Racinbob

We have the AquaPure 700. We started getting 2 error codes last weekend. 172 and 180 alternate. Tonight it's 172 and 185 (the 180 went away). I found the 180 code here (not heating sensor) but not the 185. I've gathered that my flow sensor may be bad. I did clean the cell and sensor. At times it works fine but then the codes come back as they did tonight. Does replacing the sensor sound like the thing I should do? Also, the manual only goes up to error code 175. Does anyone know where I can get the higher codes?