Ao error on h series hayward heater - Hayward H Series Pool & Spa Heater 400k Btu Propane Gas Milivolt Ignition H400p1

SOURCE: Pool Heater will not light. (Flashes AO)

Mine had this problem, removed the blower and manually rotated the shaft. It was stuck, but once freed it runs fine.

Posted on Jun 11, 2011

SOURCE: H Series Pool & Spa Heater 400k Btu Propane Gas Milivolt Ignition H400p1: how do i fix the AO code on my hayward heater?...

AO will apply to your blower, blower tubing, or blower vacuum switch. You need to check these items.

Posted on May 20, 2010

SOURCE: 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

Posted on Jul 29, 2010

John Prohaska

• 1378 Answers

SOURCE: Hayward Heater Problem ''AO'' error. H400IDH

Thank you for posting your question here on Fixya.com.

It sounds as if the air activated switch the tube you mention attaches to is not working. Pull the two wires from it and connect them to simulate the switch closing. Start up the heater to see if you get ignition. If so, replace the switch.

If this answer does not fix your problem, please comment with additional details prior to rating the answer. Positive feedback is appreciated once your problem is solved!

John

Posted on Feb 14, 2010

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