Jandy LT400 Temp Control Board Question

anonymouscuban

Active member
May 19, 2017
29
Porter Ranch
Hey all.

Been a while since I posted. Need collective brain trust again. I'm trying to revive my Jandy LT400 heater. It's not powering up. I've done the troubleshooting and it leads to a faulty Temp Control board. Unfortunately, this part is now obsolete and there is no replacement, as far as I can tell. However, I may have sourced a Temp Controller for the LX model. The difference between the two is that the LT has analog knobs where the LX has a digital display. Everything that I can see in the manual shows the same components for the 2 models other than this controller. Also reviewing side by side photos of both boards, all the connectors appear to be the same.

Anyone know if I can use the LX controller to replace the LT controller. Attach photos for reference.

LX Controller



LT Controller

 

Rossterman

Well-known member
Jun 5, 2016
470
Martinez, CA
They should work as all troubleshooting is identical between the two. To be honest I was at the same place with my LT a few weeks ago. The troubleshooting guide is poor and I came to the same conclusion that it had to be the board. I ultimately determined it was a bad sensor connection. Jandy screwed the pooch on that repair guide. Disconnect each sensor loop then Check all sensor loops for continuity disconnected from the board. What error are you getting?
 

anonymouscuban

Active member
May 19, 2017
29
Porter Ranch
They should work as all troubleshooting is identical between the two. To be honest I was at the same place with my LT a few weeks ago. The troubleshooting guide is poor and I came to the same conclusion that it had to be the board. I ultimately determined it was a bad sensor connection. Jandy screwed the pooch on that repair guide. Disconnect each sensor loop then Check all sensor loops for continuity disconnected from the board. What error are you getting?
Not getting any error. Nothing happens on the control panel. No lights. Nothing.
 

Rossterman

Well-known member
Jun 5, 2016
470
Martinez, CA
There is also an retired jandy engineer who lives in napa california that repairs jandy electronics for a decent price. I’ve used him to repair my iaqualink main board and saved me $100s of $ over replacement. Been working fine for 3 years now
 

anonymouscuban

Active member
May 19, 2017
29
Porter Ranch
Thanks everyone. Bob at BP Engineering called me back. I'm shipping my heater controller board to him tomorrow. Sounds like he will have it back to me within the next 2 weeks. $150 soup to nuts. Quite a deal because the used one I found was gonna cost me $450.

Again, thanks for everything.
 

anonymouscuban

Active member
May 19, 2017
29
Porter Ranch
Hey all. Hope you're having an enjoyable memorial day weekend. I wanted to follow up on my issue. I got back the control board from BP Engineering today. Hooked it up and the heater fired right up. It's now running like a champ.

Thanks to those that recommended BP Engineering to me. Saved me thousands on a new heater since the control board is no longer made and there is no replacement part. Highly recommend BP Engineering.