Optima Flow Switch

[jflijohn]

My 2020 Optima will not heat up due to “open flow switch”.
I have removed the filter and operated it in that condition.
I have shoved a garden hose through the filer inlet pipe to purge air.
I pulled covers to inspect the flow switch, there was in-fact no flow, with a big air gap at the flow switch. I broke the line to purge the air and had heavy gravity flow (power & pumps off) from both directions.
I reinstalled the line which, is now packed with water. There is no air but still no flow.
There is also no flow from the waterfall circulation.

 

[RDspaguy]

Sounds like a bad circulation pump. Can you hear it running? Is it hot to the touch?
Post pics of equipment area and circuit board.

 

[jflijohn]

It runs and yes, it’s hot to the touch.
Does the circulation pump just pull suction through the filter or the other suction ports as well?
That’s the circ pump below the circuit board. The 2 pumps that run the jets are both operational with no issues.

 

[RDspaguy]

If it's running and the flow switch is open then the flow switch is stuck, there is a flow restriction, or the circ pump is bad.
It should be warm but not too hot to keep your hand on. If it's hot it's bad.
You should see a stream of tiny champaign bubbles shooting from the return in the footwell. If you do not, or they are big bubbles that go straight up, you have low flow from a restriction or bad pump.
I'd replace the pump.

 

[jflijohn]

If it's running and the flow switch is open then the flow switch is stuck, there is a flow restriction, or the circ pump is bad.
It should be warm but not too hot to keep your hand on. If it's hot it's bad.
You should see a stream of tiny champaign bubbles shooting from the return in the footwell. If you do not, or they are big bubbles that go straight up, you have low flow from a restriction or bad pump.
I'd replace the pump.

Just to follow up.
My pumps are still under warranty but just barely, so I didn’t want to start tearing into equipment and void the warranty, I really wanted to pull the volute case cover and get into the impeller… however

I pulled the fan shroud on the circulation pump motor and tried to turn it. It was completely frozen. The reason the motor was hot was that it was powered up but wasnt turning, so no fan to dissipate the heat. The motor is powered from the circuit board, I’m surprised there’s no overload protection, it was just sitting there buzzing. The circulation motor is only 1 amp at full load.

I managed to get it to turn slightly while it was powered up and then the volute case finally completely cleared the debris, next thing I know, the waterfall is pouring and the flow switch is closed and it’s now heating up.

Now I just need to figure out what the white debris was that plugged the pump.

Your help was much appreciated.

 

[jflijohn]

...duhh, its calcium buildup.

A chemist I am not

 

[RDspaguy]

Calcium buildup (scale) can release from surfaces in flakes that can lock an impeller. I'd say you've had balance issues, which will likely not be covered under warranty.
I thought you had a magnetic drive circulation pump. Glad to see they've gone to a shafted motor. Seals are cheap. The good news is that pump is probably fine.

 

[jflijohn]

Calcium buildup (scale) can release from surfaces in flakes that can lock an impeller. I'd say you've had balance issues, which will likely not be covered under warranty.
I thought you had a magnetic drive circulation pump. Glad to see they've gone to a shafted motor. Seals are cheap. The good news is that pump is probably fine.

That’s exactly what I was finding, white scale in the hot tub. I flushed the system with 2 gallons of 30% vinegar for a day and then changed my water out.
My flow switch was stuck open which is why the heater wouldn’t come on. I ordered a new flow switch however, after flushing with the vinegar, the flow switch is now operating correctly, I’m guessing that it was coated in calcium as well.
I’m still picking up chunks of calcium but I think that it’s releasing from all of the internal deposits point like the pump volute case and piping.

The bottom line:
It looks like I need to pay closer attention to chemical balance