掛かる and 掛ける has so very many meanings and uses, including 時間が掛かる、電話を掛ける、絵を掛ける. There is a whole list of meanings for it in my dictionary. And they are all daily used expressions. I was just wondering the reason behind this 1 kanji having so many meanings and if someone has found it strange.

Is there some other kanji having so many meanings for the same reading?

Another kanji that has quite a few thingss attached to it would be 気、 including 気にする、気になる and 気づく. But here all the expressions/words do not have the same reading. If there is a real thread on this forum with such kanji that would be great.

Common expressions are the ones most likely to be irregular verbs in western languages, I'm sure something is similar at work.

Anyway, I just treat each expression as a different vocabulary word, and create an entry for
気がする or 鍵を掛ける in my anki deck. (Similarly those two expressions have 'expression' entries in EDICT, and are extremely likely if not certain to show up as sub-entries or expression entries with their own definitions in regular dictionaries.)

It doesn't have anything to do with the kanji, it's the word かける (and かかる) that has a lot of meanings. It's pretty common to see it written in hiragana anyway.

Any language has words that have tons of meanings -- look up "get", "set", and "run" in an English (E-E) dictionary sometime.

Well you are right about English but in Japanese where we have hava different kanji for slightly different meaning (e.g 計る　測る　量る which have a different application even though all mean "to measure"), inspite of that I have come across this 1 kanji from which we are getting　かかる and かける, and it has a really long list of meanings. This is what appears out of place to me you see.

かける and かかる are yamato words. The kanji is applied after the fact.

Starting to use a kanji for the words doesn't remove the extended meanings, nor for that matter stop new extended meanings from being added. It's just the kanji used to spell that word.

You need to stop thinking about what meaning 'kanji' have. Kanji don't have 'a meaning'. They are used to spell words. Words have meaning. We say that a kanji has a 'meaning' of the words that it's closely associated with purely as a mnemonic device, or we say a kanji has a 'meaning' based on the word it was designed to spell (or maybe even be a drawing of) in ancient Chinese. Kanji are not, however, limited to being used in ancient chinese and/or a single common Japanese word with a single simple definition, and the sooner you stop expecting that the easier your life will be.

Right. You can't let yourself depend on kanji to understand the words, because then you won't understand them in speech, or when the word is written with hiragana or non-standard kanji use.

I have understood this topic, thanks.