Selgas
Sounds like you have a tempering/mixing valve fitted controlling the maximum temperature to the areas that you are currently getting luke warm water too. Hire the services of a registered Plumber to check it all out for you.
It is also possible you may have a faulty faucet causing the mixing of both hot and cold water as well.
As I said have it checked out to be sure. 
Selgas Services Ltd
Craftsman Gasfitters, Plumbers, Electrical Service Technicians
