Plan on replacing suction cups every 12-18 months, brushes every 3-6 months depending on use, squeegee blades every 6-12 months, and water filters every 1-3 months on dirty sites. Total consumable spend runs roughly $900-$2,100 a year for a monthly-cleaned commercial roof.
Most premature robot failures are not electronic. They are rubber, bristle and filter. Get those four items on a calendar and the machine lasts years.
When do suction cups need replacing?
Suction cups fail gradually. The first sign is longer vacuum pull-down time, then occasional slides on wet glass. By the time a cup visibly cracks, grip has been compromised for weeks. Inspect cups monthly for glazing, hardening and embedded grit, and replace as a set, not one at a time.
On rooftops near construction or desert dust, cups can wear out in 8-10 months. Keep a spare set on site; a mid-job cup failure means a wasted shift.
How do you know when a brush is done?
Watch the water you squeeze out. A worn brush leaves visibly dirtier runoff and needs more passes to clear a panel. Measure it: if a panel that used to take one pass now takes two, the brush is finished. Soft microfibre rolls on coated low-E glass wear faster than stiff brushes on plain glass.
- Brushes: 3-6 months (shorter on coated glass).
- Suction cups: 8-18 months, replace as a full set.
- Squeegee blades: 6-12 months, or when streaks return.
- Filters: 1-3 months on dusty sites, up to 6 on clean ones.
Why does water filtration drive streak complaints?
Hard water leaves mineral spots as it dries. If your filter is clogged, dissolved solids pass through and dry onto the glass, and the roof looks dirtier than before cleaning. This is the number-one cause of “the robot made it worse” complaints. Change filters on schedule and check water hardness once a season.
Spot-free drying also depends on squeegee contact. A blade with a nick leaves a wet stripe that dries into a line.
What does a full service visit cover?
| Task | Frequency | DIY or service |
|---|---|---|
| Visual cup and blade check | Weekly | DIY |
| Filter swap | 1-3 months | DIY |
| Brush replacement | 3-6 months | DIY |
| Vacuum pump and seal service | Annually | Supplier |
| Tether and anchor inspection | Annually | Certified tech |
Who is bad at this?
Facilities teams with no single owner for the robot. When maintenance is everybody’s job, filters run clogged and cups crack unnoticed. Assign one person and a simple log. The buildings that get five years out of a unit are the ones that log cup hours and filter changes.
Spare parts and service plans for the K3, Y3 and S1 are on the contact page.
What does a realistic annual spares budget look like?
| Item | Interval | Annual cost |
|---|---|---|
| Suction cups (set) | 8-18 months | $300-$600 |
| Brushes | 3-6 months | $250-$600 |
| Squeegee blades | 6-12 months | $120-$300 |
| Filters | 1-3 months | $200-$500 |
| Detergent | Ongoing | $150-$400 |
Why do seals and pumps fail early?
The vacuum pump is the expensive heart of a suction robot, and it fails from dust, not age. Grit that bypasses the filter scratches the pump internals and degrades suction over time. That is why a pre-filter on dusty sites costs a fraction of a pump rebuild, which runs $800-$1,500 plus downtime.
Rubber door seals and tether sheathing are the other quiet wear items. A cracked seal lets water into electronics; a frayed sheath exposes the conductor. Both are cheap to replace and expensive to ignore.
How do you store the robot between jobs?
- Store cups relaxed, not compressed against a surface.
- Remove and dry brushes to stop mould.
- Keep the battery at partial charge, not full.
- Drain the tank and water lines to prevent freezing.
- Cover the unit in a dry, dust-free area.
What is the single best maintenance habit?
A five-minute end-of-shift inspection with a written log. Wipe the cups, check the brushes, glance at the tether anchor, and note the water quality. Teams that do this catch failures before they become breakdowns. Teams that skip it replace whole pumps.
How do you tell a cup is failing before it cracks?
Time the vacuum pull-down. When new, a cup seals in a second or two; as it ages, that stretches to three or four. Track that time monthly and you will replace cups before a mid-shift slide. This is a cheap measurement that prevents the most disruptive failure mode on a suction robot.
Also look for a permanent ring imprint on the cup lip. Once the rubber has taken a set, sealing degrades no matter how clean it looks.
What does a professional service visit include?
- Vacuum pump inspection and seal replacement.
- Motor brush and bearing check.
- Control board and sensor diagnostics.
- Tether and anchor load re-test.
- Full consumable audit and reset of the maintenance clock.
Should you do maintenance in-house?
Consumables yes, pump and electronics no. Changing cups, brushes and filters in-house is straightforward and cheap. Opening the vacuum pump or control board without training voids warranties and often makes things worse. Draw the line at the mechanical, and let the supplier handle the electrical.
Key Takeaways
- Rubber, bristle and filter cause most premature failures.
- Replace suction cups as a set every 8-18 months.
- Clogged filters cause mineral spots and “made it worse” complaints.
- Soft rolls on coated glass wear faster than stiff brushes.
- Assign one maintenance owner and keep a simple log.