It is strongly recommended to always remain in Wudhu, but should someone renew it even though he does not need to?..
From Muhammad bin Musa bin Al-Muttawakil, from Ali bin Al-Hussain Al-Sa’daabady, from Ahmed bin Abi Abdillah Al-Barqy, from Muhammad bin Sinaan, from Al-Muffadhil bin Amr, who said
Imam al-Sadiq (AS) said, ‘He who renews his ablution without [the need to do so to purify] an impurity, Allah renews his repentance without him [needing to] asking for forgiveness.’
الإمامُ الصّادقُ (عَلَيهِ الّسَلامُ): مَن جَدَّدَ وُضوءَهُ لِغَيرِ حَدَثٍ جَدَّدَ اللّهُ تَوبَتَهُ مِن غَيرِ استِغفارٍ
Source: Wasaa’il Al-Shi’a, Al-Hur Al-Aamili, Volume 1, Page 377, Hadith #7 (See Image)
From him, from his father, from Usman Bin Isa, from Sama’at Bin Mahran who said,
‘I was in the presence of Abu Al-Hassan Musa (as), so I Prayed Al-Zohr and Al-Asr in front of him, and was seated in his presence until Al-Magrib presented itself. So he (as) called for the ablution, so he performed the ablution for the Prayer, then said to me: ‘Perform ablution’. So I said, ‘I am upon ablution’. So he (as) said: ‘And I was also upon the ablution, but the one who performs ablution for Al-Magrib, that ablution of his would be an expiation for what has passed from his sins during his night, except for the major sins’.
Source: Al-Mahaasin, Volume 2, Book 1, Page 26, Hadith 27 (See Image)
Although it is not necessary to renew your Wudhu if it has not been broken – Allah (swt) opens his doors of Mercy upon us for doing this simple act, so it is in our best interests. May we all be forgiven our sins.