Hot Water Tank and Mixing Valve

[essjay]

Finally have my water heater tank ready to go. The proper method to use the water heater from what I've read is to first let the tank fill and open a faucet for the hot water. When the faucet flows the tank is filled and power can then be applied to the tank. But if a thermostatic mixing valve is on the tank hot water outlet, will it cause the hot water to NOT flow if the temperature is incorrect? The water feed/supply into the tank is from my boiler hot water line.

 

[hj]

If the mixing valve is connected properly it will ONLY flow hot water until the temperature reaches it setting. Most plumbers vent the air using the T&P safety valve.