Not without help.

Think you could explain the situation a little better?

Scott

The spa has stains.

If the stains are turquoise, then yes they were more than likely from the heater.

Usually when they are caused by the heater, usually something with the chemistry was not correct. This something with the chemistry is almost always the pH, but sometimes can be caused by bromine, and excessive water flow. Improperly applied chemicals and their feeders can also cause corrosion of a heater.

After the heater corrodes the copper goes into solution (waters) and eventually precipitates out onto the plaster.

thanks "racket". I appreciate your prompt response.

Are you new to pool care?

Scott