My heat pump is whistling: what is the problem? How to cure it ?

 

My heat pump is whistling: what is the problem? How to cure it ?

Have you noticed that your heat pump is making noise or emitting a sort of hissing noise? Is this normal? When should you worry? How to reduce this hissing sound? The outdoor unit of a heat pump is never totally silent, but quite often the noise increases and becomes abnormal. We explain to you what problems can cause a hissing noise on a heat pump and how to fix it.

Noisy heat pump: is this normal?

One of the negatives in installing a heat pump is noise. Indeed, the heat pump system is not 100% silent and some models or some installations make more or less noise. It is almost always the outdoor unit that is responsible for the noise, especially because of the vibrations created by the fan. When installing it, the noise factor must always be taken into account and you must be aware of this detail. It is important to choose a place that does not disturb neighbors or yourself when you are in your garden or on your terrace, for example. New heat pumps are becoming quieter, manufacturers are trying to reduce noise as much as possible.
Certain noises or whistles should alert you, as they indicate a malfunction of the heat pump. A high-pitched hissing noise from the outdoor unit or hissing noise from the indoor unit is not common noises and you could end up without a heating system in the long run.

What causes a whistling heat pump?

Have you spotted a hissing sound or an abnormal noise on your heat pump? Here are the main causes of heat pump whistling :

• Defaulting or blocked holder;
• Security group not working properly;
• Valves of the device that are not fully open (the intermediate level can create hissing sounds);
• Circulator pipes lacking pressure;
• Expansion tank that lacks pressure;
• Possible leak in the ducts or leakage of the refrigerant liquid;
• Poor fixing of the system (indoor unit, outdoor unit, or piping);
• Powerboard that has a parasitic frequency.

There are causes that are not very important and can be easily repaired and more serious problems that require a  heating repair solution and the intervention of a professional.

Whistling heat pump: what are the solutions?

What to do when your heat pump whistles? Depending on the cause of the hissing, several solutions are possible:

• Expansion valve: it is necessary to replace it or put it back in place;
• Security group: to be changed;
• Lack of pressure: increase the pressure;
• Leaks: a professional must determine the presence of leaks and repair them;
• Fixing the heat pump: fix the system again or check the fixing at the level of the screws and nuts;
• Powerboard: a professional should check its operation and repair it if there is a problem.

If the vibration noise bothers you, but there is no problem with your heat pump, you can use soundproofing devices (screens, anti-vibration devices, etc.) to attenuate the noise.

Can you repair a whistling heat pump yourself?

It is not recommended to repair a heat pump yourself. It is a sophisticated and complex system that requires the intervention of a professional. We advise you to call on a qualified professional RGE (Recognized Guarantor of the Environment) to ensure serious and quality work, by a specialist in energy performance. At your scale, it is possible to try to identify a noise or whistle and locate it. If you realize that there is a lack of pressure, it is possible to increase it yourself or lubricate the fan to reduce vibration noise, for example.

When to contact a professional for a whistling heat pump?

From the moment you notice a strange hissing noise at the level of your heat pump system or any other type of problem related to your installation, it is advisable to call a professional heating engineer. A qualified craftsman provides repairs as soon as possible. Most problems with a heat pump are not easy to solve and must be repaired by a heating engineer. If a part is faulty, it is essential to order it and change it quickly for the system to work properly. Depending on the type of problem, troubleshooting can take from a few minutes to several hours.

Maintain your heat pump regularly

The best solution to avoid most problems on a heat pump is to carry out regular maintenance, as for a boiler. A failing system is often the result of negligence or oversight in maintenance. Maintaining a heat pump is essential to keep it in good working order, to increase its longevity, and to make it more efficient! But how do you maintain your heat pump?

• Dust the internal filters regularly;
• Clean the outdoor unit (remove leaves or the like);
• Raise the water pressure (for an Air/Water heat pump);
• Cover outdoor elements potentially sensitive to bad weather (with a tarpaulin, for example).

The maintenance of your heat pump system by a professional must be carried out every 2 years (for powers from 4 to 70 kW) and every 5 years above 70 kW.

Several causes can cause a whistle or an unpleasant noise on your heat pump (outdoor unit and/or indoor unit). In most cases, it is necessary to call in a professional heating engineer to fix the problem.