John jpingy

A few year old (4-5?) legends series lsx masterspas tub. It is throwing a few different codes, SnS, dr, then dry (and sometimes Ohh) I suspect these are all related, maybe a non working circ. pump? I have tried to bleed the circ pump, I have checked the head of the circ pump for ease of propeller spinning and no clog. I have turned power off for 5 minutes after each attempt, still not good. (I also started with trying to run without filters, which are clean, just in case was a simple flow issue) Symptoms are that it is not heating. All three pumps seems to work, 2 at both of their speeds, and pump three at its only speed. It does, sometimes, rapidly raise the detected temp. up to the 118 shut off limit, but not always. Water temp is in the 65-75 range right now, as it's not been working for a few days, and it's getting into the 40's-50's at night up here in New England. Upon opening the front, there is a small pump maid by "Laing" that says circ. pump, and I don't seem to see this running. But truthfully, I don't remember if my circ. pump ever ran on its own? Never really paid attention. It does connect directly to the heater tube tho, so being that the dr and dry codes mean not enough water in the heater tube, am I correct in assuming that it is not pushing water into the heater and should start by replacing this? I'd hate to replace it, to find that it's a sensor or something, since the other two codes point to them as well. .? Please help, I am unemployed and can't afford serious costly service reps, but my wife has a bad back and needs this tub working. Thanks in advance, John