Maximum height under furniture

At 143mm high it won’t go where a lower profile bot will. So that rules out cleaning under beds or couches unless there is clearance.

Error handling (when obstructed, steps, cords, clothing)

It did exceptionally well on avoiding obstructions, cords, clothes etc. So much so that I feel confident that a lot of the pre-preparation suggested above could be let slide. Remember it uses 3D Laser instead of physical bumping so it cannot hurt furniture.


At its highest Turbo mode, it was 55dB and in normal use about 48dB.


Like the LG A9 Stick vacuum, it has a flip open, 600ml dust canister and removable and washable cyclone cone. I really appreciate that the whole unit is washable including the pre-HEPA filter pad, but LG suggests you let it dry for 48 hours.

The HEPA filter is also washable, making this very low maintenance.

LG R9 Master
LG R9 Master

The front full-width brush is removable and can be cleaned but not washed.

The app

The app provides LG ThinQ functions and is not necessary for general cleaning.

It has

LG R9 Master
  • Home Guard to detect motion in an approximate 3-metre arc from, its camera.
  • Home view shows what the vac is seeing
  • Scheduled cleaning
  • Cleaning diary (a log and floor plan)
  • Smart Diagnosis (not tested)
  • Set up push alerts

While Home Guard sounds like a good idea, the image quality is not outstanding.

Voice assistants

It’s easy to add LG ThinQ to Google Assistant and to voice control basic vacuum functions like start cleaning or go home.

GadgetGuy’s take – LG R9 Master robot vac is the best yet – by far

For fear of repeating our earlier review spoiler, it is the first that I would feel comfortable in letting it clean my home while unattended. The next three weeks of use are to test out the remote mapping features and see if there are any foibles – we will then update the review.

For now, my wife and I are very impressed at the speed, efficiency and clean quality. Lucky is welcome in our home.


Now that we have finished our review, we read others to see if there are any issues others have experienced. Indeed, on LG’s website, there is a mix of good and bad reviews. Let me address some of the concerns.

  • Dropping out of the Wi-Fi network. This is not LG’s fault but rather the result of an underpowered router resulting in inadequate network coverage – get a better router.
  • Won’t clean under couches. Valid if the clearance is not at least 150mm
  • Scratched one of the chair legs. Its 3G anti-collision technology means this is a rubbish claim. It does not use bumper technology, so it does not run into things
  • Won’t negotiate 20mm sills – we have tested to 25mm, and it’s excellent and goes where no other robot vac goes
  • Will leave dust behind – we vacuumed the same area immediately after with the LG A9 Master, and it picked up very little extra dust. Its suck power is as efficient as the A9.
  • Cleaned the same room three times (on the first try). It takes time – a few weeks – to learn the room/furniture layout and then this will not happen.
  • Scratched my wooden floor very badly. There is no way the vacuum can scratch the floor as on the Mohs hardness scale plastic is far softer than wood. It is more likely that something like a metal screw was caught in the Power Head and that is a user and maintenance issue – not the vacuum’s fault.
  • A recharge takes hours – yes that is correct and the same for any robot vac. This has a 5200mAh battery and takes about four hours.
  • Resumes cleaning at 2 AM after a charge and wakes the family – use the app’s sleep mode.
  • Patterned or dark rugs can confuse it – sorry the 3D camera does not get confused as its looking parallel and at an angle to the floor – not down at it

To the naysayers, we simply say that if LG R9 Master cannot do it for you – nothing can.

LG R9 Master robot vacuum cleaner is the best yet – by far
Name: LG R9 Master robot vacuum Price (RRP): $1899 but shop around for a deal Manufacturer: LG
Reliable, powerful, unattended cleaningFar mroe advanced than other current robot vacsTerrific battery life and smart turboAmazing 3D obstacle avoidance - no bumping into things
Value for money
Ease of Use
4.6Overall Score
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