Service
Dishwasher Installation
Connecting dishwashers, including the high loop or air gap that stops drain water siphoning back and the shutoff that makes future work possible.
- Licensed and insured
- Price agreed before work
- A plumber who works your area
The knockout plug
If a new dishwasher will not drain, check this before anything else.
Garbage disposals ship with a plug moulded inside the dishwasher inlet, so the unit can be used in a kitchen with no dishwasher. It has to be knocked out before a dishwasher drain hose is connected.
Connect to a plugged inlet and the machine cannot discharge. It fills, fails to drain, throws an error, and the fault gets blamed on the dishwasher.
It takes seconds to remove at the right moment. Afterwards it means disconnecting the hose to reach it. It is the most common single fault on a new installation and it is entirely avoidable.
Stopping water going the wrong way
The drain connection has to prevent waste water being siphoned back into the machine, and there are two accepted ways.
An air gap. A fitting, usually mounted on the worktop, that physically breaks the drain line so nothing can be drawn backwards. Required in some jurisdictions.
A high loop. The drain hose is secured up under the worktop, above the level of the sink drain, before dropping to its connection. Accepted in many places and simpler.
What is not acceptable is a hose running flat from the machine to the drain, because a sink full of dirty water and a change in pressure can pull that water into the dishwasher.
Which one applies to you is a code question, and it is worth doing whichever it is properly rather than relying on the hose happening to sit high enough.
Does this sound familiar?
Problems this service solves
- Fitting a dishwasher where there has never been one
- Replacing a machine with different connections
- A dishwasher that will not drain properly
- No shutoff valve on the dishwasher supply
- A new machine connected to a disposal that still has its plug in
Signs you need dishwasher installation
If more than one of these is true, the problem is usually past the point a plunger or a store-bought cleaner will fix.
- A new dishwasher is being installed
- The old machine left standing water in the base
- There is no isolating valve on the supply
- The kitchen is being refitted
What to expect
How the visit works
Check supply, drain and space
A hot supply take-off, a drain connection and the cabinet opening all have to work together before the machine is unpacked.
Fit an isolating valve
A dedicated shutoff on the dishwasher supply means future work does not involve isolating the whole kitchen.
Fit an air gap or a high loop
The drain hose must rise high enough, or pass through an air gap, so waste water cannot siphon back into the machine.
Check the disposal inlet
If the drain connects to a disposal, the knockout plug has to come out first. A machine connected to a plugged inlet cannot drain at all.
What's included
What you get on every job, whoever we send.
- A dedicated isolating valve on the supply
- Air gap or high loop fitted, not assumed
- The disposal knockout plug checked before connection
- Run through a full cycle before the job is finished
Questions
Dishwasher Installation questions
What is an air gap and do I need one?
It is a fitting that breaks the drain line so waste water can never be drawn back into the dishwasher. Some jurisdictions require one; others accept a high loop, where the drain hose is secured up under the worktop before dropping to the connection. Either way something has to prevent back-siphonage, because without it dirty water from the sink drain can be pulled into the machine. Which is acceptable depends on local code.
My new dishwasher will not drain. What is the most likely cause?
The knockout plug in the garbage disposal, if the drain connects there. Disposals ship with a plug inside the dishwasher inlet so the unit can be used without one, and it has to be removed before a dishwasher hose is attached. Connect to a plugged inlet and the machine cannot discharge at all. It is the single most common fault on a new installation and it is easy to check.
Does a dishwasher need its own shutoff valve?
It should have one, and many installations do not. Without it, any work on the machine, or any leak from it, means shutting off the kitchen supply or the whole house. A dedicated isolating valve on the take-off costs very little at installation and makes every future repair or replacement straightforward. It is the kind of thing that is trivial now and irritating for the next twenty years if it is left out.
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Get it fixed
Dishwasher Installation, handled locally
Call with your ZIP code and what you are seeing. We route you to a licensed plumber in your area who does dishwasher installation every week.
- Licensed and insured
- Answered 24/7
- Price before work