Our hot water heater is leaking and a new one is on the way. In the mean time my husband was afraid that it would get a crack and got all over the floor so we have been turning on and off the hot water heater valves. Now the hot water in our bathroom will not turn on. Only cold. What can we do?

What you have done is disturbed minerals built up in the pipe wall that is now clogging the inlet ports of your cartridges. The solution would be to shut the water off to the affected fixtures, pull the cartridge and check a clean the inlet ports. Expect more of the same when you replace the heater. How I would address this is by opening up a hot water And flushing the lines before I used any other faucets. Good luck, Tom