With regards to the membrane and control unit, I did manage to be successful in adjusting the pool water temperature control to the desired water temperature, I did have to press the temperature control a couple of times. The temperature readings are not as clear as they used to be but the monitor works. The pool water temperature was actually above my requested adjustment in the past.
With regards to the loud pitched whine it still occurs after an hour of heating but disappears entirely when I take the pool heater covers off allowing easier air access. A couple of years ago Manitoba Hydro replaced the gas meter, and I was advised to replace the gas orifice with a smaller size and did so accordingly. Also a mouse had chewed the endcap mixing tube grill. However John at Aquatech provided me with a circular grill instead of vertical. Ever since this change I have been experiencing the loud pitched whine after an hour of heating with the jacket covers on the heater.
You have mentioned that should check with Manitoba hydro if the proper gas intake occurs from the meter. Do they do this? Also the manual refers to testing the regulator setting on Page 19. Do you this as part of your diagnostic.
Finally what is the effect of their loud pitched whine – dangerous, breakdown of heater, etc
Thanks a lot for you quick response.