I have Bradford White water heater model-MITW40L6EN12 with Honeywell gas controller sv9501m5109. These days we don't get enough hot water, just after 2 people take shower water is cold. Looks like water heater is running as the blower is on. But it doesn't heat the water for 20-30 minutes. Then it starts giving warm water and eventually turns hot. We are having very cold weather now a days (around 35 dgrees). Not sure if that is the problem. Also , how can I turn-up the temperature of the hot water?