Meeting all Your Plumbing, Heating, Cooling & Water Conditioning Needs for 3 Generations in Manheim & Surrounding Communities. Since 1939, Haldeman Mechanical has brought peace of mind to homeowners and business owners in Lancaster, PA. With 24/7 emergency services, monthly maintenance plans, and caring technicians, Haldeman Mechanical is the champion in plumbing and HVAC services for local homeowners and businesses.