Asko · Dishwasher

40

Heater Fault

Severity

Medium

Your Asko Dishwasher stopped working and is showing error 40, which corresponds to a fault called "Heater Fault". This is one of the most searched error codes for this appliance — you are not alone, and there is a clear fix.

Owner's Summary

Your Asko dishwasher is not heating the wash water. Asko machines use a flow-through heater — a different design from conventional element heaters. Repair can be more expensive than on budget brands, but the machines typically last 20+ years.

Symptoms

Asko dishwasher not heating water, cold wash results, fault code 40

Common Causes

Failed heating element
Open NTC thermistor
Heater relay failure on PCB
Wiring fault in heater circuit

How to Fix

1 Test heating element continuity
2 Test NTC thermistor resistance at room temperature
3 Inspect heater wiring for burn damage
4 Replace element if open circuit
5 Replace PCB if all components test within spec

Tools You'll Need

Multimeter Flashlight

These are simple, low-risk fixes most homeowners can do with tools already in a basic toolbox.

Technical Explanation

Asko uses an instantaneous flow-through heater rather than a sump-mounted element. Code 40 is triggered when the NTC thermistor at the heater outlet does not confirm the expected temperature rise within the heating phase. This can indicate heater failure, thermistor failure, or PCB relay fault.

Is It Safe to Keep Using?

No safety risk. Fix within a week.

Technician's Pro Tip

Asko flow-through heaters are more expensive than conventional dishwasher elements but rarely fail mechanically. In most code 40 cases, the NTC thermistor downstream of the heater has failed — test the thermistor first before condemning the heater assembly.

Related Codes

E1 — Samsung Dishwasher

Water Supply Error

High

E2 — Samsung Dishwasher

Water Temperature Too High

Medium

E3 — Samsung Dishwasher

Water Not Heating

Medium

Frequently Asked Questions

What does error code 40 mean on a Asko Dishwasher?

Code 40 on a Asko Dishwasher indicates "Heater Fault." In practice, the most common trigger is failed heating element. Severity is rated medium, and typical repair costs range from $30 to $350.

Can I fix 40 myself, or do I need a technician?

Many cases of 40 can be resolved without a technician. The first step to try: test heating element continuity. If that doesn't clear the code, work through the remaining steps in the "How to Fix" section above before assuming a part needs replacing.

Is it safe to keep using my dishwasher with code 40 showing?

No safety risk. Fix within a week.

How much does it cost to repair 40 on a Asko Dishwasher?

Repair costs for code 40 typically range from $30 to $350. Heating element: $60–$200; NTC thermistor: $20–$60; PCB: $120–$350. Costs on the low end usually reflect a DIY fix with no parts required, while the high end reflects a part replacement plus professional labor.

Estimated Repair Cost USD

$30 – $350

Heating element: $60–$200; NTC thermistor: $20–$60; PCB: $120–$350