Avoiding his anger

How do you grey rock your narc spouse when he tries picking a fight with you for no reason? My fiance tends to be really hyper vigilant with my voice tones whether if I’m annoyed about something or getting frustrated about something. My fiance matches it by getting snippy or angry at me as if I was mad at him, when I was just annoyed about something else that has nothing to do with him.

So I noticed sometimes when he gets frustrated about something being stuck or something at home isn’t working, he cusses and get visibly annoyed, then I’ll respond “oh, that’s okay, we can get a new one,” or “we can call the manufacturer and see what they say”. He doesn’t seem to like hearing solutions to a problem. I’m the kind of person that analyzes the problem, tries different ways to fix it before deciding yeah it’s broken, time for a new one. My fiance just prefers to have a solution right now or cusses the hell out of it and get angry, which is what I don’t want our kids copying that behavior when a problem approaches.

Why are narcs so angry at everything? Like take a step back and think before getting angry at nothing. I don’t like responding to anger, so I tend to be nonchalant and offer a solution and if he doesn’t want to hear it, I walk away. Is this a good way to tell him that he’s doing too much and just need to learn how to be a better communicator and thinker?