harvi connection guide
Fix Grid CT Lost
Grid CT Lost means your system has stopped receiving the grid readings it needs. If your grid CT connects through harvi, follow these checks to restore the radio connection to your zappi, eddi or libbi. Charging or diverting pauses until the required readings return.
Step 1 of 6
Check whether harvi is being heard
A brief interruption often clears on its own. If Grid CT Lost keeps appearing, check the linked devices list on your primary controller, labelled Master or Load Controller depending on firmware.
On your primary controller
Menu > Other / Device Settings > Installer Settings > Passcode (default: 0000) > Linked Devices > Devices
Select Other Settings or Device Settings, as shown on your screen. Enter your installer passcode. The default is 0000, unless it has been changed.
harvi has a ? beside it
The controller has lost communication with harvi. The entry remains in the list, but harvi is not currently being heard. Check the signal path and channel before removing it.
harvi is missing from the list
Confirm you are checking the primary controller. If harvi is still missing, complete the connection and power checks, then use the final re-pairing step.
If harvi is listed without a question mark but the error remains, ask your installer to check its grid CT configuration and readings. Being listed alone does not confirm the CT setup is correct.
Help centre: pairing devices and checking the linked devices list
Step 2 of 6
What is between harvi and the controller?
Think about the route between harvi and the primary controller. If zappi is a secondary product, the link to check is between harvi and the primary controller, which might be eddi or libbi.
Even a short distance becomes difficult when the signal must pass through metal or several solid walls. Check what has changed since the connection last worked reliably.
Is a car now parked in the signal path?
A car or van parked between harvi and zappi, or whichever product is the primary controller, is a large metal obstruction. Its bodywork reflects and weakens the radio signal. This is signal obstruction rather than the car necessarily transmitting interference.
As a comparison test, park elsewhere if practical and check whether the question mark and Grid CT Lost notification clear. Note whether the problem returns with the vehicle in its usual position.
If parking position affects the connection, ask your installer for a location that works with the vehicle parked normally. A reliable installation needs to work during everyday use.
Foil-backed insulation and metal in walls
The metal layer in foil-backed insulation reflects and blocks part of the RF signal. Insulated plasterboard, foil-faced panels and metal cladding make the signal harder to receive on the other side.
Consider recent insulation work, garage conversions or new wall coverings. A wall that looks like plasterboard might contain a metal layer. Reducing distance alone does not always overcome this obstruction.
Thick walls, concrete and several rooms
Stone, brick and concrete weaken the signal. Reinforced concrete also contains metal. Several walls or floors between products add to the loss, even when the straight-line distance is short.
Record the number and type of barriers for your installer. A clearer route often helps more than a small reduction in distance.
Garage doors, gates and metal enclosures
A closed metal garage door, roller shutter or gate changes the signal path. Metal meter cabinets, consumer-unit enclosures and metal sheds also obstruct radio communication.
Compare the connection with a normal garage door open and closed where practical. Leave electrical enclosures closed. If the result changes, ask your installer to review the mounting position.
Storage, appliances and reflective surfaces
Look for new shelving, metal cupboards, tool chests or large appliances near harvi or in the route to the controller. Fridges, washing machines, metal sinks and baths, and mirrors are factors identified in the zappi installation guidance.
Move ordinary stored items away where practical. Do not move fixed electrical equipment or pull on the CT cable.
Nearby radio equipment and electrical products
Other equipment using a similar radio frequency sometimes interferes with reception. Note whether the fault started after new equipment was installed or happens when particular equipment is used.
Changing the myenergi radio channel is the next comparison test. A strong Wi-Fi signal or a nearby Wi-Fi booster does not prove that the harvi RF link is strong.
Mounting height, orientation and recent building work
Mount harvi vertically and as high as practical. A low position behind a car, metal cupboard or stored materials leaves more in the signal path.
Extensions, scaffolding, new doors and changes to storage also deserve a check. Ask your installer to relocate harvi if improving the position requires mounting or cable changes.
The vehicle and storage checks apply the general guidance about metal obstructions to everyday installation conditions.
Help centre: harvi connectivity · zappi installation manual: factors affecting RF, page 8
Step 3 of 6
Check the channel on every linked product
Every linked myenergi product must use the same channel. If you have more than a primary controller and harvi, changing those two alone is not enough.
- Note the current channel on each product. On screen-based products, check Information > Page 3. Briefly press the harvi pair button and count its blue flashes. One flash means channel 1, four mean channel 4. It then enters pairing mode.
- Choose a common channel supported by all products. myenergi recommends channel 1 or 4 for most installations. Older products with serial numbers starting with 1 need channel 1 or 4.
- Use Menu > Other / Device Settings > Installer Settings > Passcode (default: 0000) > Linked Devices > Channel on screen-based products. Follow the linked guide for the harvi and hub buttons.
