Whirlpool WDF540PADM dishwasher not heating — Normal and High Temp lights flash 10 times

Hi, I’m Mike, your appliance troubleshooting expert. On many Whirlpool models, the Normal + High Temp flashing in diagnostics indicates the control didn’t see the expected water temperature rise and has disabled the heater (a heater/temperature fault). What’s the full model number, and is the problem only poor drying or is there also no heat during the wash (no steam when you crack the door mid‑cycle)?

When you crack the door about 15–20 minutes into the main wash, do you see/feel noticeable steam and very hot water, or is it just lukewarm?

Are the spray arms spinning with strong pressure and are dishes getting clean, or has overall wash performance also dropped off?

When the cycle ends, does the Sanitized light fail to come on and are the dishes left wet while the cycle otherwise completes normally without beeps or error lights?

Thanks—that helps. Based on your WDF540PADM symptoms (water never gets hot, poorer cleaning, and the Normal + High Temp lights flashing in diagnostics), the control has flagged a “heater disabled/no temperature rise” fault, and the heater is almost certainly not operating.

Most likely causes (in order):

• Heating element open (burned out) — most common when there’s zero heat and cleaning drops.
• High‑limit thermostat (thermal cutoff) open in the heater circuit.
• Loose/burned wiring or connector at the element, high‑limit, or control’s heater relay.
• Control board heater relay failure (less common than the two above, but possible).
• OWI/NTC temperature sensor fault misreporting water temperature, which can disable heat.
• Low fill or weak circulation (inlet valve or wash motor issues) can prevent the expected temp rise and trigger the heater-disable logic, compounding poor cleaning.

What a tech would check:

• Continuity of the heating element and the high‑limit thermostat.
• Whether the control sends power to the heater during a heat call.
• OWI/thermistor readings in diagnostics.
• Proper fill level and strong spray pressure.

Typical repair ranges (parts only):

• Heating element: ~$30–$70
• High‑limit thermostat: ~$20–$40
• OWI sensor: ~$40–$90
• Control board: ~$150–$250 Labor often adds ~$150–$250 depending on area.

Safety note: Live 120 V wiring is present under the dishwasher; avoid testing “live” unless you’re trained. Sharp sheet‑metal edges under the unit.

Would you like step‑by‑step DIY checks to narrow it down (with or without a multimeter), or would you prefer guidance on what to tell a technician?