On Dec 27, 3:22*pm, wrote:
On Dec 27, 4:10*pm, lesnpat wrote:

My spa is a 2002 Regency Spas, made by National Equipment Mfg. Corp.
The circuitboard system has no mfr. name anywhere. *There are both a
knob thermostat control on the box at the heater and a topside
pushbutton control at tubside. *The heater is electric Vulcan style
(flow-through 2" stainless tube). *Pump is 220v and heater is 110v.

The spa heats normally, but quits short of target because the topside
digital thermometer reads 5 degrees warmer than actual water temp. *Is
there a way to calibrate the digital system to get the reading in sync
with the actual water temperature?

I have a much older NEMCO spa, but the system may be similar. *With
mine, the system of measuring and displaying the temp is controlled by
the electronics inside the power pack and it's not meant to be user
adjusted. * *There are several pots inside the power pack that control
parts of the settings. *One of them does what you want. *I figured it
out by experimenting years ago, but don't know which one was which
anymore. *Plus your power pack is probably different. * I couldn't
find any info avail that detailed what's in the power pack or how it
works.

Are you sure it's really a calibration problem? * Is it always off by
about 5 deg at all temps?

Why not set to where you are comfortable or 5 up