- Set every linked product to the chosen channel. Recheck the list when finished.
Communication pauses while products are on different channels. Once all settings match, check whether harvi is heard again. A channel change alone does not normally require re-pairing.
Step 4 of 6
Check the harvi light and grid readings
harvi harvests energy through its CT connections. It has no battery to replace and does not need a separate power supply. Check its status light during normal use when current is flowing through the monitored cable.
Flashing green
This is harvi's normal operating indication. It does not prove the controller is receiving its messages. Check the linked devices list as well.
No green flashes
Record this for your installer or Customer Care. The installation guide allows up to two minutes for green flashes to start when current is flowing. A dark light alone does not establish that harvi is faulty.
Installer checks if readings are still missing
Check the CT connection, cable condition and configuration for the actual installation. Confirm the intended harvi input measures Grid, and that the grid measurement is not also assigned to another product. A three-phase installation needs the appropriate three-phase CT configuration.
The ~ symbol identifies the grid CT source. There should be one grid measurement source in the system, using one CT for single phase or the appropriate set for three phase.
Leave CT wiring and electrical enclosures to your installer. Do not change a Grid CT to None as a way of clearing the notification.
Help centre: harvi installation and configuration · Help centre: grid CT setup and errors
Step 5 of 6
Improve a weak signal path
If the checks point to distance or obstructions, ask your installer to make a lasting improvement before re-pairing.
Relocate harvi
Choose a higher, vertical mounting position with fewer barriers to the primary controller. Check reception with the car parked and garage doors in their normal positions.
Extend the CT cable if required
Using twisted pairs, an installer has the option to extend the CT cable up to 100 m so harvi sits within reliable radio range. This extends the CT wiring, not the RF range.
Review the controller and RF antenna
Where suitable, an installer could use eddi or libbi with its external RF antenna as the controller, or review a compatible high-gain RF antenna. Keep the existing controller where practical. A role change affects the wider system and its pairing.
Consider a wired CT route
If no reliable RF route is available, ask your installer whether the grid CT could be wired directly to a suitable product. They must check the cable route and CT configuration for your installation.
Step 6 of 6
Re-pair harvi if the link is still lost
If harvi is still missing or marked ?, re-pair it with the primary controller. Complete the signal, channel and power checks first.
- On the primary controller, open Menu > Other / Device Settings > Installer Settings > Passcode (default: 0000) > Linked Devices > Devices. Select the existing harvi entry and choose Remove Device. Skip removal if no entry exists.
- Follow the help centre pairing guide. Pair harvi with the primary controller only, keeping the channel matched. Where a Communications Mode menu is present, check Radio Pairing is enabled.
- Verify the discovered serial number matches your harvi and accept it. Wait for pairing to finish and the ? to disappear.
- Ask your installer to confirm the saved CT assignments and phase mode, then check grid readings and normal operation. Monitor again with the usual vehicle and door positions.
Open the re-pairing instructions
Re-pairing restores the association. It does not remove a metal obstruction or improve the radio path. If the fault returns, send Customer Care the checks and results below.
Connection restored
Your connection is working again
If Grid CT Lost returns, use the guide to check placement and the radio channel.
Understand the notification
Why it happens
harvi uses a separate radio link
harvi communicates with your controller over RF. It does not rely on your home network, so it continues communicating if your Wi-Fi changes or drops out.
Distance, obstructions and radio interference affect this link. A repeated Grid CT Lost notification usually points to a connection that needs improving.
Why did this start after updating to firmware version 5?
Version 5 firmware on the controller reports brief interruptions that earlier firmware did not flag. This does not necessarily mean your installation has developed a new fault.
Version 4 and earlier
Charging or diverting continued for up to an hour after the link dropped. An error appeared if the connection did not return, so short interruptions often went unnoticed.
Version 5 onwards
If the connection is lost for 30 seconds, Grid CT Lost appears and charging or diverting pauses until the link returns.
This faster response was introduced for wirelessly connected grid CT clamps to meet Engineering Recommendation G100 Issue 2, 2022 Amendment 2.
If the notification started after updating from version 4, follow the connection checks in this guide.
Contact us
Still seeing Grid CT Lost?
Send Customer Care these details so we understand what you have already checked.
- The serial number and firmware version of your zappi, eddi or libbi.
- The primary controller, harvi serial number and every other linked myenergi product.
- Whether harvi is listed, missing or marked with a question mark, and its status light.
- The radio channel on each linked product.
- The approximate distance between harvi and the controller.
- Any walls, foil-backed insulation, metal enclosures or vehicles in the signal path.
- Whether the fault changes with parking position or the garage door open or closed.
- How often the notification appears and whether it clears on its own.
- The checks and changes completed, including the re-pairing result and any installer CT checks.
- Whether this started after a firmware update.