We inherited a Prodigy spa by Hot Spring with the home we bought last year. The green light keeps flashing, even after we've drained, cleaned and refilled the tub, as well as installing new filters. The Watkins (manufacturer) customer service told us the temperature sensor needs replaced.

Is this something we can do or will we have to have the authorized service guy out and pay big bucks?

You probably do it if you are electrically and mechanically inclined. Get me the serial number of the spa and I will see if I can get the sensor for you.

I think we'll probably give it a try at least . . . is it easy to locate to replace? If we can find it, it should be easy to replace (we're hoping!) Where do I find the serial number?

I can try and locate it if you one you get me serial, it us usually inside by the spa control on a silver tag.

Okay, thanks, Jeff. I'll try to find it and let you know. Any idea on a ballpark figure for the cost?

Also, is there anywhere to get schematics of the hot tub so we know where things are located? Didn't find anything in the manual.

Only place I know of to get the schematic is a Watkins dealer. Price, don't know yet.

Okay, Jeff . . . the serial number is H2A1107.

Working on it, I will let you know, it will probably be tomorrow.

The part number you're looking for is 38415, but the tech support at HSS may have told you that as well. It's very easy to install

It retails for 15.40

A couple of notes...

Before anything is replaced, it's always a good idea (whenever possible) to test the part you're considering replacing. Just throwng parts at a problem is not a good idea. Just because the "temp sensor fail" light is flashing, it doesn't mean the temp sensor is bad......
Both of the thermistors (high limit thermistor and temp. control thermistor can easily be tested with an OHM meter, set @ 20k.
Leave the spa unplugged overnight, then simply meter each one, the readings should be nearly identical. If they aren't, go ahead and replace them both... when one fails, the other is usually not far behind....
The thermistors screw into the top of your heater (NO FAULT 6000), one right next to the other, both on the same end.

Each thermistor has a small wire that has a harness on the end that plugs into the SIDE of the control box. You do NOT need to take the cover off the control box to unplug the harness. It is at this end you can use your meter and measure OHMS (resistance)

However, the green flashing light, although it's supposed to indicate a failed thermistor, will also flash during another common failure... When the circ pump fails, it still generates a fair amount of heat. Since the circ pump is located very close to the temp. sensors, the spa "thinks" one of the temp sensors has failed, when in fact it has not.

So....... just be very sure you are getting flow from your 24 hour circulation pump (Silentflo 5000). The output from this pump doubles as the drain on your spa.

Hope this helps.
Good luck!