Q: How to use the buttons on the GRE HPM20 pool heat pump to set the temperature?

To use the buttons on your HPM20 heat pump: Basic Steps Press the ON/OFF button to start the device The screen will first display the desired temperature for 5 seconds , then the actual water inlet temperature Use the navigation keys to select a temperature between 10°C and 42°C Press the SET key to confirm your choice The screen then switches to permanently display the actual water inlet temperature Key Point Before Starting The filtration pump must be running before activating the heat pump. The device requires a circulation of at least 2 m³/h to operate correctly. Operating Conditions Your HPM20 only operates if the ambient temperature is above 12°C . Below this threshold, the unit automatically triggers its protection and stops. Indicator Lights LED 1: lights up when the heat pump is operating normally LED 2: lights up in case of a fault or anomaly

Q: Why does the charger light stay red?

The red light on the charger indicates that charging is in progress . This is the normal operation of the device. According to the GRE ELECTRIC VAC VCB10 manual: Red light = charging in progress Green light = charging completed, device ready for use The first charge is mandatory and lasts 3 hours . Please wait until the light turns green before using the vacuum cleaner. If after 3 hours the light remains red and does not turn green: Check that the charger is properly plugged into the wall outlet Check that the P1111 connector of the device is securely connected to the charger Make sure to charge in a well-ventilated area, indoors, away from sunlight and sources of ignition If the problem persists, the battery or charger may be defective - contact the retailer for a replacement

Q: Why doesn't the battery of the ELECTRIC VAC VCB10 recharge?

First, check the correct recharging procedure: Plug one end of the charger into the socket - the charger should show green Then connect the charger to the P1111 connector of the device - the LED turns red (charging in progress) Wait at least 3 hours - the charger turns green again when the battery is fully charged If the battery still does not recharge: Ensure that your hands and the charger are completely dry before plugging in Charge in a well-ventilated area, indoors, away from sunlight Make sure the charger is original - an incompatible charger will not charge the device properly Unplug the charger when not in use If after these checks the battery remains inactive and the charger LED does not turn red, the charger or battery is defective and must be replaced by the seller.

Q: How many reinforcements (braces) should I install on my GRE 7900872 pool?

You need to install the 6 reinforcements that you received. All 6 are part of the complete assembly of your GRE 7900872 pool. These 6 reinforcements (also called braces 90 in the manual) are used to stabilize and strengthen the structure of the 4 rows of wooden beams that make up the walls of your pool. They are distributed evenly around the pool to support the water pressure. Here’s how to use them: Install the 6 reinforcements before filling the pool Attach them to the outer side of the beams , at the top of the walls Distribute them evenly around the perimeter for uniform stability Tighten all provided bolts: insufficient stability may damage the structure The PDF manual (pages 44-48) contains the precise installation diagrams. If you find documentation indicating only 2, make sure it is indeed for your model (5.46 m × 3.95 m) - some smaller GRE pools actually require fewer reinforcements.

Question 1

How to use the buttons on the GRE HPM20 pool heat pump to set the temperature?

Accepted Answer

To use the buttons on your HPM20 heat pump:

Basic Steps

Press the ON/OFF button to start the device
The screen will first display the desired temperature for 5 seconds, then the actual water inlet temperature
Use the navigation keys to select a temperature between 10°C and 42°C
Press the SET key to confirm your choice
The screen then switches to permanently display the actual water inlet temperature

Key Point Before Starting

The filtration pump must be running before activating the heat pump. The device requires a circulation of at least 2 m³/h to operate correctly.

Operating Conditions

Your HPM20 only operates if the ambient temperature is above 12°C. Below this threshold, the unit automatically triggers its protection and stops.

Indicator Lights

LED 1: lights up when the heat pump is operating normally
LED 2: lights up in case of a fault or anomaly

Question 2

Why does my GRE PP075 pump stop running or shut off repeatedly?

