Error code · Dishwasher

Monogram ZBD9900 Dishwasher Code HEAVY Light Flashing: too much water inside the tub

Medium · inspection needed

Code: HEAVY Light Flashing
Appliance: Dishwasher
Brand: Monogram
Warranty: 30-day workmanship

What HEAVY Light Flashing means

The ZBD9900 series of Monogram top-control dishwashers, including the ZBD9900RII, flashes the HEAVY light for an overfill. The control believes there is too much water in the tub because the pressure sensor or the float switch was activated. If the water is not pumped down within 60 seconds, the program stops and the drain pump runs. The owner sees the HEAVY light flashing and a cycle that has halted. This meaning is confirmed for the ZBD9900 series only.

Common causes of HEAVY Light Flashing

Drain pump and a blocked drain hose
Pressure sensor or float switch reading
Inlet valve letting water through
Flow meter and wiring
Filter and sump clogged with debris

✓ One safe check you can try

1. Open the door carefully and look for standing water in the tub. 2. Clean the filter and check that nothing blocks the drain. 3. Check that the drain hose under the sink has no kink. 4. Close the door and start a short cycle. 5. Turn the water supply valve off at the sink if the light returns, and call us.

! Why to stop there

The owner can clear a clogged drain, but not a valve that leaks through
We test the float switch and pressure sensor against the real water level
We separate a pump problem from an inlet valve that keeps filling

Opening a panel yourself does not automatically cancel a manufacturer warranty, but it can cause accidental damage, and some manufacturers set their own service conditions. Check your warranty terms, or ask us, before deciding.

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Other Dishwasher codes

START/RESET Light FlashingMonogram ZBD6800 Dishwasher Code START/RESET Light Flashing: cycle canceled, tub draining AUTO Light FlashingMonogram ZBD9900 Dishwasher Code AUTO Light Flashing: water is not heating up NORMAL Light FlashingMonogram ZBD9900 Dishwasher Code NORMAL Light Flashing: thermistor reading out of range LIGHT Light FlashingMonogram ZBD9900 Dishwasher Code LIGHT Light Flashing: the tub is not filling SPEED Light FlashingMonogram ZBD9900 Dishwasher Code SPEED Light Flashing: inlet valve leaking through RINSE Light FlashingMonogram ZBD9900 Dishwasher Code RINSE Light Flashing: pressure sensor signal reads high AUTO + HEAVY Lights FlashingMonogram ZBD9900 Dishwasher Code AUTO + HEAVY Lights Flashing: water will not drain AUTO + SPEED Lights FlashingMonogram ZBD9900 Dishwasher Code AUTO + SPEED Lights Flashing: turbidity sensor reading uncertain

HEAVY Light FlashingHEAVY Light Flashing questions

Is the dishwasher going to flood my kitchen?

The control stops the program and runs the pump to prevent that. If you see water on the floor, close the supply valve and keep the unit unplugged until we inspect it.

Why does it stop on its own?

The control sees more water than the program allows. After 60 seconds without draining it halts the cycle and pumps out, which protects the tub and the floor.

Can a clogged filter cause this?

It can slow the drain enough to trigger the reading. If cleaning the filter does not stop the flashing, the cause is more likely the pump, the hose or the inlet valve.

Book a visit

Still seeing HEAVY Light Flashing?

A technician diagnoses it on site and gives you the price in writing before any work starts.

(713) 955-0955