2004 hot springs grandee
Spa not heating up. Spa was working great after I changed the water clean filter with those. The water will not heat up. Cir pump working I can see water running through. Did not see water running through circ pump discharge hose until I disconnected the hose from the ozone system. I left that hose disconnected. Good bubbles coming from the heater return and drain into the spa. Took the cover off the control box and noticed continues two lights on “HTR ON” and the light above. Still no heat.
Should the water from hose from the No Fault heater be hot? Should the metal tubes be hot on the heater? Just trying to see from a touch stand point if the heater is working.
Also when I turn the power off and that turn it on he here a clicks and that a few seconds later I heard clicks again. Like things are turning on.
All pumps work and no breakers trip

I would check the heater relay board in the main control box. It is the circuit board on the left side where all of the power wires hook into. Look to see if any of the small black relays have any burn marks around them. You can check voltage through the relay if you have a meter.