Hayward Heater - Unsolved error message

kprellop

New member
Apr 28, 2017
3
Manor
#1
Good evening folks!
I've got a Hayward model H400FDP heater which usually helps to take the chill out of the pool for the summertime swim season as well as provide our spa with that "hot" massage we all need at the end of every day. Two seasons ago the circuit board had to be replaced on the unit, and was done so (expensively) by a "certified" professional. All has been well. This year, I go to fire up the heater and get the "Sb" error. I promptly order a new one..plug it in, screw it down..and wahlah!! Heater fires up and we have a relaxing weekend. Flash-forward two weeks...I am getting the same error. Double-check the connections...everything "looks" good..as far as a circuit board, new bevel keypad, etc. So any idea why this error is popping up again? There is certainly no "stuck button" on this brand new keypad. ANY help or suggestions would be greatly appreciated as I've already psyched the kiddos up to swim this weekend!

Thanks in advance for any assistance!
KP
 

JoeGolan

Bronze Supporter
Nov 2, 2016
200
Palm Coast, FL
#2
Silly suggestion but have you tried pressing all the buttons, one at a time, to see if there is a difference in feel or to try and release the stuck button?

Also try uninstalling the pad and reinstall making sure you are not overtightening the board causing it to slightly warp.
 

ps0303

TFP Expert
In The Industry
Jul 6, 2011
3,956
FL
#3
Seeing that the keypad plugs into the display board and you already replaced the keypad, well you probably have a bad display board. Only way to know for sure its to get a new display board. Of course it could be another bad keypad that was ruined by a bad display board.

You can also try killing the power to the unit, turn breaker off, and then power it back on. That could clear the error but if it comes back, well then back to my first comment.
 

kprellop

New member
Apr 28, 2017
3
Manor
#4
Thanks for your responses.
JoeGolan: No, no button is stuck. With the last "bad" one, one button clearly was, but these on the new unit respond as expected. I checked all connections, inspected all points of connection and see nothing that should concern me. Since only two very short screws secure the board down, with the other corners being held in check by protruding pins, I don't see how it could be overtightened to the point of warping, but I'll definitely give that a closer look. Thank you.

ps0303: The display board was replaced by a "qualified technician" just last season. It appears to still be in tip-top shape. (I put that in quotes, because I didn't see his credentials, that's just what was advertised ha!) I did (and do) power off the unit and turn off the breaker before I expose the circuit board. Since my visual inspections have shown nothing, is there any more-advanced ways I can check the circuit board? I'm by no means an electrician but I have some experience with fiddling around with circuit boards & multimeters (i.e. checking continuity, inspecting for blown transformers, things like that.) Thank you for your response. I'd really like to cancel all else out before having to go with yet another display board.
 

ps0303

TFP Expert
In The Industry
Jul 6, 2011
3,956
FL
#5
No there are no testing options on the board. Just because nothing is visible doesn't mean it isn't bad. All I can tell you is to either replace the display board, keypad, or both again. Now obviously the display board plugs into the control board on the back firewall of the heater. Now there could be something up with it but again, replace that to see if that helps.

You can always call Hayward but I have a feeling they will tell you to replace the keypad again and or the display board.

This is part of the issues with these units. Hayward's have known issues and it is very frustrating to the DIY homeowner to fix.