clogged cold water lines

This past weekend we had a break in a water line outside of the home. The line was repaired, when water flowed back into the house we experienced two problems. The tankless hot water heater quit heating and the master bathroom lost water pressure on the cold water side only. We are working with the water heater company to try to resolve the heater issue. I am assuming that some debris got into the water line and has clogged the cold water line somewhere between the hall bathroom and the master bathroom as the cold water works fine up to that point. The toilet, sink and bathtub have only a trickle on the cold water side in the master bath. Hot water side has plenty of water it's just not hot. How do I go about clearing the line to the master bath? I have a slab foundation.

 

You just need to remove all cartridges and flush the lines out one fixture at a time..All aerators at faucets may just be clogged so try those first, as well as shower heads..

The Tankless has a screen on the cold inlet... Probably just need to clean that...

 

When the aerators are off run the water to clear lines.

 

It's too late for your house but in the future when work on the water lines is finished, open a outside spigot and let it run full bore for 30 seconds or a minute. Sediment will not get pushed to fixtures that are not using water. So, if you make the first thing a spigot you can flush the sediment out of the lines without contaminating every side line leading to every faucet or device in the house.