Jandy LT 400N Pressure switch light blinks... but switch seems to test good.

[Stole]

Hello, I am new to the forum so please redirect me if I am in the wrong place or have created any forum infractions.

I have an older model Jandy LT 400N pool heater... When it did work a few years back, it would work intermittently and display the pressure switch error blinking light. Other things came up so I just gave up and let it sit.. that turned into several years. Recently, I thought I would try to figure out what was wrong so I tried to fire it up.

When I did, I got a blinking pressure switch... I determined it was a bad switch using information from other posts so, I ordered a new one and installed it. I was ready to pat myself on the back but, when I turned it on, the pressure switch light is still blinking. I checked voltage across the switch while the system was running and it is closed -- I get voltage. I understand that the switch has an adjustment but I have dialed it with no effect.

Any help would be appreciated.

 

[ajw22]

Welcome to TFP.

Have you examined the wiring carefully? Made sure rats have not chewed on it or any loose connections? The wiring clean with no corrosion?

@Pool Clown @ps0303 ideas?

 

[Stole]

Thanks for the suggestion. I stripped the wires and replaced the old female spade connector with new. Still has pressure switch light blinking.

Then I noticed that I had a wire from the fireman block running up to the controller. I probed it and there was no voltage. I jumped across that and the heater fired up. Now onto finding out why the fireman switch failed.

Thanks for you help!