A two-digit code defined by IEC standard 60529 that rates a device's resistance to solid particles (first digit, 0–6) and water (second digit, 0–9). 'IPX5' means the first digit is not rated (X) and the second digit is 5 (water jets). 'IP66' means dust-tight (6) and powerful water jets (6).
Decoding IP Ratings for Robot Mowers
Most robot mowers carry an IPX5 or IPX6 rating. The "X" in IPX5 means the manufacturer did not test or certify dust ingress protection — it does not mean "maximum dust protection." The second digit (5 or 6) describes water resistance under very specific laboratory conditions.
| Rating | Lab Test Conditions | Real-World Equivalent | Common Mowers |
|---|---|---|---|
| IPX4 | Splashing water from any direction | Light rain, sprinkler overspray | Budget Worx/Gardena models |
| IPX5 | 6.3mm nozzle, 12.5 L/min at 3m | Standard garden hose (low setting) | Husqvarna 430X, Segway Navimow |
| IPX6 | 12.5mm nozzle, 100 L/min at 3m | Strong garden hose (full flow) | Mammotion LUBA 2, Husqvarna 450XH |
| IP65 | Dust-tight + water jets (6.3mm) | All weather + gentle rinse | Select commercial models |
| IP66 | Dust-tight + powerful water jets | All weather + strong rinse | Ecovacs GOAT, professional models |
Where the "Self-Cleaning" Myth Comes From
Some mower marketing materials suggest that the mower can be "easily cleaned with a garden hose." This statement is technically true under specific conditions — but many owners interpret it as permission to use a pressure washer setting or direct a spray into every crevice. The result is water ingress through:
- Charging contacts: The exposed metal contacts on the bottom of the mower are designed for electrical connection, not water sealing. Direct water spray can cause corrosion and charging failures.
- Button seals and display membranes: The rubber seals around buttons and LCD/LED displays are rated for rain-angle water, not direct upward spray when the mower is flipped over.
- Blade disc bearings: While the blade motor is sealed, the disc bearing can admit water under pressure, leading to rust and eventual bearing failure.
- Ventilation slots: Mowers have ventilation openings for motor cooling. These are designed to reject rain but not directed water jets.
What a Pressure Washer Actually Does
A consumer pressure washer operates at 1,500–2,000 PSI (103–138 bar). The IPX6 test uses approximately 14.5 PSI (1 bar). That means a pressure washer delivers 100–140x the pressure that the mower was tested to resist. At these pressures, water penetrates seals that are perfectly adequate for rain and garden hoses.
Using a pressure washer on a robot mower is the single most common cause of water damage claims — and it is almost always denied under warranty because it constitutes misuse.
The Correct Cleaning Method
Weekly Routine (2 minutes)
- Flip the mower onto its back on a soft surface (grass or towel).
- Brush off loose grass clippings with a soft bristle brush or hand broom.
- Wipe the top cover and sensors with a damp cloth.
- Check blade condition — rotate each blade to verify free movement.
Monthly Deep Clean (10 minutes)
- Flip mower onto its back.
- Use a plastic or wooden scraper (not metal) to remove caked grass from the undercarriage and blade disc housing.
- If needed, use a garden hose on the lowest pressure setting, spraying the undercarriage from 30cm distance. Keep spray moving — do not focus on any single point.
- Never spray upward into the mower body. Keep the mower inverted so water drains away from electronics.
- Dry charging contacts with a clean cloth before placing back on the dock.
- Use compressed air (10–15 PSI) to blow debris from ventilation slots if available.
Mower IP Ratings by Brand
| Mower | IP Rating | Garden Hose Safe? | Pressure Washer? |
|---|---|---|---|
| Mammotion LUBA 2 AWD | IPX6 | Yes — low pressure, undercarriage only | Never |
| Husqvarna 450XH | IPX5 | Yes — gentle spray only | Never |
| Segway Navimow X350 | IPX5 | Yes — gentle spray only | Never |
| Ecovacs GOAT A3000 | IP66 | Yes — moderate pressure acceptable | Never |
| Worx Landroid M | IPX5 | Yes — gentle spray only | Never |
Frequently Asked Questions
It depends on the IP rating. IPX5 and IPX6 mowers can handle low-pressure water jets from a standard garden hose nozzle. However, high-pressure settings, direct spray into charging ports or ventilation gaps, and pressure washers should always be avoided — even on IP66-rated mowers.
IPX5 protects against "water jets from any direction" at 12.5 liters per minute from a 6.3mm nozzle at 3 meters distance. This simulates rain and light garden hose spray — NOT a pressure washer, which delivers water at 3-10x the pressure and flow rate of IPX5 testing conditions.
Using a pressure washer or submerging the mower will void most warranties if it causes water damage. Light rinsing with a standard garden hose at low pressure is generally acceptable for IPX5/IPX6 models, but always check your specific manufacturer's cleaning guidelines.
For routine cleaning: (1) brush off loose grass with a soft bristle brush, (2) wipe surfaces with a damp cloth, (3) use a wooden or plastic scraper for caked grass on the undercarriage. For deep cleaning: use a low-pressure garden hose spray on the undercarriage only, keeping the mower upside down so water drains away from electronics.
Every 1–2 weeks during active mowing season. Caked grass reduces cutting efficiency, adds weight, and can interfere with the blade disc rotation. A clean undercarriage also allows you to inspect blade wear and check for damage from rocks or debris.