This morning we woke up with no cold water in the bathroom sink and shower but toilet is fine as well as the hot water. No problem with kitchen hot and cold water supply. Two days ago, when the temperature was really low, we had the same problem. My husband suspected that it's freezing pipe. But I checked online and found an alternative cause - air lock. We followed the process and it seemed to work. Last night the temperature dropped again and the problem repeats itself. I am now suspecting that it's the freezing pipe. But why the toilet is fine, though, in the same bathroom?

Would the bathroom lavatory a shower be a outside wall? Is the toilet on the same wall? Back to you, Tom