage is applied over the rated amp draw listed on the motor ). Also possible that deteriorated contacts on blower relay are dropping voltage below below rated voltage when the relay pulls in ( take voltage reading at pins when relay pulls in ). Report findings and readings and I will try to assist you.

 

[ffabcd4]

Sorry to having been silent for a while but my brother has been visiting and "forced ?" me to play poker constantly for more than a week! Something seems "off" about troubleshooting so far and you have not given actual measurements that you took. I would suggest following troubleshooting chart for AO error on page 58 of the installation/service guide and reporting actual measurements that you take. If blower does not start up and ohms out correctly (blower ohms are different depending on the age of the blower!) and blower is getting correct power it should start up. Note that the blower IS NOT a permanent split capacitor (PSC) motor and has very little starting torque which means that any resistance to the motor bearings moving freely would cause it not to start ( could be confirmed by excessive motor amp draw when voltage is applied over the rated amp draw listed on the motor ). Also possible that deteriorated contacts on blower relay are dropping voltage below below rated voltage when the relay pulls in ( take voltage reading at pins when relay pulls in ). Report findings and readings and I will try to assist you.

I'll take some readings and report back., thanks.

 

[ffabcd4]

This should be the manual for your heater https://ca.hayward.com/media/akeneo...UHS_Service_Installation_011717_RevT_9878.pdf Signature for your equipment and photos of the heater outside and inside (all components from various angles) would be very helpful. There are other things besides the blower, pressure switch and associated pressure switch tubing that can cause an AO error ( blockage to airflow and dirt in various components ). Would be happy to try to help with more info and photos.

If I did want to check this (blockage to airflow and dirt in various components ) which components should I look at that I can safely get to? I've never open up the heater before, so if I do, is there anything I should be careful of? I'm interested to go on in

 

[swamprat69]

Before opening up the combustion chamber to check for any blockages I would follow the AO troubleshooting guide in the heater manual on page 58 and report all of the readings that you get. As to the age of the heater, you should be able to get that from tag on the heater with model and serrial number or the components in the heater such as the gas valve many of which have a 4 digit number noting date of manufacture such as "0916" denoting september of 2016. Also with the heater off if you manually spin the black blower cooling fan on the end of the blower nearest the gas valve does it spin freely and slowly stop or does it stop right away or stop abruptly?

 

[ffabcd4]

Before opening up the combustion chamber to check for any blockages I would follow the AO troubleshooting guide in the heater manual on page 58 and report all of the readings that you get. As to the age of the heater, you should be able to get that from tag on the heater with model and serrial number or the components in the heater such as the gas valve many of which have a 4 digit number noting date of manufacture such as "0916" denoting september of 2016. Also with the heater off if you manually spin the black blower cooling fan on the end of the blower nearest the gas valve does it spin freely and slowly stop or does it stop right away or stop abruptly?

Hopefully this helps out. I checked everything in the list on page 58. I've tried all 3 switches, and both fans, and swapped the pressure hose with another silicone hose. Is there any way to test a switch? And THANKS!

 

[ffabcd4]

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[swamprat69]

A lot of things seem to be "off" in what you are showing. The 3 pressure switches seem to have different WC setpoints ???? Which one was the correct original ?? Original Blower motor FDXLBWR1930 has 1 black wire and 1 white wire, but the one that you are showing has 1 white wire and a (blue+red) wire??? Are any of these parts OEM original ? You can't just replace parts with something that "looks" the same !

 

[ffabcd4]

A lot of things seem to be "off" in what you are showing. The 3 pressure switches seem to have different WC setpoints ???? Which one was the correct original ?? Original Blower motor FDXLBWR1930 has 1 black wire and 1 white wire, but the one that you are showing has 1 white wire and a (blue+red) wire??? Are any of these parts OEM original ? You can't just replace parts with something that "looks" the same !

The blower was already installed when I bought the house 8 years ago. I've never had an issue with it. And when I look up that model 2 wiring versions do seem to come up. Could it be something to do with the board it's connected to? I believe the pressure switch which came with the house was the one showing NS2-0556-00. When I first received the AO error, the first thing I tried was replacing the pressure switch. Looked up the model number and these showed as replacements for it. One of them, I believe the NS2-1678-00 was working fine. possibly the NS2-1134 is wrong.

 

[ffabcd4]

The blower was already installed when I bought the house 8 years ago. I've never had an issue with it. And when I look up that model 2 wiring versions do seem to come up. Could it be something to do with the board it's connected to? I believe the pressure switch which came with the house was the one showing NS2-0556-00. When I first received the AO error, the first thing I tried was replacing the pressure switch. Looked up the model number and these showed as replacements for it. One of them, I believe the NS2-1678-00 was working fine. possibly the NS2-1134 is wrong. You got me thinking, I'm going to place that original pressure switch back and start from the beginning again. Will get back to you. ***just had a look at that pressure switch ( NS2-1134) packaging. They sent me the wrong part and are refunding me on that! Ordered another. Once I've tried that I'll let you know.