If you are seeing the CH 51 error code displayed on your LG air conditioner, then it means that your system is experiencing a capacity error.
There are many different benefits to installing a mini-split air conditioning system in your home, but the added convenience of cooling multiple spaces is one of the main advantages.
However, if your LG mini-split air conditioner (AC) is displaying a CH 51 error code, then you may have exceeded your system’s capacity.
The benefits of a ductless mini-split system
There are many reasons why ductless mini-split air conditioning systems are slowly becoming the fan-favourite choice among homeowners.
Not only are these systems fairly easy and cheap to install, but they also allow for more convenience and control over the heating and cooling of your entire home.
This is mainly because although you can install a single mini-split system with one indoor air handling unit and one outdoor condenser unit (the way you would with a larger, split HVAC system), you can also opt for what is called a multi-split system, which will give you the option to cool varying spaces in your home differently.
Some models also offer programmable features for scheduled temperature changes.
In multi-split systems, each indoor unit is controlled independently, allowing you to set different temperatures in different rooms, catering to individual comfort preferences.
LG air conditioner error code CH 51
Within a multi-split system, the singular outdoor condenser unit is connected to multiple indoor units in different rooms.
This means that you will have the ability to set the desired temperature, fan speed, and other controls of each space independently, without affecting the settings for the next space.
This additional control and customisation is part of what makes a ductless mini-split system so desirable. But, as with any system, the more components that are added to the system, the easier it gets for something within the system to go wrong.
If your LG mini-split air conditioner is displaying a CH 51 error code message, this is exactly what is happening. The CH 51 error code signifies a capacity error.
Since multi-split systems work by adding multiple indoor air inlets to a singular outdoor condenser system (which does not get bigger as more indoor units are added), it is quite easy for this system to become mismatched when the total area that needs to be cooled exceeds the capacity of the outdoor unit.
Most mini-split condenser systems can handle up to eight indoor air units (you can check the capacity of your specific model by searching for the label on the side of your indoor unit).
But every home will have its own specific needs. This means that your LG air conditioning system can be mismatched in terms of capacity, even if you have not technically exceeded the number of units or total area or rooms listed on the label.
Why the size of your air conditioner matters
The CH 51 error code may seem like nothing more than an unnecessary interruption when it first appears. But having an air conditioning system that is below or over capacity can cause some serious issues.
An undersized unit will burn out quickly trying to cool more air than it is capable of cooling adequately,. An oversized unit will short-cycle and have unnecessary wear and tear.
In both of these instances, you will end up sacrificing at least some of the comfort, energy efficiency and reliability of a properly-sized system.
What to do to fix the CH 51 error code
If your mini-split system is mismatched, there is really no permanent solution other than replacing the system with one which is properly sized.
However, in the meantime, you can try to lessen the load on the system as a whole by ensuring that you do the following:
- Try not to switch on all of the indoor units simultaneously
- Ensure that your home is properly insulated
- Turn off any appliances that could be causing your indoor temperature to rise
Reasons why you may need more air conditioning capacity
Sizing an air conditioning system is always tricky (which is why it is safest to rely on expert calculations).
But this process becomes even more difficult when a multi-split unit is involved and where the total spans multiple rooms.
Square footage is certainly one of the main considerations when it comes to determining the ideal size of an air conditioning system. But there are other things that can affect the total cooling capacity needed for your space.
If any of the following things are true of any of the spaces in your multi-split system, then you may require more cooling capacity than usual:
- If your home has high ceilings
- If you live in an area with a warmer climate
- If you have a high number of windows of lots of natural sunlight
- If your home is older