I am sure in your lease it says what constitutes access for the owner. You gave notice. The plumber is coming on Saturday and if you want to be there you should go. Your lease gives you the right of access after giving notice for inspections, maintenance, or whatever.

If he gives you a hard time you can remind him that uncooperative tenants get higher rent increases than cooperative tenants and really uncooperative tenants pack their bags and go find another place to live.

Part of your tenant selection should be screening for cooperative people who follow the rules. Get rid of those that don't. Give him his 30 day notice (or whatever your state requires) that his lease will not renew and on 12/31/2024 (or whatever the date is) he needs to be completely moved out. Give cleaning instructions as well.

This is one of the reasons you have a security deposit. To make it financially painful for them not to follow the rules.

Why are you giving him a 48 hour notice of you planning to enter his home if the plumber isn't coming for a week?

I would suggest that you accompany the plumber when he does show up. Contracts can be as good as gold, and it appears you are sending them into a hostile work environment.

The notice should state which day(s) you plan to enter. I believe the 48 hours is just the minimum.

Mine are 24 hour notices and I just text or call. I have had a little pushback because of things but unless there will only be a minor child there unattended I go in.

If your tenant is combative then you have an additional problem that you need to remedy right now. Refusal to let me in my place is grounds for eviction. Complaining about rent increases is one thing, but being argumentative about it is the next level.

I do not maintain an adversarial relationship with my tenants. I normally call or text to arrange a convenient time/date for the repairs. The tenant is normally anxious for the repairs and does not insist on 48 hours notice.