Gas boiler Leopard - error codes, their meaning, malfunctions and how to fix them

Design and principle of operation of Leopard boilers

The Leopard double-circuit gas boiler from Proterm is a device capable of operating from both natural and liquefied gas, equipped with a bithermal heat exchanger. The throughput of liquid from the tap is 8 liters per minute, heated to 35 degrees.

Power consumption 135 W. Equipped with a built-in processor, it monitors the operation of the device by comparing sensor readings. If a problem is detected, the gas supply is stopped and a failure code is displayed.

This device is easy to operate, the efficiency during the heating season is 90%. Depending on the modification, it may be with natural or forced removal of combustion products.

Types of Proterm gas boilers are the most interesting for the domestic market

There are many modifications on sale. The most common are gas two-chamber boilers with biometric heat exchangers: Leopard and Lynx. The equipment is made at a high technological level and complies with EU standards. However, no matter how good the technology is, it has the ability to fail at the most inopportune moment. Read below about malfunctions of heating devices and troubleshooting methods.

Do you know how to properly arrange the chimney of a domestic gas boiler? Find out: are there gas boilers without a chimney?

Basic error codes

Next, we will consider the most common errors of the Leopold gas boiler, and we will figure out what needs to be done to eliminate them.

a6

Error a6. Occurs due to low temperature in the room where the boiler is installed. The temperature in the room where the device is installed should not fall below 0 degrees; if this happens for some reason, install an electric radiator there.

f0

Error f0. Occurs when the pressure of the circulating fluid drops below 0.7 bar.

You need to do the following:

Increase the pressure in the heating system to the required value (1.5 bar). This can be done using a make-up tap.

Automatic heating system make-up valve

Then check all pipes for leaks. To do this, take a small piece of fabric and check all the connecting elements.
Check if the fluid pressure sensor is working properly.
Check to see if the expansion tank is working properly.
If the fall continues and you are unable to find the cause, contact a qualified professional for help.

f1

Error f1 (f1). Flame extinction. Occurs due to automatic blocking of the gas supply to the burner, since when the gas is open, a signal about the presence of a flame from the ionization electrode is not sent to the processor.

Necessary:

Reboot the device using the restart button.
Check the gas pressure, if you are using liquefied gas, it may have run out in the storage tank.
The electrical connection may be broken; turn the plug over in the socket.

Fan for boilers Leopard
The fan may be broken and due to overheating, the lock will be triggered.

f5

Error f5. Damage to the outside temperature sensor. And if it is absent, it signals low voltage.

Try the following:

Use a multimeter to check the electrical circuit of the sensor and the boiler for a break; if found, repair it. If the problem still persists after this, contact a qualified technician for help.
To equalize the voltage, connect the device through a voltage stabilizer.
Perhaps the problem lies in the sensor itself, or rather, in its malfunction; replace it with a new one.
Also, the problem may lie in a faulty board; have it tested and, if necessary, replace it with a new one.

Leopard boiler control board

f6

Error f6. Indicates that the traction sensor is open.

Check the following:

The traction sensor is faulty.
Check the sensor circuit with the board for an open or short circuit.
Check to see if the gas valve is working properly.
Check for a short circuit to the frame.
Test the fuse for serviceability.
The sensor that monitors heat exchanger overheating may be faulty.

Leopard boiler heat exchanger

f7

Error f7. Indicates a fault in the connection between the display and the board.

Check the following:

Try restarting the boiler.
Check the circuit board - display for an open or short circuit.
The phase is mixed up with zero, swap the plug.
The pressure in the coolant system has dropped below the permissible minimum. Top up the system to the 1-2 bar mark.

f8

Error f8. The gas valve has failed.

Check the following:

Integrity of the gas valve power connector.

Gas valve
Check the resistance in the gas valve coil.

On a note!

Protherm Leopard boilers are available in several modifications. The difference is in power, type of combustion chamber and method of smoke removal (BTV - forced, BOV - natural draft). In all other respects, the design is identical, and therefore errors for all versions of heating equipment of this brand are interpreted in the same way.

Protherm Leopard control panel discontinued
Protherm Leopard control panel

Whatever code appears on the Proterm Leopard display, you need to start the investigation by turning off and restarting the boiler. This is done with the main switch (on the lower end of the device, at the place where the pipes are connected: indicated by REZET). Access to it is free; you do not have to remove the casing.

Other faults

The boiler does not turn on due to:

no power supply, check the serviceability of the network connection, the network voltage, if it is less than 220V, install a transformer;
low pressure in the gas line, contact the gas utility;
the gas supply is shut off, open the tap;
there is no draft, make sure that the chimney is not clogged and the fan is working properly;
the electrode is not installed correctly relative to the jets, adjust the value between the electrode and the jets;
The gas valve is faulty, replace it with a new one.

