Can anyone tell me why I don't have any hot water from any faucet in the house after having a brand new water heater installed? A visit from a plumber from Lowe's tole me the faucet needed replacing but I don't think every faucet in the house went bad at the same time.. it has to be something else.

Thank you:)

Is the water coming out of the HOT tap cold?
Is there no water coming out of the HOT tap?
Gas, electric or oil hot water heater?

The water is coming out of the hot twp cold and it is a brand new electric water heater. The kitchen sink has luke warm water at best.

I don't think they are all the fixtures are bad at the same time.

Some ideas, even the stupid ones:

1. Hot and cold reversed at water heater.
2. Not turned on at the fuse box.
3. Improperly wired.
4. Defective heater.
5. Wrong voltage and that blew elements.

Keep it simple gave you a load of places to start checking. You say only cold water comes out of the hot side. If the hot and cold inlets were reversed you would still get warm water outa the hot side on all faucets so we can discount that.
Number two is the place I would start looking. Check, at the breaker box and at the heater, to see if you're getting power to the heater.
Number three goes right along with number two. It's real difficult to miswire a heater but I guess it can be done. My bet's still on number two.
While not likely you still can't rule out number three. A defective thermostat or open connection.
Number five's doubtful, 110 volts won't blow the elements and not too many houses have 440 volts coming into the house and that's what it would take to blow out the elements.
Keep it simple should be complimented for touching all bases.
However there's one he missed.
6. If the power was turned on to the heater before filling the tank both the elements would be burned out and give you the exact condition you describe.
After determining that power is getting to the heater, check the elements and the thermostats . The luke warm water outa the kitchen faucet could be caused by the ambient temperature in the walls. Does it turn cold after you run it?
Good luck, Tom