I have a friend that just had a new hot water tank and all new pipes put in. She can't get any hot water to the sinks or tub even though the pipes get hot. There's lots of cold water.

Did a licensed plumber install the hot water tank and pipes.. If so, need to call him back and have him fix this. If he refuses, tell him you will call the local plumbing inspector and see if a permit was pulled for all this work... because it should have been... and then if that didn't get him back, call plumbing inspector and ask him what you should do.

If not professionally installed, I figure issue could be pipes are clogged with sediment or water heater itself has clogged nipple at tank top.

Let me know more info. see what we can think of... Mark