I checked our water last night and this morning and it was around 8 degrees both times and we didn't have a frost this morning.
So that's quite cold really, quite a bit colder than 14 degrees. I think I just get overly worried that it will stress my fishies and somebody told me when I first started fishkeeping to make water changes the same temp as their tank water. I do a 30-40% water change every two weeks, sometimes more often if I think it needs it.
that's why I use the pump I got from Mike's fishing cos it fits to our kitchen mixer, so I can make the water around the same temp, but everyone has their own preferences. But there are other benefits to this pump as I already mentioned and it does cut back the time water changes take with a bucket and jug, which is what I used to use, which was another reason I wanted to buy it, it basically solved all my probs regarding water changes for around $25.