Angular 4 Firebase Password Reset Email https://angularfirebase.com/lessons/angular-firebase-authentication-tutorial-email-password-signup/

auth.service.ts

import { Injectable } from '@angular/core';
import * as firebase from 'firebase';
//...omitted

@Injectable()
export class AuthService {
  
  resetPassword(email: string) {
    var auth = firebase.auth();
    return auth.sendPasswordResetEmail(email)
      .then(() => console.log("email sent"))
      .catch((error) => console.log(error))
  }
  
}

reset-password.component.html

<button (click)="resetPassword('hello@angularfirebase.com')">Reset Password</button>

reset-password.component.ts

import { Component } from '@angular/core';
import { AuthService } from "./somewhere/auth.service";

@Component({ 
  // omitted...
})

export class ResetPasswordComponent {
  
   resetPassword(email: string) {
     this.auth.resetPassword(email)
   }

}