Accepted Answer

If your GRE PP075 pump stops or shuts off regularly during operation, several causes may be responsible:

Cut-off due to thermal protection

The pump is equipped with a built-in thermal protection that automatically stops the motor when it overheats. Check that:

The motor has at least 1 meter of free space around the pump for proper ventilation
The pump is not exposed directly to sunlight or enclosed in a confined space
The motor's air vents are not blocked by dust or debris

If the pump stops, allow it to cool for a few hours before restarting. Insufficient ventilation is the most common cause of repeated cut-offs.

Water circulation issues

A stop may also result from disrupted water circulation:

Check that the pipe diameter is at least 50 mm (2") in PVC
Regularly clean the pre-filter basket to avoid blockages
Ensure that the suction and discharge pipes are not pinched or blocked
Check that the pump is properly filled with water before starting (priming)

Pre-checks

Before any use, confirm that:

The power supply voltage matches exactly 230V ~ 50 Hz indicated on the nameplate
A residual current device (RCD) of ≤ 30mA is installed on the circuit
The pump is placed on a stable and horizontal support

If after these checks the pump continues to stop, contact the manufacturer's technical support quoting the model number PP075 and the manual code.

Question 3

Are there videos or tutorials to learn how to use the GRE AR124 skimmer?

Accepted Answer

The GRE AR124 manual includes detailed diagrams (figures 5-9) explaining the installation and operation of the skimmer, but does not offer an integrated video in English.

Here’s how the skimmer works:

Water is drawn from the surface of the pool by the skimmer
The skimmer basket captures leaves and debris
The filtered water passes through the synthetic cartridge (model AR86) at a flow rate of 3.8 m³/h
The clean water returns to the pool

Installation tip: Position the skimmer facing the prevailing winds to direct surface debris towards the filter.

Regular maintenance: When the water flow decreases, clean the cartridge using a low-pressure water jet to remove impurities. Replace it after several cleanings if efficiency drops.

For a video tutorial in French, a YouTube resource titled “Installation skimmer et refoulement sur une piscine Gré” shows similar steps applicable to your model.

Question 4

Why does the charger light stay red?

Accepted Answer

The red light on the charger indicates that charging is in progress. This is the normal operation of the device.

According to the GRE ELECTRIC VAC VCB10 manual:

Red light = charging in progress
Green light = charging completed, device ready for use

The first charge is mandatory and lasts 3 hours. Please wait until the light turns green before using the vacuum cleaner.

If after 3 hours the light remains red and does not turn green:

Check that the charger is properly plugged into the wall outlet
Check that the P1111 connector of the device is securely connected to the charger
Make sure to charge in a well-ventilated area, indoors, away from sunlight and sources of ignition
If the problem persists, the battery or charger may be defective - contact the retailer for a replacement

Question 5

Why doesn't the battery of the ELECTRIC VAC VCB10 recharge?

Accepted Answer

First, check the correct recharging procedure:

Plug one end of the charger into the socket - the charger should show green
Then connect the charger to the P1111 connector of the device - the LED turns red (charging in progress)
Wait at least 3 hours - the charger turns green again when the battery is fully charged

If the battery still does not recharge:

Ensure that your hands and the charger are completely dry before plugging in
Charge in a well-ventilated area, indoors, away from sunlight
Make sure the charger is original - an incompatible charger will not charge the device properly
Unplug the charger when not in use

If after these checks the battery remains inactive and the charger LED does not turn red, the charger or battery is defective and must be replaced by the seller.

Question 6

What does error code P2 mean and how should I react after a power outage?

Accepted Answer

The error code P2 indicates a fault in the ambient temperature sensor of your GRE HPM20, HPM30, or HPM40 pump. This sensor is either open circuit or short-circuited - it is no longer communicating with the device.

After a power outage:

Your pump has a 3-minute timed restart protection, even for a very brief interruption.
Wait at least 3 minutes before the pump automatically restarts.
If the P2 code persists after this delay, check that the sensor cable has not been disconnected during the power restoration (it may just need to be reconnected).

