I have an old spa.
At some point recently it stopped heating water. It still circulates,
I have traced the problem to a faulty thermostat switch (with a knob
to set desired temperature).
The proof of this is that if I electrically connect two terminals of
the switch, then the heater relay closes. That is not happening if the
thermostat is set even to its highest setting.
Here's the weird part. Three years ago I had the same problem -- when
I moved into this house, the spa was not working. So I went to a local
dealer and bought a new thermostat and installed it. It lasted about
that long, and now it i s bad again. WTF? Any idea just what might be
possibly wrong, or are these thermostat switches really that bad?
Yes. That type usually has "points" like an older car distributor.
Shut the power off and slide some very fine (400/600) sandpaper between the
points and pull it back & forth.
Make sure you get BOTH sides.
I think that that's it!
An additional tidbit is that as I rotate the knob of the thermostat, I
do hear a "click". At approximately the point that I would expect. So
the thermostat "clicks", but somehow does not close the contacts.
So, your suggestion is right on the mark, but I want to hear a little
clarification. Do I need to take the t hermostat body apart?
They click shut but since the points are burned, the current has a hard time
I didnt, I just shut off the current, took one (front) side off the control
box wherein the thermostat is found, wound the thermostat switch to its
lowest setting (opens the point gap more) and put the sandpaper or a "points
file" in there and smoothed them down. I also found a small hole in the
thermostat housing that allows an 'allen key" to be inserted..when it is
turned, you can see it changing the gap- it allowed me to put the desired
setting into the dial..I put the dial about halfway, then turned the
allenkey til the points clicked.
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