You open the dishwasher at the end of a cycle and find standing water in the bottom. Dishes are still dirty. The smell is unpleasant. Your dishwasher has a drain failure.
The good news: dishwasher drain failures are among the most affordable and fastest repairs we perform in Concord, NH. In many cases, the fix is even a DIY task — and we will tell you exactly what to check before calling a technician.
The 5 Most Common Causes
1. Clogged Filter or Drain Basket — Check This First
Check Before Calling
Modern dishwashers have a manual filter at the bottom of the tub that catches food debris. When this filter is not cleaned regularly — every 2–4 weeks for heavy use — it clogs completely and prevents water from draining.
DIY check: Remove the bottom rack. Find the cylindrical filter at the bottom (usually twist-lock). Remove it, rinse it under running water with a soft brush, reinstall it, and run a short cycle. If the dishwasher drains, the filter was the problem — no technician needed.
This is the cause in approximately 30% of dishwasher not-draining calls we receive in Concord, NH. A clean filter is the simplest, most overlooked dishwasher maintenance task. Brands with filter systems: Bosch, Samsung, KitchenAid, GE.
2. Failed Drain Pump
Most Common Professional Repair
The drain pump forces water out of the dishwasher tub through the drain hose. When the pump motor fails — or when a small piece of broken glass or debris jams the pump impeller — the dishwasher cannot drain.
Signs of a failed drain pump include standing water at the end of every cycle, an error code (E24 on Bosch, 7E on Samsung), or a buzzing/grinding sound during the drain phase.
Repair cost: $120–$250 for drain pump replacement. We carry drain pumps for all major dishwasher brands on our service vans. Same-day repair available in Concord, NH. See our full dishwasher repair page.
3. Blocked or Kinked Drain Hose
DIY Check Possible
The drain hose connects the drain pump to either the garbage disposal or the sink drain. If this hose is kinked, has slipped off its connection, or has a food clog inside, water cannot exit the dishwasher.
DIY check: Pull the dishwasher out slightly and inspect the drain hose at the back for kinks. Also check where the hose connects — it should have a high loop above the drain connection to prevent backflow. If the hose looks fine, the issue is likely the drain pump or the connection point at the garbage disposal.
Repair cost if professional needed: $80–$150 for drain hose replacement or reconnection.
4. Garbage Disposal Connection Issue
Often Overlooked
Most dishwashers drain through the garbage disposal. Two issues can prevent draining at this connection point:
- Clogged disposal: If the disposal itself is jammed or clogged, it backs up into the dishwasher drain. See our garbage disposal repair page.
- Knockout plug not removed: On newly installed disposals, a plastic knockout plug inside the dishwasher inlet must be removed. If it was not removed, the dishwasher cannot drain at all. This is a 2-minute fix with a screwdriver — but most homeowners have no idea it exists.
If your dishwasher stopped draining after a new garbage disposal was installed, this is almost certainly the cause.
5. Check Valve or Air Gap Failure
Less Common
The check valve (or flapper valve) at the drain pump prevents water from flowing back into the dishwasher after draining. If it gets stuck closed, water cannot drain at all. If it gets stuck open, dirty water flows back after each drain cycle — leaving residual water that appears as standing water.
Some installations also use an air gap — a chrome fitting on the countertop near the sink — to prevent backflow. A clogged air gap can prevent dishwasher draining entirely. Inspect it and remove any debris blocking the ports.
Repair cost for check valve: $90–$170. Usually combined with drain pump inspection since access requires the same disassembly steps.
When to Call a Professional in Concord, NH
If you have checked the easy DIY items above and the problem persists, it is time to call a licensed technician. Our Concord, NH dishwasher repair technicians provide same-day service throughout Merrimack County — including Bow, Hooksett, Pembroke, and all surrounding towns.
We give you a flat-rate quote before starting any work, back every repair with a 90-day parts and labor warranty, and will always give you an honest recommendation on whether repair or replacement makes more sense for your specific appliance. See our full Dishwasher Repair page for complete information on what we fix and what it costs.
Frequently Asked Questions
Sometimes, yes. Always check the filter first — it is the most common cause and takes 2 minutes to clean. Also check for a kinked drain hose and inspect the garbage disposal connection. If these checks do not resolve the issue, call us for a same-day diagnosis in Concord, NH.
Common drain error codes: E24 or E25 (Bosch) = drain pump or hose. 7E (Samsung) = drain issue. F2 or E2 (Whirlpool/Maytag) = drain failure. We diagnose and fix all dishwasher error codes in Concord, NH — call (603) 515-5450.
Filter cleaning is free DIY. Professional dishwasher drain repairs in Concord, NH typically cost $100–$250 for drain pump replacement or $80–$150 for hose issues. We provide a flat-rate quote before starting any work.
