Hayward H400FDN AO error question

Loubalpool

Member
Apr 3, 2021
12
95020
I've got a Hayward H400FDN (up to October 2010 Model, according to the troubleshooting guide) and I am having an AO error after replacing both the display board and control board as well as the blower and vacuum switch.
Steps taken:
  1. Jumped the vacuum wires and it changes to a AC error so the wiring to the switch seems fine.
  2. Tested the voltage and it's sending 128 to the new blower when a call is made but the blower isn't starting.
  3. If I trip the breaker while it's on the pool or spa setting then turn the breaker back on the fan spins up for 20 seconds or so but then shuts off with an AO error.
The only thing I can think of is that the new board is an older model then the new (Ver 4 vs Ver 18) and has a different connector for the Pool, 24VAC, Spa connection (blue direct wiring vs a small 5 pin connector).

Any help would be greatly appreciated.
Lou
 

Loubalpool

Member
Apr 3, 2021
12
95020

JamesW

TFP Expert
Mar 2, 2011
28,291
It looks like the heater is from February 2008.

Is the new bower part number FDXLBWR1930?

Where are you measuring the voltage going to the blower?

Can you show a picture of the blower motor label?

What is the supply voltage to the heater?

Is the correct voltage selector plug installed?

Note: Do not install the wrong plug or you will damage the heater.

Are all of the fuses good?

Check to see if the heat exchanger is sooted.
 

Loubalpool

Member
Apr 3, 2021
12
95020
First of all, thanks for your help.
That is the part number of the blower, It's actually FDXLBWR1930 FD, I'll post a pic in the morn. I'm measuring the 2 left pins of the 3 pin connector on the inducer port on the control board just as the troubleshooting guide shows. It's wired in 240 and the correct plug is in it. I'll check for soot in the morning.
One thing that concerns me is the new control board I got from Hayward is the IDXL2ICB1931but the board I pulled out is a 1101643301 which is nearly identical but had the molex connector vs the direct wire connections on the pool/24VAC/spa wiring.
 

Loubalpool

Member
Apr 3, 2021
12
95020
Does the motor voltage say 115 or 230?

Is the heat exchanger clean?

Is the heater leaking water?
Fan says 115v, no leaking water and the top of the heat exchanger was clean. It fires up the fan if I trip the breaker while it's in a heat call and then turn the breaker back on, it just wont fire up the fan normally. When I select pool from the panel the relays begin to click, the display shows the current temp as it's starting up and after about a 45 seconds I get the AO error ( I assume because the fans not starting up ).
 

Enjoying this content?

Support TFP with a donation.

Give Support

Loubalpool

Member
Apr 3, 2021
12
95020
Again thanks for your help, if I could trouble you one more time. I've continued to troubleshoot and I think I have it narrowed down to the limiter switches. When I jump contacts on the water pressure switch it exhibits the same failure, when I jump the limiter switch contacts it starts to fire up then gives me a LO error with no temp reading on the LCD. When I wire them back up I get the temp reading but the fan doesn't fire up.
 

swamprat69

Well-known member
Mar 30, 2019
600
Las Vegas, NV
Jumping out wires at an inappropriate time during the sequence of operation will in itself cause a fault code as will turning off the pump breaker at an inappropriate time during the sequence of operation. I understand that you have a new display board, control board, blower and vacuum switch. What happens when you try to start the heater as you normally would at this time? Does the blower not start when the heater should actually be asking for heat?
 

Loubalpool

Member
Apr 3, 2021
12
95020
Correct, the blower does not start when the heater calls for heat.

My startup process:

Turn on pump to 2200RPM (about 50GPM?) select heat on the front panel (we have no automation or remote panels).
Heater shows temp of water flowing through, 3 relays click, fan does not startup 45 sec - 1 min later the heater shows AO.
Turn off pump, fan on heater turns on and runs for 20 seconds with error LO, no ignition or flame that I can hear then shuts down.

New Parts
Control board, display board, blower, air switch, water pressure switch, wiring harness.

