Is your Mitsubishi Electric air conditioner not blowing cold air even though everything seems to be running properly? An AC that isn’t cooling can be incredibly frustrating, especially during hot summer weather. But don’t worry – in most cases, it’s an issue that can be quickly identified and fixed so you can get back to enjoying cool, comfortable air.
In this blog post, we’ll walk through a systematic troubleshooting guide to help you diagnose exactly why your Mitsubishi Electric AC unit isn’t working. We’ll cover the most common problems that could be preventing your air conditioner from cooling properly and offer actionable solutions. Read on to learn how to get your AC back up and running!
Check Power and Electrical Connections
The first step in troubleshooting why your Mitsubishi Electric AC isn’t cooling properly is to check whether it has power and proper electrical connections. Here’s what you should look for:
- Check the electrical outlet – Make sure the outlet your AC unit is plugged into is actually supplying power. Try plugging in another appliance that you know works to test it. If the outlet is dead, you’ll need to flip the correct circuit breaker in your electrical panel back on.
- Check the plug – Ensure that the AC unit’s plug is securely inserted into the outlet. Also inspect the plug for any damage that could prevent proper power flow.
- Inspect the power cable – Check along the entire length of the cable for damage. Fraying, cuts, or crimping could be interrupting power delivery. Unplug before handling to stay safe.
- Test voltage – Use a multimeter if available to check voltage. You should measure around 220-240V. If voltage is low or nonexistent, there’s an electrical issue stopping your AC from turning on.
- Check electrical panel connections – If your AC is hardwired rather than plugged in, make sure all circuit breaker and wire connections involving the unit are intact and undamaged both outside at the condensing unit and inside at the air handler unit or ducting.
If you verify that your Mitsubishi Electric air conditioner has power but isn’t running at all when turned on, the issue is likely an electrical problem that will require a professional repair by an HVAC technician.
Ensure Your Thermostat is Working Correctly
If your AC unit turns on when you adjust the thermostat but fails to blow cold air, the issue may be with your thermostat settings. Here are some key things to check:
- Adjust temperature setting lower – Make sure your thermostat is actually set low enough to trigger cooling. Turn it down 5-10 degrees lower than the current room temp as a test.
- Inspect batteries – Thermostats often use AA or AAA batteries for power. Replace them if they show low charge levels.
- Check thermostat connections – Make sure wiring connecting the thermostat to your AC system is securely plugged in at both ends and undamaged.
- Power reset – Flip your thermostat off and back on to reboot, or remove batteries and reinsert if possible.
If adjusting your thermostat settings and connections fails to make your Mitsubishi Electric AC start cooling, there may be a problem with the thermostat itself requiring replacement. Testing with a known good replacement thermostat will confirm whether that’s the issue.
Check Refrigerant Levels
If your AC unit turns on but isn’t blowing as cold as it should, low refrigerant is often the issue. Refrigerant is the gas in the closed-loop system that gets cooled and condensed to produce cold air. Here’s how to investigate:
- Visually inspect refrigerant lines – Look for obvious signs of leaks like oily residue. Damage or corrosion can lead to slow refrigerant loss over time.
- Have refrigerant pressure tested – The only surefire way to check refrigerant level is having an HVAC technician connect gauges to check high and low pressure. They can then advise whether the level needs to be topped up.
- Conduct thorough leak testing – If your refrigerant pressure is confirmed to be low, comprehensive leak testing will be required to identify why it’s not holding charge. This may involve specialized tools.
- Repair leaks and recharge – Any refrigerant leaks will need to be repaired. Afterwards the system will need to be pulled into a deep vacuum and recharged with fresh refrigerant by weight to factory specifications.
Operating your air conditioner low on refrigerant can severely damage parts of the system like the compressor. Seek repair promptly to avoid an even costlier AC failure!
Check Condensate Drain and Drain Line
A clogged AC drain or condensate drain line can cause water accumulation that will in turn trigger certain safety shutoff mechanisms to cut power as a means of protection. Checking for the following can help identify or fix the issue:
- Inspect for standing water – Check beneath the evaporator coils enclosure inside your home, and the condensing unit tray outside for signs of excessive water that’s unable to drain.
- Ensure drain line is clear – Detach the drain line where visible to inspect for obstructions like sludge, mildew, or debris stuck in the plastic tubing. Clear accordingly.
- Check drain pump operation – For ACs that use a drain pump to expel condensation outward, test that the pump turns on and moves water properly. Replace it if faulty.
- Unclog condensate pan – The emergency drain overflow holes that prevent water spillover can become covered in slime and dust. Carefully unclog them with an antimicrobial cleaner and small brush.
If no visible drain obstructions are found, there may be an unseen crack in the internal drain pan requiring professional replacement. Preventing water back-ups will allow AC operation to resume.
Troubleshooting Is Key…When To Call A Pro for Repairs
We’ve covered the most common DIY fixes for a Mitsubishi Electric air conditioner that’s failing to effectively blow cold air during hot weather. But what about when you STILL can’t get your AC to cool reliably after methodically working through self-troubleshooting?
There comes a point where technical experience, electrical know-how, mechanical skill, specialized tools and licensure are required for adequate diagnosis and safe repairs. As a homeowner without HVAC training, it’s vital know your limits!
Here are key times to pick up the phone for professional assistance:
- Electrical issues involve unfamiliar circuitry or dangerous voltage levels. Don’t improvise!
- Refrigerant charging requires EPA 608 certification. Attempting improper handling risks fines over $37,000!
- Detection and repair of refrigerant leaks involves specialized equipment and uv dye injectors. DIY is not advisable.
- Condensate drainage issues linked to evaporator, pumps or coil pan damage often necessitate major service work only a certified HVAC technician possesses the skills to complete.
Mitsubishi Electric systems in particular use advanced inverter-driven compressors and proprietary control modules. Diagnosis can be complicated. Don’t hesitate to ask the experts for help!
By following sound troubleshooting methodology using our guide above as a starting point, you can accurately gather critical clues. This allows technicians to rapidly pinpoint WHY your air conditioner isn’t providing cold air. Combined with their technical expertise, your AC can be quickly restored to keeping your home reliably comfortable even on blistering hot summer days.
Don’t Suffer Through A Heat Wave…Contact The Pros Today For Rapid Resolution!
As we hope this air conditioner troubleshooting article has made clear, there are a range of issues that could be preventing your Mitsubishi Electric system from keeping your home nice and cool. But accurate problem identification is key so that cooling relief is just a phone call away!
Don’t drag your feet trying half-blind DIY repairs that fail to properly fix the issue.
One call to a top rated local HVAC company is all it takes to get your unreliable, underperforming AC back to doing what it does best: pumping out crisp, icy-cold air!
Many reputable technicians offer after hours and next day service. And repairs to get your AC running are often more affordable than you may think.
Don’t endure record summer temperatures if you don’t have to! Pick up the phone and breathe easier knowing you’ll soon be basking in frosty air conditioning again.
Your home comfort is our top priority. Just say the word and we’ll provide fast, expert Mitsubishi Electric air conditioner repair services tailored to your specific needs. Stay cool San Diego…we’re here when you need us!