Is it worthwhile upgrading a gas hot water heater for efficiency?
We've got a RUDD P40-7 gas hot water heater that's about 9 years old. It has a lousy energy efficiency of .056
Monthly use of 31 therms (which has been typical) of gas cost us $64.48 (Keyspan in Boston) which is $2.08 per therm net.
Is this worth replacing with something more efficient? Our only other gas use is for a 15 year old gas Whirlpool clothes dryer that does 4-6 loads per week and a 10 year old GE range which cooks about 3 meals per week.