Thanks
Lou
 

swamprat69

Well-known member
Mar 30, 2019
600
Las Vegas, NV
Just to confirm... when you try to start the heater, you are showing 128V to the blower motor with the blower power connector disconected. With the heater off and the blower power plug disconnected, you are measuring the correct resistance for the motor windings. If so, you should measure the voltage to the blower motor as the blower tries to start with the blower power connector connected to see if the voltage drops due to poor blower motor relay contacts.
 

Loubalpool

Member
Apr 3, 2021
12
95020
Just to confirm... when you try to start the heater, you are showing 128V to the blower motor with the blower power connector disconected. With the heater off and the blower power plug disconnected, you are measuring the correct resistance for the motor windings. If so, you should measure the voltage to the blower motor as the blower tries to start with the blower power connector connected to see if the voltage drops due to poor blower motor relay contacts.
128.5v from the inducer port on the board with no connector on it as well as 4 ohms on the connector to the fan. There's not really any good place to test from on the blower. The wires are integrated into the windings and I cant get my probes behind the blower to get to the black wire, but based on the fact that when I try and start it without the pump running the fan fires right up should mean that the relays are fine. I've ordered a new board (I've been reading that it's not uncommon to get faulty boards from hayward) in hoping that all this chasing around of problems could just be tied to a bad part on the board.

I'm still a little concerned that I'm unable to find my exact board from hayward (the board with the 3 pin connector vs the 3 pin direct wire, blue thing).
 

Loubalpool

Member
Apr 3, 2021
12
95020
128.5v from the inducer port on the board with no connector on it as well as 4 ohms on the connector to the fan. There's not really any good place to test from on the blower. The wires are integrated into the windings and I cant get my probes behind the blower to get to the black wire, but based on the fact that when I try and start it without the pump running the fan fires right up should mean that the relays are fine. I've ordered a new board (I've been reading that it's not uncommon to get faulty boards from hayward) in hoping that all this chasing around of problems could just be tied to a bad part on the board.

I'm still a little concerned that I'm unable to find my exact board from hayward (the board with the 3 pin connector vs the 3 pin direct wire, blue thing).
Thanks for your time, I really appreciet it.
128.5v from the inducer port on the board with no connector on it as well as 4 ohms on the connector to the fan. There's not really any good place to test from on the blower. The wires are integrated into the windings and I cant get my probes behind the blower to get to the black wire, but based on the fact that when I try and start it without the pump running the fan fires right up should mean that the relays are fine. I've ordered a new board (I've been reading that it's not uncommon to get faulty boards from hayward) in hoping that all this chasing around of problems could just be tied to a bad part on the board.

I'm still a little concerned that I'm unable to find my exact board from hayward (the board with the 3 pin connector vs the 3 pin direct wire, blue thing).
New board same problem, again it's a version 1 and mine is a version 18 (it's getting returned). Put in the old board for grins, fan immediately fired up but had a CE error and based on the old display board and old board It's not surprising (burn mark on each board).
 

JamesW

TFP Expert
Mar 2, 2011
28,291
I can respect your attempt to fix this, but this is why it's usually not worth fixing something like this.

You end up spending 10 to 40 hours trying to figure it out and hundreds or thousands of dollars on parts and in the end, you still end up with a heater that doesn't work.
 

Loubalpool

Member
Apr 3, 2021
12
95020
Solved. It was the board I was using for the replacement. My original board was a 1101643301 Version 18 vs the 1101321301 Version 01 I got from Hayward. Pretty much the identical board (except for the external control connector) but apparently it makes a difference. When using the Hayward parts page it pulls up the board as IDXL2ICB1931 which is the one I purchased but doesn't work with my model. I was able to purchase a used version of the board on ebay and it fired right up. On the brightside I probably have a couple of more years on the heater now that it's got nearly all new switches and electronics.
 

Attachments

  • image0 (4).jpeg
    image0 (4).jpeg
    519.1 KB · Views: 8
  • Like
Reactions: JamesW
Thread Status
Hello , This is an inactive thread. Any new postings here are unlikely to be seen or responded to by other members. You will get much more visibility by Starting A New Thread