Student or Learner
For the following sentences, the preposition to the word "shower" would be "a" or "the"? Which would be correct?
The water doesn't get hot enough for a/the shower.
The water is not hot enough to take a/the shower.
The water is not hot enough for taking a/the shower.
You are looking for an article, not a preposition. A and The are articles. A is general, and The is specific.
When you refer to a shower, you refer in general to the concept of showering, to any shower. Not hot enough for a shower, means not hot enough for one to take a shower, at any time. Not hot enough for the shower means that that particular fixture simply won't function with water of that low a temperature.
Might not make sense with showers (as you can take a cold shower), but it does make sense if you change shower to dishwasher, as most dishwashers require 180-degree water to work at all. They will run, but they will not clean the dishes or even dissolve the soap if the water is not hot enough for a dishwasher, or the dishwasher if you want to specifically mention the particular dishwasher that you have at home.