[maris oren]

partner opens with 1 h. opponens pass, I have good support of H with 5 H, 14 HCP, 3 S; 3D; 2 C.
What should I bid?

[Cyberyeti]

Most people use 2N as some sort of raise, whether it's to 3 or better or it's game forcing

[fromageGB]

2NT has with many players long been abandoned as natural, and in most places it would probably be safe to bid this and expect partner to assume some sort of support, and unless he gets excited by that you will rebid 4♥. However, if you have any doubt that it will be so interpreted (in a room of acol players?) then don't bid 2NT but bid 4♥ immediately.

2NT is better, if you have agreed that, as this shows a strength hand while 4♥ is usually played as weak and preemptive with 5 hearts. Over 2NT a better than minimum opener will explore slam, but 4♥ tells him to shut up. Search for Jacoby 2NT and discuss it with a regular partner.