From my experience microwave heats up water so fast it doesn't matter. I've used coldest and hottest tap settings and as long as water level is right it works f

From my experience microwave heats up water so fast it doesn't matter. I've used coldest and hottest tap settings and as long as water level is right it works fine, provided you wait long enough after cooking for the rice to absorb the water. Usually I just wait 10 minutes. If it's still a little wet from cold water, I'll fluff the rice, stick the lid back on and wait a few more minutes (assuming this is using a microwave rice cooker).