Solution:

If the problem persists, the ambient temperature sensor needs to be replaced. This intervention requires the assistance of a qualified technician. Do not attempt to repair the sensor yourself.

Note: Your pump may continue to operate with this error code, but heating will be less effective as the pump will not be able to adjust its power to the outside temperature.

Question 7

Why does the pump stop automatically after 45 minutes of operation?

Accepted Answer

The pump is protected by a thermal automatic shut-off system that activates to protect the motor from overheating. This stop after 45 minutes is generally a sign that the motor has reached a critical temperature.

Possible causes:

Insufficient ventilation: Ensure that the pump and motor have adequate ventilation around them. Leave a clear space for air circulation.
Blockage or seized shaft: Check that the pump shaft turns freely and that no debris (leaves, sand, lime) is blocking the passage.
Clogged filter: A dirty pre-filter forces the motor to work harder and overheats more quickly.

What to do:

Turn off the power to the pump immediately.
Allow the motor to cool down before restarting.
Clean the pre-filter and check for blockages.
Ensure that the pump has sufficient ventilation.
Restart the pump.

If the automatic shut-off occurs regularly even after cleaning and checking, there may be a defect in the motor. In this case, contact a qualified technician.

Question 8

Where to fix the GRE L4PL ladder in the pool?

Accepted Answer

The GRE L4PL ladder must be fixed inside the pool, at the location you choose for entering and exiting.

Positioning

Position the ladder so that the anti-pinch barrier is facing inward towards the pool
After placement, move the ladder back and forth to eliminate trapped air

Fixing to the pool edge

The ladder is fixed with bolts and nuts to the two holes in the platform (dimensions: 1070 x 646 mm).

Specific steps:

Align the two holes of the platform with the edge of the pool
Mark the positions with a fine marker
Drill the edge of the pool with a 5/16 inch bit
Secure with the provided bolts, nuts, and washers

The provided bolts vary according to the height of the ladder: reference 5862050001 for models 121-137 cm, or 5862050000 for the 120 cm model.

Tip: A ladder mat (sold separately) is recommended to facilitate installation.

Question 9

What tools to use to insert the posts of the GRE L4PL ladder?

Accepted Answer

To insert the posts (rails) of the GRE L4PL ladder, no specialized tools are strictly necessary for this step. The posts are manually inserted into the slots provided on the bottom step.

Preparation and insertion of the posts:

First, place the bottom step on a flat surface, with the ribbed side facing up
Simultaneously insert the two rails (posts) into the slots - they must be oriented in the same direction for proper alignment

Tools required for complete assembly:

Once the posts are in place, you will need the following tools for assembling the rest of the ladder:

Screwdriver - for No. 10 × 1-1/4 screws (attaching the steps)
Wrench or socket - for M6 bolts and nuts (attaching the left and right braces)
Rubber mallet or hammer - to install the caps on the rails
Saw - only if you need to shorten the posts (pool less than 137 cm high)

Important: Do not overtighten the M6 bolts when securing the braces to avoid damaging the material.

Question 10

How many reinforcements (braces) should I install on my GRE 7900872 pool?

Accepted Answer

You need to install the 6 reinforcements that you received. All 6 are part of the complete assembly of your GRE 7900872 pool.

These 6 reinforcements (also called braces 90 in the manual) are used to stabilize and strengthen the structure of the 4 rows of wooden beams that make up the walls of your pool. They are distributed evenly around the pool to support the water pressure.

Here’s how to use them:

Install the 6 reinforcements before filling the pool
Attach them to the outer side of the beams, at the top of the walls
Distribute them evenly around the perimeter for uniform stability
Tighten all provided bolts: insufficient stability may damage the structure

The PDF manual (pages 44-48) contains the precise installation diagrams. If you find documentation indicating only 2, make sure it is indeed for your model (5.46 m × 3.95 m) - some smaller GRE pools actually require fewer reinforcements.

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