HVAC Repair Tips


Heat pumps like other refrigeration systems use refrigerant or Freon. It’s the gas that travels inside the coils and makes heating or cooling possible. However, if your heat pump is not performing optimally, there may be a problem. One of them is low refrigerant levels. You need HVAC repair services to send an expert who can inspect your unit. If you think your heat pump is low on refrigerant, look for these signs.

Do You Need To Refill Refrigerant Frequently?

Refrigerant is a critical part of the heating or cooling process in HVAC systems and heat pumps, but it’s not consumed or evaporated in the process. So, your HVAC unit should not run out of. Ideally, you should not have to refill the refrigerant ever. If your heat pump has low refrigerant, it may be due to wear and tear, installation errors, or a leakage.

Signs Your Heat Pump Has Low Refrigerant Levels

Improper Heating In Winter

This is a vague sign as improper heating can have many reasons like clogged air filters, blocked vents, clogged drain lines, dirty condenser and evaporator coils, thermostat problems, and others. However, the heating of a heat pump is affected in the case of low refrigerant as well.

This is because refrigerant is required for the heating process in winter. When there is low refrigerant, the heat pump won’t warm up the house as usual. In this effort, it may overwork which can put strain on various components of the unit.

To determine if low refrigerant is the cause of improper heating, couple this sign with other signs listed here.

Hissing Noise

This is a huge sign of a refrigerant leak. It was explained earlier that refrigerant is not consumed by your heat pump so, mostly, low refrigerant levels are due to a leakage. Leaks can occur due to aging or lack of maintenance of the unit.

Usually, condenser or evaporator coils can suffer from tiny holes or cracks through which the refrigerant leaks and produces a hissing sound. So, if you hear a hissing sound near the condenser unit or the air handler unit, there is a leak in the condenser coils or evaporator coils. In case the cracks or holes are bigger, you might hear a gurgling sound.

Bubbles In Evaporator Coils

You need to check the air handler unit for this. If the leakage is in the evaporator coils, tiny bubbles may form from where the refrigerant is leaking. They may not be easy to spot, but if you do spot them, you can be sure that not only your heat pump is low on refrigerant, but it’s leaking from the evaporator coils.

After this detection, pass this matter to a heat pump expert who will fix the leak and, if needed, will refill the refrigerant. Bear in mind that only refilling the refrigerant without fixing the leaks won’t be beneficial because the refilled refrigerant will also leak out over time from the tiny holes formed somewhere.

Frozen Evaporator Coils

The leakage of refrigerant produces moisture. This moisture on evaporator coils freezes on the coils. This makes the heat pump’s job even more difficult. The heat pump can’t heat the house properly due to low refrigerant and now with frozen coils, the heating process will be affected even more. At some point, the heat pump will stop blowing hot air at all.

You can scrape off the ice from the unit or turn off the heat pump and it might melt the ice, but it won’t be helpful. If the evaporator coils were frozen due to dirty coils, you can have the air handler unit and the coils cleaned to fix the issue. But if the evaporator coils iced up because of a refrigerant leakage, fixing the leak is the only solution.

Frozen Condenser Unit

This sign is difficult to notice because, usually, condenser units are covered with snow in winter. To remove ice, heat pumps run a defrost cycle that removes this ice from the unit. So, if you see that your heat pimp’s condenser has been covered in ice for days, there may be an issue with its defrost functionality or ice may be forming due to a refrigerant leak.

Water Leakage

Water leaks from the evaporator coils or condenser coils when ice forms and then melts. In winter, water leakage will be hard to spot near the condenser unit because due to snow or rain, there may be water around the unit anyway. However, it’s easier to spot near the air handler unit which is installed inside a house.

When you spot leakage, check for any hissing or gurgling sounds. Moreover, check the evaporator coils for tiny bubbles.

High Humidity Levels

Heat pumps dehumidify the indoor space in winter to keep the place comfortable and warm. Due to low refrigerant levels and a refrigerant leak, this process will be affected. So, keep an eye on the humidity levels of your house and if there’s a drastic change, consult an expert who can check the unit and tell you what’s causing it.

Greasy Film On The Condenser Unit

Refrigerant of air conditioners and heat pumps is a colorless gas so detecting its leakage is difficult. If you can’t detect the leakage, you can’t tell if your heat pump has low refrigerant levels. A useful way of detecting refrigerant leakage is by having a look at the outdoor unit or condenser unit. In case of a leakage, there may be a greasy film on the condenser unit.

When refrigerant leaks, it commonly turns into liquid. This is the grease-like film you may see on your condenser unit. Call in a professional so you can have the issue fixed.

Longer Heating Cycles

In heating mode, the refrigerant becomes warmer near the evaporator coils and colder when it reaches the condenser coils. This process warms up your house. When there is low refrigerant, this process will be disturbed. So, your heat pump will take longer to reach the set temperature.

There are other reasons for longer heating cycles as well like dirty air filters, ignoring maintenance, leaky air ducts, and others. So, if your heat pump is taking longer to warm up the house and you also spotted some other signs mentioned above, then it’s due to low refrigerant.

Higher Electricity Bills

As your heat pump keeps running constantly, it will also use more electricity. If this keeps on going for more than a month, this extra usage will show up on your electricity bill as well.

Why Refill The Refrigerant?

The main reason is that your heat pump won’t warm up your house. However, there are many other reasons to fix the refrigerant leak and refill the refrigerant.

For instance, an HVAC unit works more when low on refrigerant. This increases the wear and tear of its components. So, running your heat pump with low refrigerant will also reduce its lifespan and increase the risk of the components needing repair or replacement. Along with that, you will also notice higher electricity bills.


Low refrigerant is mostly due to leakage. So, you should look for the signs mentioned in this guide to make sure your heat pump requires repair. If in doubt, hire a heat pump repair service McLean to spot the leaks and fix them.


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