The answer, before the detail
Short answer: a blockage, not a breakdown. Start with the drain hose crushed behind the machine on this machine. A pump that has actually failed is the least common cause here and the only one that needs a technician.
What you observe
- The cycle seems to run much longer than it used to — Machines that cannot drain often extend the cycle while they try again, so a long cycle can be the first sign.
- Nothing at all happens during the drain phase — complete silence — Silence where there should be a pump points at the electrical side rather than a blockage.
- An inch or so of water left in the bottom at the end of every cycle — The classic signature. A small amount of clean water in the sump is normal on some machines; a standing pool is not.
- NEAR MISS — water is escaping onto the floor — Water outside the machine is a leak, and that page comes first. Deal with the leak before the drainage complaint it may be causing.
Causes, most likely first on a Koldfront dishwasher
- The drain hose crushed behind the machine — The drain hose has to rise before it falls — either to a high loop under the worktop or to an air gap — so waste water cannot run back into the tub. When that rise is lost, or the hose is crushed behind the machine, the water either will not leave or returns as soon as it has left. Ranked ahead of the rest since it is both the likeliest and the only one that can be settled before anything is taken apart. The mechanism in a compact unit is sized exactly for its rated load, so overloading it is the first cause and not the last.
- The sink waste spigot blocked with debris — The connection is under the sink and takes minutes to inspect, which is why it belongs above anything requiring the machine to be moved. Second, because it produces the same complaint from the other side and is still an owner-side check.
- A sump filled with what came off the plates — A dishwasher recirculates its water many times during a cycle, so the filter is doing its job constantly rather than once. It loads faster than owners expect and it is the first restriction water meets on the way out. It ranks here because it is genuinely less common, not because it matters less when it happens.
- An impeller stopped by something it swallowed — The distinction that matters here is between a jam and a failure. A pump that hums is powered and obstructed; a pump that is silent when it should run is an electrical fault, and that is a technician's diagnosis. Bottom of the order, because reaching it means the three likelier answers were already wrong.
What to check first, second, third
- Open the cupboard under the sink and follow the hose from the machine to the waste — Look for a kink, a crush point, and whether the hose rises before it drops. Do this first: it settles the likeliest cause before any tool comes out.
- Disconnect the hose at the waste spigot over a bowl and look into the opening — Grease and debris build a ring at that fitting that closes it down gradually. Second, once the first check is clean.
- Scoop the standing water out and look into the sump under the filter — Glass, labels and fruit stones collect there and go unnoticed while the filter is in place. Only worth doing once the two above are ruled out.
What you can do yourself
- Ease the machine forward enough to free a trapped hose — Do it slowly, with the door shut, and watch the supply line as you move it.
About 25 min
- Run the sink tap and the disposer to confirm the waste runs freely — A sink that drains slowly will not accept a dishwasher discharge either.
About 10 min
- Remove the filter stack, rinse it under a hot tap with a brush, and refit it locked home — A filter left a quarter turn short of home lets debris bypass it straight into the pump.
Tools: washing-up brush, clothAbout 20 min
- STOP once the checks above are clean and the fault remains — A clean sweep of the owner-side causes is itself a useful result: it tells the technician where not to look.
Read this before you start
Safety
Turn the power off at the wall before any panel comes off or a hand goes into the sump. Never tape or defeat the door latch to make the machine run with the door open: that interlock is the only thing that stops a tub of near-boiling water being sprayed into the kitchen.
When this becomes a service call
Call once the filter, the sump, the hose and the waste connection are clean and water still stands in the tub. Call immediately if the pump is silent when it should run: that is an electrical fault, and the next step is a meter rather than a cloth.
Pages next to this one
What is not on this page
This page is deliberately generalized across the Koldfront dishwashers it covers. It does not carry model-specific wiring, torque values or component resistance figures — those belong on the page for your family, and that page takes precedence where it exists.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
