Re: Water pump or Thermostat or Both
When the alarm went off did the engine appear to be overheating? Could you/did you touch the powerhead. It should be hot, but you should be able to just barely touch it without burning yourself. I think its temperature when running should level off at about 145 degrees F if all is working well. If you confirm that it is overheating, it would a least tell you that your alarm is not faulty. (please note: I am not suggesting you now go and overheat your motor just to confirm this, but if my alarm went off I would certainly have definitely taken the cover off and checked it out at that time).
If it is overheating, I would want to look at that thermostat to ensure that it is opening. The easiest way to test this is to put it in some water in a pot and put it on your stove. At about 140 degrees F is should start to open and be fully open at about 150 deg.F.
And if all of the above is OK then it must be the water pump system. Since it is peeing out the tell-tale it may end up being a blockage in the system, but I would take a look at the impeller first, since that is where the water flow starts anyways.
