---
title: "How Often to Clean a Range Hood Filter, and How the Hood Tells You"
description: "How often should you clean range hood filter: the maker's own 40-hour and 120-hour alarms, and the three ways its hoods signal them."
url: "https://bertazzonimiami.support/blog/how-often-to-clean-a-range-hood-filter/"
date_modified: "2026-08-27"
Category: "Maintenance & Prevention"
---


# How Often to Clean a Range Hood Filter, and How the Hood Tells You

## How often should you clean range hood filter? Monthly — and the hood counts for you

Ventilation is a fifth of this maker's catalog: **thirty-seven hoods**. It also builds the interval into the appliance, which most makers do not.

## The maker's own numbers

On the KG hoods, published plainly:

- **After 40 hours of use**, the hood enters alarm mode and the first-speed light flashes. That means **wash the mesh grease filters**.- **After 120 hours**, the second-speed light flashes. That means **replace the charcoal filters**, if the hood is running in recirculation.

Both are reset with button combinations pressed together while the motor is off, and the two alarms use different combinations.

Forty hours is about a month in a kitchen that cooks most days. The alarm and the habit agree.

## Three hood families, three different signals

This is the part that is genuinely specific to this make, and it is why a generic hood article is no help to you.

**KG hoods** — the display item flashes, and *what it alternates with* is the message. Alternating with **F**: the grease filters. Alternating with **C and F**: the charcoal filters.

**KPH hoods** — a single key flashes, and **the rate is the message**. About **every two seconds**: wash the grease filters. About **every half second**: replace the active carbon filters. Reset by holding that key for around five seconds until it stops.

**KMC hoods** — the filter saturation alarm is cleared from the **speed-three key**, held for about two seconds with the motor and lights both off. The indicator flashes three times to confirm. The charcoal alarm on these is a separate thing that has to be **switched on** for a hood converted to recirculation, by holding the intensive key.

Check the manual for your own model for the exact keys. What is worth carrying away is that **a flashing hood is almost never a problem** — it is the appliance asking for maintenance.

## Grease filters: wash them

Metal mesh or baffle, designed to be washed, and the dishwasher does it well — hot cycle, on their own, dried completely before they go back.

By hand: hot water and a degreaser, and time in the water rather than effort with a brush.

Note which way round baffle filters came out. They have an orientation and it matters to how they perform.

## Charcoal filters: replace them

The maker is explicit: **active carbon cannot be cleaned or regenerated.** The carbon is consumed by adsorbing what passes through it, and washing it does nothing at all.

Roughly every four months, though how much frying you do changes that considerably.

And they only exist on hoods that **recirculate**. If yours ducts outside, you have no charcoal filters and the charcoal alarm should be switched off — otherwise it will spend years asking you to replace something that is not there.

## Reset it afterwards, or none of this counts

The alarm is a **timer**, not a sensor. It counts hours of operation. It has no way of knowing you washed anything.

A hood flashing at a set of spotless filters is the commonest "my hood is broken" call this site gets, and it is a two-second button press.

## What clean filters will not fix

If the hood **sounds strong and clears nothing**, the filters were never the problem. That is the duct, the damper or the make-up air — a long run, three elbows, a crushed flexible section, or a wall cap whose flaps have seized shut with old grease.

Clean the filters anyway; then read the ducting page rather than buying a motor.

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