How to Plumb In a Dishwasher — UK DIY Guide
A dishwasher needs cold water, waste, and a 13A supply. All three usually live under the sink. Here is the UK install method.
Step-by-step method
1. Cold water supply
Fit a 15mm tee off the under-sink cold with a washing-machine-style isolator (blue lever). Connect the dishwasher's blue hose.
2. Waste connection
Fit a sink trap with a dishwasher spigot (McAlpine ST24A). Cut off the seal cap on the spigot, push on the corrugated drain hose, secure with jubilee clip.
3. Electrical supply
13A socket or fused spur. Ideally on a separate spur so kitchen light circuit doesn't trip when it faults.
4. Slide in and level
Feet screw up/down. Level to within 1mm using a spirit level — prevents leaks and door bounce.
5. Test cycle
Run a hot 60°C empty cycle. Check under sink for leaks, check drain flows freely.
Frequently asked questions
Do I need hot water to my dishwasher?+
No — modern dishwashers heat cold internally. Hot water can degrade rinse aid effectiveness.
Can I run dishwasher drain into a standpipe?+
Yes if no sink trap available — same 600–1000mm rule as washing machine.