i had a problem with a jet pump had someone come in and replace the valve. they said to give it a couple of days to let the sand died down, then run the water. we did that now it seems that our pipes are clogged with sand how do we get the sand out of the water heater and water comeing out.we seem to have cold water, but now hot. we check the tank it is hot and the water in the tank is hot( we tested the spout on the bottom of the tank. it worked it was hot) but we don't get any hot water in the sinks.kitchen and bathroom. cold water comes out not hot! please let me know what to do. i need help!!!!!!!!