The short answer
Most Costway portable washers have no heater at all, so a cold wash is not a failure: the machine washes at whatever temperature you fill it with. If the wash is cold, the fill was cold. Establish first whether your machine has a heater, because that single fact decides whether there is anything to repair.
What you are actually seeing
- The wash water is cold on every cycle — Means: on-page
- There is no temperature selection on the control at all — Means: on-page
- A hot setting exists but the water stays cool — Means: on-page
- The wash was warm when filled from the hot tap and cold otherwise — Means: on-page
- Greasy soil is not shifting at all — Means: on-page
- The machine will not run at all — Means: different-fault — Go to: costway-washer-wont-start
- The wash is warm but the result is poor — Means: different-fault — Go to: costway-washer-cleaning-performance
- Body: Match what you see before you take anything apart. The wash water is cold on every cycle. There is no temperature selection on the control at all. A hot setting exists but the water stays cool. The wash was warm when filled from the hot tap and cold otherwise. Greasy soil is not shifting at all. Some near-miss symptoms belong on a different page: The machine will not run at all points at a supply or lid fault, covered on costway-washer-wont-start; The wash is warm but the result is poor points at a load or detergent problem, covered on costway-washer-cleaning-performance.
Causes, ranked for this machine
- The machine has no heater and washes at the fill temperature — Why this rank: First because it is true of most machines in this class, and it resolves the complaint without sending an owner after a part that does not exist
- The fill hose is connected to the cold tap, or the mixer is set to cold — Why this rank: Free to correct, and it is the whole answer on a machine that has no heater
- The hot tap has not been run before filling, so the first water is the cold slug in the line — Why this rank: Common and completely avoidable
- A temperature selection that only chooses which tap the machine draws from — Why this rank: Explains a hot setting that produces cold water when only a cold supply is connected
- A failed heater or thermostat on the minority of models that have one — Why this rank: Last because it applies only to machines that actually have a heater
- Body: Ranked for a portable washer: either a twin-tub with a separate wash tub and spin basket that drains by gravity, or a compact single-tub machine that fills from a tap adapter and drains with a pump. Most likely: The machine has no heater and washes at the fill temperature. First because it is true of most machines in this class, and it resolves the complaint without sending an owner after a part that does not exist. Next most likely: The fill hose is connected to the cold tap, or the mixer is set to cold. Free to correct, and it is the whole answer on a machine that has no heater. Third: The hot tap has not been run before filling, so the first water is the cold slug in the line. Common and completely avoidable. Fourth: A temperature selection that only chooses which tap the machine draws from. Explains a hot setting that produces cold water when only a cold supply is connected. Fifth: A failed heater or thermostat on the minority of models that have one. Last because it applies only to machines that actually have a heater.
What to check, in order
- Check the rating plate and the control to establish whether the machine has a heater at all
- Run the hot tap until it is hot before filling
- Connect to the hot tap, or set a mixer to hot, before starting
- Feel the water in the tub during the wash rather than judging by the result
- Body: Each check rules out the causes above it. First, check the rating plate and the control to establish whether the machine has a heater at all. Second, run the hot tap until it is hot before filling. Third, connect to the hot tap, or set a mixer to hot, before starting. Fourth, feel the water in the tub during the wash rather than judging by the result.
Checks you can safely make yourself
- Look at the control and the rating plate and establish whether your machine has a heater or simply a temperature selection — Tools: torch — Time estimate: a few minutes
- Run the hot tap until the water is hot to the hand, then fill the machine straight away — Tools: none — Time estimate: a few minutes
- Connect the fill hose to the hot tap, or set a mixer tap to hot, and fill the tub — Tools: none — Time estimate: a few minutes
- Feel the water in the tub shortly after filling to confirm what temperature the machine actually received — Tools: none — Time estimate: a few minutes
- Wash the same load once with a cold fill and once with a warm fill and compare the results — Tools: notepad — Time estimate: two cycles
- Body: Checks an owner can make with the machine unplugged or by watching a short cycle. Step one: Look at the control and the rating plate and establish whether your machine has a heater or simply a temperature selection. Tools: torch. Time: a few minutes. Step two: Run the hot tap until the water is hot to the hand, then fill the machine straight away. Tools: none. Time: a few minutes. Step three: Connect the fill hose to the hot tap, or set a mixer tap to hot, and fill the tub. Tools: none. Time: a few minutes. Step four: Feel the water in the tub shortly after filling to confirm what temperature the machine actually received. Tools: none. Time: a few minutes. Step five: Wash the same load once with a cold fill and once with a warm fill and compare the results. Tools: notepad. Time: two cycles.
Safety first
Safety
Unplug the machine before reaching into a tub, and do not fill with boiling water: use hot tap water at most. Carrying hot water to a machine is a scald risk, so use a hose rather than a bucket where possible. Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. unplug-before-service
Where the owner fix ends
Call for a warranty claim or a technician only where your machine genuinely has a heater, the fill is proven hot and the water still does not warm. On the majority of machines in this class there is no heater to fail, and the answer is the tap rather than a repair.
Nearest pages of the same kind
Generalized information
This page is generalized across the Costway portable washer line. Twin-tub machines and compact single-tub machines share the ranking above but almost none of their parts, and this page does not cover a specific model or control revision. Family- and model-specific pages, where they exist, are linked below.
Links: - [Common COSTWAY Washer Problems](/blog/costway-washer-problems) - [COSTWAY Washer: Abnormal Noise or Vibration](/blog/costway-washer-abnormal-noise) - [COSTWAY Washer: Does Not Clean or Dry](/blog/costway-washer-cleaning-performance) - [COSTWAY Washer: Controls, Display or Error Code](/blog/costway-washer-control-fault)
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
