Laars Lite 2 shutting off early

[MrJonMan]

Model LD400N

Polaris SOL 1000 controls (which I despise)

Roughly 10yrs old....just bought the house with it in August.

So if I turn on the spa and heater, it ignites and warms to roughly 90-94 degrees then cycles off. I discovered the water temp sensor had gone bad, as I'm in Houston Texas but it said the temp was -34, haha.

I replaced that today and it now is giving me a reading within 3-4 degrees of the floating thermometer, however still the heater won't stay on past 90-95 degrees.

Basically as soon as it starts to feel good, 10min later you notice it's a chilly, then 10min later it starts to feel good again, and so on.

Ideas? My next ideas were he high limit switch or the heater temp sensor, but if would like to have a decent idea before I just start dropping $ on shots in the dark. :?:

Thanks in advance!

 

[ps0303]

As a test, you can remove the high limit and put a jumper wire in its place and see if the temp goes beyond the 90-94 you are seeing.

 

[MrJonMan]

As a test, you can remove the high limit and put a jumper wire in its place and see if the temp goes beyond the 90-94 you are seeing.

I was wondering about that....guess I need to locate the high limit

 

[MrJonMan]

It should be located where the water inlet/outlet is, right?

 

[MrJonMan]

Well I took out both high limit switches, put a wire in their place, same story, shut off

 

[MrJonMan]

I suppose there is a chance the wires weren't done correctly, I can get the 2 pack locally for $55 so figure it might be worth just replacing, but I don't know what the next step in diagnosing would be.

Making me mad bc it's getting into the 30's this week & I want to use it!

 

[ps0303]

You can carefully remove them from their socket and then put a jumper wire in their place and see what happens.

 

[MrJonMan]

I replaced them today with brand new ones.....still same problem, takes about an hour, gets to 90-95 degree & the heater goes into cool down mode. Ugh.

Next idea?

 

[ps0303]

The other part to check would be the temp sensor. You will need a ohm meter to check it to see what the ohm reading is when it stops heating. Look at page 33 section 10.4.6.3 and it will tell you what the ohm reading of the sensor would be @ around 90 degrees.

Link to manual.
https://www.parts4heating.com/v/vspfile ... andyLD.pdf

 

[Pool Clown]

Check to make sure that the thermostat ON the heater is set to the highest (hottest) setting. Automation does not by-pass the heaters thermostat, it just turns it on and off.

P.S. I hate the Polaris SOL too!

 

[MrJonMan]

Yea the temp is turned all the way up, trying the temp sensor next

 

[Pool Clown]

"Basically as soon as it starts to feel good, 10min later you notice it's a chilly, then 10min later it starts to feel good again, and so on."

Are you saying that the heater is cycling? If so, this maybe a by-pass problem and the high limit tripping is a symptom of that.

 

[MrJonMan]

Yes it's cycling

 

[Bah]

Mr jonman. Did you ever get resolution on your heater cut off. I have exact same unit and exact same problem. In Houston as well. Had to replace the ignition controller already but now issue of spa kicking off at 97f. Thinking to replace the thermister as a next step.

 

[MrJonMan]

Just fixed it Thursday, it was the temp sensor inside the heater, used it 3 times since with zero problems.

 

[Thmitz]

Hi I'm having the same problem you did. I'm pretty sure it's the temp sensor. I have new one... where exactly is the temp sensor located?