Christian McArdle wrote:
I recently moved into a ten-year old house. The hot water of the shower
worked fine in summer. However, when the outside temperature begins to
drop down around 30, the hot water in the shower does not seem to work.

I don't know where you live, but it isn't anything like 30C for about 364
days of the year round this way!

Of course around this time of year the temperature is starting to dip
to about 30F in most of the country!