Robot Mower RTK Signal Lost: Causes, Antenna Placement, and Fixes

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Nine times out of ten, the antenna is in the wrong place

“RTK signal lost,” “weak signal,” “positioning failed,” Float instead of Fix: these all mean the same thing. Either the mower or the reference antenna cannot see enough clear sky, or the two have stopped talking to each other. Check power and cable first. Then move the antenna higher and into open sky, then exclude the shaded corner from the map. If the whole yard is under canopy, no antenna position will save you, and a LiDAR or vision mower is the honest answer. Below is why it happens, the placement rules straight from Navimow’s and Mammotion’s manuals, and what to try in order.

What RTK is, in plain terms

Plain GPS puts your phone within a few meters. That is fine for driving, useless for keeping a mower off your flower bed. RTK (real-time kinematic) fixes it with a second witness. A reference antenna sits in a fixed spot in your yard and listens to the same satellites the mower hears. Because the antenna knows exactly where it is, it can work out how much the satellite signals are being bent on their way down (Navimow’s manual mentions the ionosphere) and send that correction to the mower by radio. Navimow’s H-series manual puts the result at “the centimeter level.” Mammotion’s LUBA 2 manual says “approximately 5 cm (2 in).”

That is also the catch. RTK needs three things at once: the mower sees enough satellites, the antenna sees enough satellites (ideally the same ones), and the correction link between them is working. Lose any one and accuracy drops from centimeters to meters, and the mower stops rather than guess.

If you are still shopping, our RTK vs LiDAR vs vision guide covers which navigation suits which yard. This page is for people who already own an RTK mower and want it to stop stalling.

Fix, Float, Single: what the status means

Mammotion’s app shows the positioning state by name, and its support article defines each one. Navimow’s app uses similar language (Fixed, Float, Standalone, per trunetto’s fix guide).

Status	Accuracy (Mammotion)	Mows?	What it tells you
Fix	Under 10 cm, down to 2 cm in open sky	Yes	Everything is working
Float	About 50 to 200 cm	No	Corrections are arriving but one side cannot see enough good satellites. Usually trees, walls or fences near the mower or the antenna
Single (Standalone)	Meter-level	No	No correction data at all. With the station’s satellite count at zero and connection “None” or “Weak,” the antenna is off, unplugged, or its radio link is down
None	No position	No	Mower sees no satellites. Indoors, under a metal roof, or a hardware fault
Source: Mammotion support, “About the NEW positioning information”. Mammotion adds that both robot and station can see more than 20 satellites and still read Float if signal quality is “weak” or “bad.”

The useful distinction is Float versus Single. Float is a sky problem. Single is a link or power problem. Mammotion’s status screen helps you tell them apart: it shows satellite counts for the robot, the reference station, and the “co-viewing” set both can see. If the station’s count is zero, start at the station. If both counts are healthy but quality reads weak, start looking up.

Why the signal drops

Tree canopy. The number one cause, and the number one owner complaint. MowScout’s roundup of Navimow owner reports calls satellite loss under trees or near buildings “the single most-reported Navimow complaint.” Navimow’s own Academy post says signals “usually drop if the mower is under a thick tree canopy, in a narrow space, or around a multi-story wall.” Leaves absorb and scatter the signal. A spot that worked in April can fail in June when the canopy fills in.
Buildings and walls. A wall blocks half the sky. Two walls block most of it. Navimow’s manual says a map “should not be built between two high walls.” Mammotion’s support article names “high trees / walls / metal walls” as the reason a docked robot can lose Fix.
Multipath (reflections). Signals bounce off metal roofs, glass, cars, pools, and long flat walls, and the antenna cannot tell the echo from the original. Navimow’s manual calls this out by name and recommends installing the antenna “far from the house.” Zippy Lawnz, a Pennsylvania installer, makes it one of its four rules: keep clear of big metal, glass and water.
Antenna too low. Height is the fix most people skip. A low antenna sees a fence and a hedge; a high one sees over them. Navimow’s manual says that if the antenna’s indicator will not turn green or blue on the ground, use the extension kit and mount it on a roof or wall.
Antenna moved. The map is built relative to the antenna’s position. Mammotion’s support site is blunt: move the station and “you’ll need to delete the current map and recreate it.” Navimow says the same. A knocked pole, a wobbly fence mount, or a well-meaning relative who “tidied up” the antenna will shift every boundary on the lawn.
Satellite geometry changes through the day. Satellites move. A marginal spot with half the sky blocked can have enough satellites overhead at 9 a.m. and too few at 3 p.m. Mammotion’s status screen shows the live co-viewing count for exactly this reason. If your mower fails at the same time every day in the same spot, that is the pattern to look for.
Cable and power. trunetto’s guide puts “cable damage from lawn mowers, trimmers, or animals” as the second most common cause after placement. Navimow’s codes 5001 and 5005 (“unable to connect GNSS antenna,” “GNSS antenna data error”) both say to check the antenna connection to the charging station. Mammotion’s Single status with zero station satellites means the same thing.
Firmware and Wi-Fi. Navimow’s Academy article lists outdated firmware and a weak Wi-Fi network as causes of “weak signal” symptoms, the latter because the app’s map and location lag. These are the exceptions, not the rule.

