so heres an odd one, with the heat on car will only warm to the quarter mark and wont go past. Heat off the car will warm to the normal mark but as soon as the heat is turned back on it will drop back to the quarter mark in 3mins or so.
Water pump was just done but the problem was happening before hand.

 

Its possible that your thermostat is stuck open and not closing causing the car to keep the cool water cycling rather than it closing and keeping the temp at 180*

 

Replace the thermostat....