thermostatic mixing valve

[d1yd0c]

Hi, our heat and hot water are combined, so the longer the heat is on the hotter the water gets. We figure this has ruined the shower pump, so we are installing a thermostatic mixing valve to regulate the hot water before it gets to the shower pump. The instructions for the valve say that the maximum inlet temperature is 65 deg C! We know that the temperature in the hot water tank exceeds 65 deg C. Does anyone know of a mixing valve that would take higher than 65 deg C???