Antenna placement rules, from the manuals

Navimow and Mammotion publish nearly the same rules with different numbers. Zippy Lawnz’s summary is that “it’s the same physics.” Here they are side by side.

Rule	Navimow (H-series manual, Academy)	Mammotion (LUBA 2 manual, support)
Sky view	At least 110° of unobstructed sky; nothing overhead such as tree canopy or a sunshade	“Open area to receive satellite signals”; no eaves or trees that obstruct
Distance from walls and trees	Greater than 2 m (about 6.5 ft)	At least 3 m (10 ft) from any wall or tree; support article says no cover within 5 m if possible
Orientation	Upright, not at an angle	Vertical
Ground or roof	Flat, non-hardened ground next to the dock, or roof/wall with the Antenna Extension Kit (sold separately)	Flat open ground on the included pole, or “an unobstructed wall or roof” with the RTK Wall Mount Kit (sold separately)
Height	Manual gives no minimum; extension kit exists to get it “at a higher position”	Manual gives no minimum beyond the pole; wall kit is for “a high place of your house”
Distance to the mower	Code 4011 fix says keep the mower within 200 m of the charging station (the dock relays corrections)	Extension cable is 10 m (33 ft); radio link range not stated in the manual
Things to avoid nearby	Sprinkler heads, fountains, substations, generators, pump stations, air conditioners; long flat, glass or metal walls	Metal behind the robot; the corner of an L-shaped building for the dock
If you move it	Create a new map	Delete and recreate the map
Lightning	“Roof top antennas of any sort should have lightning protection”	Not addressed in the pages we read
Sources: Navimow H-series User Manual V2.1 sections 1.6, 1.7, 2.2 and 5; Navimow Academy; Mammotion LUBA 2 AWD User Manual pages 24 to 34; Mammotion support.

Two installer and owner-reported numbers fill the gaps the manuals leave. trunetto suggests mounting at least 1.5 m high and 3 m from large metal, and says it can take 5 to 15 minutes after power-on to reach Fixed. Zippy Lawnz reports about 600 ft of line-of-sight radio range between a Navimow antenna and mower in its own test, “meaningfully less through trees,” and tells the story of a 25-foot pole that lifted a reference station above a canopy two other installers had given up on. Those are field reports rather than specs, so treat them as upper bounds.

The dock and the antenna do not have to be together. Both brands ship the antenna attached to or beside the charging station, so most people leave it there. But the dock goes where the mower can reach it. The antenna goes where the sky is. Navimow’s extension kit and Mammotion’s 10 m cable plus wall kit exist for exactly this reason. Zippy Lawnz calls the “it belongs next to the dock” belief the biggest misconception in RTK installs.

The fixes, in order

Check the status screen, not the lawn. Mammotion: tap the status bar, read Positioning, the R/B/C satellite counts and signal quality. Navimow: look for Fixed, Float or Standalone in the app. Single or Standalone with a zero station count sends you to step 2. Float sends you to step 3.
Power and cable. Is the reference station LED solid green (Mammotion’s first instruction for “Poor Positioning Status”)? Is the antenna cable seated at the dock (Navimow 5001/5005)? Walk the cable for trimmer nicks. Unplug the station for a minute and plug it back in (Husqvarna gives the same one-minute advice for its EPOS reference station).
Restart mower and app, then update firmware. Navimow’s Academy puts this first among its fixes. Do it on a charged battery and strong Wi-Fi.
Stand where the mower stalled and look up. If you can see less than half the sky, the problem is local to that spot. Mammotion asks for a photo of exactly this view when you file a ticket.
Move the antenna higher and into the open. Follow the table above. Then remap; the old map is now offset. This single step is, by trunetto’s estimate, “about 75 percent of Navimow GPS problems.”
Make the mount rigid. Zippy Lawnz’s third rule. An antenna swaying an inch on a flimsy pole becomes an inch of mower error, and a season of slow drift.
Trim or exclude. Take out the one overhanging limb, or draw a no-go zone around the deep-shade corner. Navimow’s manual and Mammotion’s support both recommend excluding areas that repeatedly fail. A mower that skips the shade and does the other 90 percent is a win.
Switch correction source (Navimow, Mammotion). See brand notes below. If you are on network RTK and your cell signal is poor, try the local antenna. If you are on the local antenna and the yard blocks the radio link, try network RTK.
Add a second reference station or change navigation type. Husqvarna’s EPOS guidance says a dealer can add a second station on large or hilly lawns; Zippy Lawnz says a second Navimow antenna extends coverage. If the yard is mostly canopy, skip to the next section.

