Even if your current workplace wants you to drive your head through a wall, remain kind and poised. If you plan to continue your career in the same industry as your past
job, it is imperative to maintain a decent relationship with your previous boss and coworkers (especially if you plan to reference the company on your resume).
Submit a two-weeks’ notice resignation stating your reasons for leaving. Be sure to submit this notice two weeks in advance to provide the company enough time to re-fill
your position. Express your reasonings in a well thought out manner. It’s always best to compliment your boss, the company, and highlight the positives of your experience there.
Here is an article providing multiple resignation templates: https://www.thebalancecareers.com/two-weeks-notice-resignation-letter-sample-2063069.
In the mechanical HVAC and Plumbing industry, the circle is pretty small. Most employers know each other, so receiving a bad reference is very damaging. One bad reference
can be the sole reason you don’t get hired at other companies. Take each day with stride, professionalism, and incredible work ethic.