iRobot Roomba Plus 4020 Combo

No lab has tested it yet, so it is not in our ranking.

Customer rating ★ 4.2 from 5 reviews at Amazon

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Before you buy, compare it with 2 recommended alternatives

No store here sells this model today, so beside it the highest-scored model with the same kind of station that one does, and the cheapest of the top 10.

Green is the best of these 3, also when they share the lead.

Price and ranking
	This model iRobot Roomba Plus 4020 Combo	Cheapest of the top 10 eufy Omni E25 Best on 2 facts	Highest score here Narwal Freo 20 Best on 4 facts
Lowest price	–	$599Amazon.com best	$1,099Narwal (brand store)
Score	not in our ranking		best
Rank	–	rank 6 of 65 with an all-in-one station	rank 1 of 65 with an all-in-one station
Customer rating	★ 4.2 · 5 reviews	★ 4.4 · 54,077 reviews	★ 4.4 · 59 reviews
Mopping
Mop type	spinning pads	roller mop	roller mop
Mop lift on carpet higher is better	0.3 in (7 mm)	0.4 in (10.5 mm) best	0.4 in (10 mm)
Automatic mop detach	–	no	no
Washes the mop same on all	yes	yes	yes
Hot-air drying	–	yes	yes
Station
Station same on all	all-in-one station	all-in-one station	all-in-one station
Dust bag lasts longer is better	up to 75 days	up to 75 days	up to 120 days best
Plumbing hookup	–	no	–
Brush and obstacles
Anti-tangle brush	–	yes	yes
Obstacle avoidance	–	AI camera	AI camera
Climbs thresholds up to higher is better	0.6 in (16 mm)	0.8 in (21 mm)	1.6 in (40 mm) best
Climbing system for high thresholds	–	no	no
Size, noise and age
Robot height lower is better	4.2 in (10.7 cm)	4.4 in (11.1 cm)	3.7 in (9.5 cm) best
Noise not judged	–	63 dB	–
On the market since	–	December 2024	June 2026

Facts as the maker states them. A dash means the maker does not name it. Each model’s page gives the source of every fact. Noise is the maker’s own figure, so we do not judge it, and a customer rating only counts from 20 reviews.

iRobot Roomba Plus 4020 Combo specifications

The numbers that matter first, then every fact by group. As published by the maker or the store we read it from.

Robot height4.2 in

Climbs thresholds up to0.6 in

Mop lift on carpet0.3 in

Runtime per charge120 min

Suction power7,000 Pa

Consumables: a 2.5 l dust bag in the station, which lasts up to 75 days.

Dimensionsrobot and dock

From the published dimensions. The dock needs a spot 12.4 in wide and 17.7 in deep.

Suction and brushes 2 facts

Suction power Suction in pascal, as the maker measures it. More pascal helps on carpet, but it says little about how well the robot picks grit off a hard floor.: 7,000 Pa
Carpet detection The robot notices when it drives onto a carpet. Most then raise their suction, and a mopping robot lifts its mop or leaves it at the dock.: detects carpet and boosts suction

Mopping 2 facts

Mop type How the mop is built: flat pads, two spinning discs or a roller. Discs press harder on dried-on dirt, a roller rinses itself while it works.: spinning pads
Mop lift on carpet How far the robot lifts the mop when it drives onto a carpet. From about 0.4 in (10 mm) a medium pile stays dry.: 0.3 in (7 mm)

Dock 7 facts

Empties the dust bin The dock empties the robot’s dust bin, usually after every run. You only empty the dock’s bag or bin.: yes
Bagless The dock collects dust in a bin instead of a disposable bag. No bags to buy, but you empty it yourself.: no
Dust bag capacity How much the dust bag in the dock holds.: 2.5 l
Dust bag lasts How long the maker says a dust bag lasts with daily use. With pets or a lot of carpet it is shorter.: up to 75 days
Washes the mop The dock washes the mop for you, so you do not rinse it by hand.: yes
Dries the mop The dock dries the mop afterwards, so it does not sit there wet and start to smell.: yes
Dock size (w × d × h) The width, depth and height of the dock. Measure the spot you have in mind, and leave room for the lid and for the robot driving in.: 12.4 × 17.7 × 18.6 in (31.5 × 45 × 47.2 cm)

Navigation and obstacles 3 facts

Navigation How the robot maps your home and follows that map. Lidar measures with a laser and works in the dark, a camera looks along and recognizes more.: LiDAR turret
Climbs thresholds up to The highest threshold the robot takes, as the maker states it. Measure your own: the step into a bathroom or onto a balcony is often higher.: 0.6 in (16 mm)
Multi-floor maps How many floor plans the robot keeps. With more than one it knows which floor it is on when you carry it up or down the stairs.: 4

Robot 3 facts

Robot height How tall the robot is. It decides whether it fits under your sofa, bed or cabinet.: 4.2 in (10.7 cm)
Robot weight What the robot weighs. It counts most if you carry it up a staircase every day.: 9.1 lb (4.11 kg)
Dust bin in the robot How much dust the robot holds before you empty it. It matters less with a self-emptying dock, which empties the bin after every run.: 295 ml

Battery 1 fact

Runtime per charge How long the robot cleans on one charge, at its quietest setting. After that it recharges and carries on where it stopped.: 120 min

Smart features and warranty 2 facts

Voice assistants Which voice assistants the robot works with, such as Google Assistant or Alexa.: Alexa, Google Assistant, Siri
Home Assistant Whether the robot works with Home Assistant, the home automation software you run yourself. Official means the integration comes with Home Assistant itself, community that volunteers maintain it.: official integration