Plumbing in a Dishwasher
PLUMBING IN A DISHWASHER
Plumbing in a dishwasher is no more difficult than plumbing in a washing machine — and in many cases it’s easier. Normally there are less restrictions on how and where you can make the connections. And the dishwasher’s natural location — beside the kitchen sink — means that there are water and drainage supplies conveniently close to hand.
Unlike washing machines, however, most dishwasher ranges include models for building into an existing run of kitchen units. These are designed to fit a standard 600mm (2′) wide base unit, and can be fitted either with a laminate ‘decor’ panel or a false door front to match the kitchen system. Most also have removable plinths and adjustable feet, for easy fitting under a worktop.
If building-in is an important consideration, make sure your chosen model is designed with this in mind. Check too, that the maker of the kitchen units offers laminate panels or door fronts as accessories.
Before you buy any parts, read through the maker’s installation instructions: these are largely the same from model to model, but there may be specific recommendations that have to be followed in order to validate the guarantee.
Water supply Most dishwashers are cold-fill only (or are recommended for such), so you can take the supply from the rising main feeding the sink cold tap.
The easiest method is to fit a washing machine self-cutting connector incorporating a stoptap tee and a standard 3/4" BSP thread for the dishwasher supply hose. Make sure the connector you buy carries water authority approval.
Drainage outlet Break into the sink waste pipe using a 38mm (1-1/2") self-cutting connector, or replace the existing sink trap with a washing machine trap incorporating a hose connection. (Some makers recommend installing a washing machine standpipe, but this isn’t strictly necessary if you take care how you fit the dishwasher drain hose.
If the dishwasher is to be built in, the instructions will give details of what size laminate décor panel or door front to order. décor panels are clipped to the door of the machine using the trim pieces supplied. False doorsto brackets or lugs on the front of the machine. Buy a 600mm (24") length of new plinth panel to match the units if you can’t adapt the old one to fit.
Tools checklist: Screwdriver, adjustable spanner, electric drill and bits,, tape measure.
A typical connection set-up (below), showing the inlet hose supplied via a self-cutting connector and the outlet hose linked to a washing machine trap.