Get the exact manual before the quote
Send the installer the full model number and installation document, not just the retailer description. Ask whether the existing connections meet that model’s requirements and which changes are included in the quote. This guide is a purchase checklist, not wiring or plumbing instructions.
Check whether delivery includes unpacking, moving the appliance into the kitchen, installation, a test run and removal of the old machine. Retailers can treat those as separate services. Agree on the route, stairs and access before the truck arrives.
Clarify the connection parts
A power cord, drain hose, water-supply hose and hardwire junction box are different items. The Bosch SHP65DM5N specification, for example, lists a power cord and drain hose but treats the supply kit and hardwire junction box as optional. Do not assume another brand includes the same pack.
Have the installer identify approved fittings and hose lengths. Avoid buying a generic kit solely because its listing says universal. Drain arrangements, air-gap requirements and electrical work depend on the appliance instructions and local requirements.
Protect fit and access
The machine must be level, secured and able to open without interference. A custom panel or automatic opening door needs particular attention. Keep the shutoff and service access practical rather than sealing the machine into cabinetry.
Do not trim a hose, modify a power connection or bypass a safety feature to make an unsuitable setup fit. Discuss any mismatched supply or cabinet condition with the qualified installer before accepting the appliance.
Finish with a handover
Ask for a demonstration of the controls, filter removal and the first-run checks specified by the manufacturer. Inspect for shipping damage and visible leaks, retain the manual and installation invoice, and record the serial number. Clarify who to contact if a problem appears after the installer leaves.