Originally Posted by TxBuilder
It's odd I replaced a 30 gallon with a 50 gallon, both same brand. Factory pre-set on both is 120 however the 50 gallon while it stays hotter longer isn't as hot as the 30 gallon despite being set the same. They recommend not going over 125 so I set it right at and now it's as hot as the 30 gallon set at 120.
that is because the same reason different size ovens take different amount of time to cook things at the same temp. It takes more time to heat more water. I am not sure but I think a bigger water heater also produces a little more hot water pressure too because there is a certain amount of vapor/air etc whatever is in there causing it to use a little more water per use than the smaller one did.
I have a 30 gallon gas water heater it's set very low because originally there wasn't any water heater here. This house didn't have anything but a toilet when it was first built and if you wanted hot water you had to boil it the water pipes were installed by a previous home owner and run about six feet outside of the house to the main wet wall which has the tub/shower and a sink on each side in the summer being I'm in Arizona I don't even need the water heater it's hot already from the sun in the winter however I turn the water heater up a little or else take cold showers.
If the price of copper (AU) had not gone so crazy I would have replumed the entire house over the past few months and put the water heater in it's own outside closet which is how most of them are here in Arizona. But other things need to be purchased before doing something that's not an imidiate need. For now my water heater is in my laundry room which was once no room at all a previous home owner closed in the back porch and made a laundry room.