Yesterday I noticed my tank temperature was way lower than usual. The heater is set to 84°, but the tank is only at 70°. Currently on my house it is 57° (it’s so cold due to our wood stove almost catching on fire). I assume that the heater just can’t keep up? But I don’t think I’ve noticed it this low before. The light still comes on indicating it is working, but it’s not heating up as much. The tank size is 65 gallons, with a 300 watt heater. Should I pick up a new heater? Or is there something I can do to fix this? Thanks everyone!