There are not close enough to the repair to have been super heated by the repair ???
Most mixers will only take a maximum temperature from the ht water system, NO more.
If this is the case then the problem, and cost, is the repaires problem.
All advice is given with-out seeing the job, and hence all advice MUST be taken as advice with limited knowledge on the exact situation. NO responsibility can or will be taken. And yes, I am a licensed Plumber and Drainer with my own business in Brisbane Australia