Siemens dishwasher not draining

What is actually happening

A dishwasher drains through a filter, a pump, and then a hose that usually loops up and into the sink waste. Standing water almost always means a blockage in that path rather than a failed part — food debris in the filter and a blocked sink trap between them account for most of it. The one to check first is whether a new sink or waste disposal has been fitted, because the blanking plug in a new waste spigot is a classic.

The Siemens fault codes that point at this

A Siemens dishwasher will usually tell you what it thinks is wrong before anyone opens it up. These are the codes we hold for this make that relate to not draining:

• E20 — The dishwasher has found an electrical fault in the main wash pump — the motor that pushes water round the spray arms — and has stopped rather than run it.
• E21 — The main wash pump that pushes water up to the spray arms is jammed or can't move water properly, so the machine has halted rather than run a wash with no spray.
• E23 — The dishwasher has lost the electrical signal it expects from the drain pump, so it won't carry on with the cycle.
• E24 — The water isn't leaving the machine fast enough, so the dishwasher has stopped and flagged a drain problem.
• E25 — The dishwasher can't get the water out, and the machine has stopped because the drain pump isn't shifting it.

If yours is showing one of those, that is a much shorter conversation than a general fault — tell us the code when you book and the engineer can often carry the part.

The usual causes on a Siemens dishwasher

• A clogged filter and sump at the bottom of the machine
• A blocked or kinked drain hose, or a blocked sink trap where it connects
• A blanking plug left in the sink waste spigot after a new sink or disposal unit was fitted
• A failed drain pump, or one jammed with a piece of glass or a label
• A drain hose fitted without a high loop, letting waste water siphon back

What you can safely check yourself

1. Bail out the standing water, then lift out the filter assembly and clean it thoroughly
2. Check the sump underneath the filter for glass, labels and debris
3. Check the sink trap the dishwasher drains into — clearing that alone fixes a good share of these
4. If a sink or waste disposal was fitted recently, check the blanking plug was knocked out of the spigot

Common questions

Why is my Siemens dishwasher not draining?

The cycle ends with dirty water standing in the bottom of the machine. A dishwasher drains through a filter, a pump, and then a hose that usually loops up and into the sink waste. Standing water almost always means a blockage in that path rather than a failed part — food debris in the filter and a blocked sink trap between them account for most of it. The one to check first is whether a new sink or waste disposal has been fitted, because the blanking plug in a new waste spigot is a classic.

Can I fix a Siemens dishwasher not draining myself?

Bail out the standing water, then lift out the filter assembly and clean it thoroughly. Check the sump underneath the filter for glass, labels and debris. Check the sink trap the dishwasher drains into — clearing that alone fixes a good share of these. If a sink or waste disposal was fitted recently, check the blanking plug was knocked out of the spigot. Those checks fix it more often than not.

What Siemens error codes mean not draining?

Siemens dishwashers report this through their own fault codes. The ones that point at not draining are E20, E21, E23, E24, E25. If your machine is showing one of those, that narrows it down considerably — each has its own guide on this site.

How much does a Siemens dishwasher repair cost?

£66 including VAT for an engineer to come out and diagnose it, or £84 in total including VAT if it is put right on the visit and no parts are needed. Any parts needed are quoted on site before we fit them — you decide. Every repair carries a 90-day workmanship guarantee.

Other Siemens dishwasher faults

• dishwasher will not switch on
• dishwasher not cleaning the dishes
• dishwasher not drying the dishes
• dishwasher leaking
• dishwasher not heating the water
• dishwasher lights flashing

Repairs we cover near you

• Dishwasher Repairs — what we charge and how it works
• Dishwasher Repairs in Nottingham
• Dishwasher Repairs in Arnold
• Dishwasher Repairs in Beeston
• Dishwasher Repairs in West Bridgford

Written by the engineers at ASAP Repairs from our own repair notes. See also our general guide to dishwashers not draining and our Siemens repairs page.