2006 Hot Spring Sovereign II - NO HEAT

Sorry if this is redundant but I’ve read a few posts on here with similar issues and after following the advice and troubleshooting I still haven’t identified the problem.

We recently bought this 2006 Hot Spring Sovereign II hot tub used from a US army service member. It was dry and in storage so we had no way to check it but he swore that it all worked. It looked good and was a very fair price so we trusted him and bought it. Then it sat outside empty and unused for a month while our deck was being repaired in the Atlanta, GA cold and I’m sure wasn’t properly winterized (temps dipped below freezing a couple times). It ended up with a bit of rainwater in it too from having a leaky cover. But we finally got our deck finished and cleaned it up well and can’t wait to use it! Only problem is the heater isn’t working. Very frustrating... Please help. I’m an engineer and have done and observed the following in this order. If you are good at this and know this brand please provide input:

- After cleaning and sanitizing we filled the tub with garden hose stuck down in the main gray standpipe (at this point all filters were removed and trashed while we waited on new ones)

- Adjusted water and chemicals per instructions. Tested all pumps and jets. All seemed to be working fine. Red Power light solid. Green light off. Let it run to keep circulating water. Used clean microfiber clothes as filters while we waited on our filters to arrive.

- New filters arrived and installed next day. Power cycled spa. Waited 24 hours

- Water still very cold at 60 deg F Red Power light solid. Green light off.

- Circulation pump seems to be functioning fine because the “soothing stream water feature” is flowing well and ozone bubbles are steadily rising from drain in the bottom of tub

- Read manual downloaded from internet several times (could be different year model manual).

- Checked electrical panel wiring and breakers. All are working fine

- Checked power entering spa circuit board with voltmeter and I get ~230V on both circuits coming to spa board.

- Reset power to spa for 1 minute several times in case of high limit thermostat tripping. Don’t know how to reset Integrated pressure switch (manual says correcting water flow issues will reset it)

- Waited another 24 hours and still 60 deg F

- checked spa main board lights. Lim OK is GREEN. Htr ON is RED. see image attached below

- checked heater relay board power terminals to heater wire. Got 113V on each leg to ground (checked both legs). I checked this with spa running and heater terminals connected

- Shut off spa at panel. Removed heater wires from heater relay board terminals. Put voltmeter in Ohm mode. Checked resistance accross Red and Black wire going to heater and got 11 Ohms.

- Felt around for a high limit thermostat reset button on heater but did not find one (my heater has blue sticker shown below)








ANY IDEAS FROM HERE?

Could my heater be bad and still read 11 ohms across?

Could I have a water flow/blockage issue even though main board shows Htr ON RED?

Not sure what to do next. Please help. See images attached.

THANKS GUYS!!!