Question about Hayward H Series Pool & Spa Heater 400k Btu Propane Gas Milivolt Ignition H400p1

I have an Hayward 400IDL pool heater and am getting Error Code AO. I have replaced the Vent Pressure Switch, Blower Vacuum Switch, Control Board, and checked the tubing. I still get an AO error code. I took the blower fan off and it spins freely and appears to be in good shape. Any ideas on what I should do next?

1 Answer

David Spradling

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Hayward Master
1,448 Answers

Check gas pressure if not enough it will not run call gas company sounds like you need more pressure

Posted on May 26, 2014

3 Related Answers

adam hudson

310 Answers

SOURCE: Hayward GAS HEATER KEEPS GIVING ERROR AO blower

This means that either the switch is bad, the wiring is corroded, the fan is not working, or the air switch tubing is broken or cracked. Follow the air switch tubing all the way to the end, remove it and check for cracks. This is the most common. Also check wiring connections for breaks, or corrosion.
If all looks well, replace the air switch.
Also, before any of this, make sure the fan is coming on at start-up.

Posted on Jan 16, 2011

Anonymous

4 Answers

SOURCE: I had code AO displayed on my hayward H250IDE. I

Check your wiring again on all the safety devices - Water pressure switch and both Hi- limits in the header.

Posted on Mar 01, 2010

Testimonial: "Thank you very much for the assit. I did find a kink in the vent safety switch. Thanks again."

Richard Johnson PE

91 Answers

SOURCE: AO error code

I would have to agree with you concerning the control module.

Posted on Aug 22, 2009

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1 Answer

AO error code on 250k btu hayward pool heater

Dear ,

Please try the below solutions,

Solution 1:
If the blower prover switch does not close after the blower starts the control will stop the ignition trial go into lockout. The blower will continue to run. Automatic reset is immediate after the switch closes
Solution 2:
If the blower prover switch opens unexpectedly during operation the control will shut down and attempt to re-light. If the switch does not close after the blower starts the control will go into lockout with the blower running. Automatic reset is immediate after error is corrected
Solution 3:
If the blower prover switch opens during the postpurge cycle (heater is not fir- ing) the control will display the error code. The post-purge cycle will be com- pleted once the blower prover switch close
Regards,
Samy

Aug 10, 2014 | Hayward Pool & Spa

0 Answers

Hey All!! I've been getting an "AO" Code on my Hayward H400 IDL pool heater. I've already replaced both the blower vacuum switch, vent pressure switch, control board, thermostat, hi limit thermostats,...

Aug 12, 2013 | Hayward 250k Propane IID Low NOx Universal...

1 Answer

The tube or hose that connects my hayward spa part # IDXLBWR1930 is broken. I am getting an AO error.

This tube connects between the blower and a vacuum or pressure switch. If the tube is broken the switch can't detect whether the blower is working. If you fix the tube then the system will continue its sequence and if it finds no more faults it should ignite and the heater can heat.

Aug 06, 2011 | Hayward series Heater Combustion Blower...

2 Answers

I have a Hayward H250 that wont ignite. When I set mode to to pool the blower comes on but nothing kicks in. then i get an error code of AO.

ErrorAO means BlowerVacuum Switch Open. If the blower prover switch does notclose after the blower starts the control will stop the ignition trial go intolockout. The blower will continue to run. Automatic reset is immediate afterthe switch closes. So you need to check this.

Jun 14, 2011 | Hayward H Series Electronic Ignition...

1 Answer

Ao appears after ignigtion

Either the fan is not working, or the fan prover (pressure switch) switch is stuck. If you can hear the fan going strong, it is most likely the switch. You may try to just clean it out, but you may need a replacement.

This error is produced when the blower prover switch does not close after the blower starts, the control will stop the ignition and go into lockout. Automatic reset is immediate after the blower prover switch closes.

If you keep having this problem, contact a reputable service company, especially if it's under warranty.

The link to the owners manual is below, it references fault codes, etc..

Hope this helps.

http://74.125.95.132/search?q=cache:4mAdY7bLfoQJ:www.haywardnet.com/products/Manuals/pdfs/Manual227.pdf+hayward+AO+error

Dec 30, 2010 | Hayward H Series Pool & Spa Heater 400k...

2 Answers

Ao error message in Hayward heaters

You didn't indicate exatctly which model you have. But on most the AO error code is :Blower vacuum switch
open error If the blower prover switch does not close after the blower starts the control will
stop the ignition trial go into lockout. The blower will continue to run. Automatic reset is immediate after the switch closes.Check to be sure combustion blower starts
If you don't have your manual you can download one for your exact model at : www.haywardnet.com

Jul 29, 2010 | Hayward H Series Pool & Spa Heater 400k...

1 Answer

I have an ao code and have replaced the vaccum switch and blower vaccum switch and still getting the ao code

Check the tubing going from the blower to the blower vacuum switch. If there are any cracks, missing, or cut, it will give the same code. Rodents like to chew on this tube. Also, if the blower is not coming on at all, then you will get the same code, and the problem is not with the switch, it is likely in the blower.

May 19, 2010 | Hayward H-series Electronic Gas Pool...

1 Answer