When to stop fighting it and buy a LiDAR or vision mower

Owners of every RTK brand report the same limit: a yard with heavy, continuous tree cover. Our buying guide treats shade as the first question for a reason. A rooftop antenna fixes the reference side of the equation, but the mower itself still has to see sky from under the trees, and no antenna placement changes that. Navimow’s own Academy post ends its “stuck under canopy” section by suggesting a mower with “multiple navigation technologies.” Zippy Lawnz, which sells and installs RTK mowers, says plainly that “under heavy canopy a LiDAR mower is the real answer.”

Signs you are past the point of fixes:

Float or weak-signal errors in most of the yard, not one corner, after you have tried a roof or pole mount.
Mapping never completes because no antenna spot gives a lock. MowScout cites multiple published reviews of setups that failed this way.
The mower works in spring and fails every summer when the leaves come in.

LiDAR and camera-based mowers build their own picture of the yard and do not need sky. Prices for current US models, as of October 2026 and in sale season: Navimow i215 LiDAR at $1,329 (list $1,599), Mammotion LUBA mini 2 AWD at $1,799, Mova Lidax Ultra 2000 at $1,199 (list $1,799), Ecovacs GOAT A3000 LiDAR Pro at $2,499.99, and Dreame A3 AWD Pro 2500 at $1,699.99 (list $3,099.99). Pure-vision models like the eufy E15 ($1,299.99) also skip RTK but have their own limits in low light and on some grass types. Pick by sky first, then by lawn size.

Before you buy anything new, check whether the model is one you can still get. The FCC’s 2026 Covered List action affects which new foreign-made mowers can be sold in the US. Our FCC tracker has the model-by-model status.

Brand-specific notes

Navimow

Two correction sources. Navimow’s newer models support Network RTK (corrections over cellular from a regional network of stations, no local antenna) as well as the local antenna. Navimow’s product pages say Network RTK access and the cellular data are included at no extra cost where coverage exists, with a postcode checker on the site. MowScout notes that the i105N, i110N and i210 AWD default to network RTK. The i210 ships with the local antenna in the box as a fallback for weak-4G areas. Zippy Lawnz points out that many owners never installed their antenna for this reason, and that the local antenna is the steadier option where cell coverage is patchy.
Network RTK still needs sky. It removes the “where do I put the antenna” problem, not the canopy problem. The mower’s own receiver still has to see satellites.
Dock link. On local RTK the charging station relays the corrections, so the mower must stay within about 200 m of it (code 4011). Navimow’s i2 AWD FAQ says that in network RTK mode, losing the dock connection for an extended period can throw code 4208.
Extension kit. Navimow sells an Antenna Extension Kit for roof or wall mounting. The manual’s lightning note applies.
Error codes 5001, 5005, 7003 and 7006 are the positioning family. Our error code table has the full list.

Mammotion

Three link modes. The LUBA 2 manual describes Antenna over Datalink (the station talks to the mower by radio), Antenna over Internet (the station sends corrections through your Wi-Fi), and iNavi Service, Mammotion’s network RTK, which needs no station at all. Mammotion’s iNavi page lists LUBA 3 AWD, LUBA 2 AWD X, LUBA mini AWD, YUKA and YUKA mini as supported, with the 4G data free for the product’s life, and says to check coverage first. US coverage is not spelled out on that page; check in the app.
RTK Wall Mount Kit. Listed at $139 on Mammotion’s US accessories page as of October 2026, for LUBA 3, LUBA 2 and YUKA. The LUBA 2 manual’s wall-mount steps use the included 10 m extension cable.
Don’t move it. Mammotion’s winter-storage instructions say that if the station is on a wall or roof you can leave the mount, reinstall the station in the same spot next season, and keep the map. Move it and you remap.
Code 1300 is “positioning status is poor.” The manual’s fix is to wait for repositioning; if it recurs, work the list above.

Husqvarna (EPOS)

Husqvarna’s wire-free Automowers use a reference station with the same physics. The message is “Reference station communication problem,” and Husqvarna’s US support article gives the same order of operations: check power, restart both devices, then move the station or add a stay-out zone, and on large or hilly lawns ask a dealer about a second station.

A note on what we did not find

Neither Navimow nor Mammotion publishes a minimum antenna height or a maximum radio distance in the manuals we read. The 1.5 m and 600 ft figures above come from an installer and a fix-guide site, not the brands. We also did not find a brand statement on how many satellites you need; MowScout cites Navimow documentation for “at least five co-visible satellites,” and trunetto suggests 15 or more for a reliable fix. Those numbers are not in conflict, they just answer different questions (minimum to work versus comfortable margin). If you have a manual page that pins any of these down, send it and we will update.