The boiler is usually humming due to a large amount of deposits in the heat exchanger, flush the heat exchanger, air may get into the system, remove air, the fan or pump may be faulty, check their operation.

Proterm boiler diagram

Insufficient water pressure in the hot tap, check and wash the filters, if they are deformed or torn, replace them.

The flame is orange and burns unevenly - this happens if the burner and jets are dirty, clean them of soot with a brush and rag, blow the jets with a hairdryer.

F6.

Problem with traction. If the boiler is a BTV series (turbocharged), then the cause of the error should be sought in the area where the fan is located. The electronic board does not receive a signal from the corresponding sensor.

Check what

Condition of electrical circuits.
Fan performance. It may not be receiving voltage. Breakdown is a rare occurrence. When the blades rotate freely, mechanical defects are excluded; only the electrical part. It is not difficult to ring the motor winding.

Recommendation:

If the cause of the error is not identified, two options are possible - a malfunction of the electronic module or the fan (turn-to-turn short circuit). You can't figure it out on your own, call a professional.

Pro Tips

Imported equipment is sensitive to supply voltage parameters. Heating boilers are no exception, often producing false errors. To minimize the risk of Proterm Leopard stopping for this reason, it is recommended to connect it to the network via a UPS. The advantage of this solution is that the power supply will ensure uninterrupted operation of the unit even if the power supply is temporarily interrupted. During what period depends on the total capacity of the UPS batteries: from 4 hours or more.
When searching for the cause of an error on the boiler display, it is necessary to check the tightness of the plugs and the reliability of the electrical contacts. During operation, the structural parts of Proterm Leopard vibrate slightly and the quality of the connection may be impaired. According to statistics, about 45% of problems are caused by this factor.
If the result of self-diagnosis of the boiler and heating system is negative, the fault is in the Proterm Leopard electronic board. You'll have to contact a specialist.

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F0. Pressure drop in the heating circuit.

Its normal value for Proterm Leopard is 1.5 bar. It is easy to replenish the volume using a special valve at the bottom of the boiler (blue). But if the unit stops again after a short period of time and the same error appears on the display, you need to figure it out.

Probable Causes

Recommendation:

It’s not difficult to identify, you just need to carefully inspect the entire route. Wet spots and puddles on the floor will indicate the “culprit” for the F0 error.

Recommendation:

Remove the pump from the boiler and carry out maintenance. If the heating system with Proterm Leopard has a low-quality coolant, then in most cases it helps restore the functionality of the pump.

Solved Protherm Leopard board IRIS1.0 error F1

I still can’t get the exact letter and numbers of the model from the servicer. IRIS1.0 board. Atmospheric boiler. On the table, F1 appears with a strange symptom. It starts, reaches a spark, but the spark lasts less than a second and naturally goes to F1. However, during ignition nothing comes to the modulator. If during this short time of spark supply you manage to simulate a flame, then the board functions normally and voltage appears on the modulator. If during this operation you simulate an extinguished flame, then the board turns on the modulation fully (judging by the glow of the light bulbs) and the duration of the spark is normal 7-8 seconds.

I can’t understand why the initial spark has such a short duration, as if the board detects some kind of error when it is initially turned on, although it does not show any other errors. Someone on the forum wrote that his board (albeit SYMSI7.0) even checked the ignition transformer, although I have never encountered this. Just in case, I’ll say that the resistance of the primary winding of the high-voltage transformer ZIG 2/12 shows 920-980 kOhm (depending on the connection of the multimeter probes). In semiconductor testing mode it shows 1140, but only in one direction. Until now, there has never been a need to make such measurements, so I will ask you about the compliance of these readings with the norm.

In general, I ask for your magic kick in the right direction, otherwise my knowledge of the nuances of the operation of this board is still leading me to a dead end.

Theorist65

Recommendations for the user

If any error is displayed, not just code f1, you should not immediately look for the cause of the malfunction. The first thing to do is to restart the boiler (REZET switch). In 85% of cases, its performance is restored.

If the fault code appears again, you should check the set parameters. Incorrectly “clogged” power of Proterm Leopard often causes error f1.

During the initial start-up of the boiler, it may be caused by phase reversal. The wall-mounted Proterm is connected to the 220/1f network, and if “0” and “F” are mixed up, its automation will generate an emergency signal. You need to remove the plug from the socket, turn it 1800, insert it and repeat the start.