Am I justified to ask for boiler replacement?

I'm not happy with the boiler in my council flat. It takes around 30-45 minutes to heat water for a bath. If use one kitchen sink worth of water to wash dishes and try use remainder for a bath an hour later then the water will be cold. I'm guessing this is because the boiler fills back up with cooler water!? There's no time controls on it either so I have to manually switch it on 30-45 minutes before I need hot water. This is very inefficient and inconvenient however with councils is this more than they are required to offer?