sn code

[bigred28]

I have a Sn code on my image spa . The hot tub will not start up and doesn't trip the gfi breaker I tested the sensors they test the right resistance for the water temp so that tells me the sensors are ok . It has a balboa system 2000le . Thanks

[Jersey Hot Tub Repair]

Do both sensors have the exact same resistance, or is one at the top of the allowable range and one at the low end?

Is the SN message flashing intermittently with the temperature, or is it just blinking on and off.  If alternating with the temp, the spa isn't sure it's a sensor error.  If just blinking on and off, the error condition is verified.

SN usually means the sensors are out of sync - they are giving different temperature readings to the circuit board.  Balboa allows up to a 2 degree variance in temperature between the sensors, than assumes the tub is heating unevenly and shuts down the tub to prevent damaging it.

Look at where the sensors are attached to the circuit board.  Do you see any corrosion?  Look for a white residue in the tiny plug or jack.  Even if the sensors have the correct resistance, corrosion will affect the circuit board from being able to read it.

I would remove your filters and see if the problem goes away.  That's not a typical error message for a low flow situation, but it's quick easy and free to test.

It's possible the circuit board has a problem and isn't reading the sensors properly, but it will cost you far less to test the problem and replace the sensors than the circuit board.  And the problem is almost always the sensors.

Dave

[bigred28]

Thanks Jersey, the Sn code is not flashing at all it just stays on . The sensor in the tub reads 16.0 and the sensor in the heater reads 15.4 resistance @ 100 f . That's ok according to the chart from balboa . The only other thing it does when power up the screen says 0 then 100 then Sn no pumps or anything will run. Thanks for any help. !!

[Me Not You]

BigRed28

Did you find a solution? 

I am having the same problem.