Why Is My Mini Split Not Heating My Home Or Not Blowing Hot Air?

Guide: Why Is My Mini-Split Not Heating or Blowing Hot Air?There are many possible reasons why your mini split isn’t blowing hot air or warming your home. Most of them boil down to buildup inside the air handlers that prevent airflow or heat transfer. Now, there’s an easy fix for that.

This article walks you through the four most common reasons a mini spit won’t work correctly. You can handle a few of these on your own. For others, you’ll need a professional.

But, the good news is that in many cases, that professional isn’t an HVAC contractor. Instead, you can schedule a mini split cleaning that usually solves the problem — and offers a few other benefits as well.

Of course, we need to warn you not to start taking apart your air handler or heat pump. These units have some tiny, delicate parts in there. It’s easier than you may think to make the problem much worse.

Related: Mini Split Improper Installation: What Could Go Wrong?

Instead, run through our quick DIY troubleshooting. Then, give HydroKleen208 a call if you’re in Valley County or Boise Metro here in Idaho. We’ll answer your questions over the phone and help you decide if cleaning is the right move. You can reach us at (208) 779-5596.

Four Common Reasons Your Mini Split Is Not Blowing Hot Air

The four common things to check for when your mini split is not heating your home or blowing any hot air are:

  1. Wrong Thermostat Settings
  2. Dirty Or Clogged Filter
  3. Frozen Coil
  4. Clogged Coil

You can fix the first two yourself, and we’ll go through all four in-depth.

Wrong Thermostat Settings

Sometimes, the problem is simply the thermostat setting on your air handler.

For instance, if you don’t switch from “Cool” to “Heat,” your heat pump waits for the house to get warmer than the setting. In the winter, you want the opposite: Heat coming on when it goes below that call.

Or, there’s “Fan Only,” which only circulates air without moving heat around. This is more common on forced-air systems, but it’s an option here as well. In the winter, it would only move around the air in the room — which is cold when there’s no heat.

Read More: My Mini Split Won’t Turn On: Four Common Causes (And How To Fix Them)

What To Do

Check the thermostat on each air handler. Make sure they’re set to “Heat” and not “Fan Only.” Then, set them to the temperature you want.

Dirty Or Clogged Filter

The filter in your mini split traps all sorts of dust and debris. When that stuff floats through the air and into the air handler, the filter prevents it from going further into the unit and then blowing back out.

But that filter gets clogged eventually. When that happens, it blocks airflow. Now, your air handler is trying to move heat into the room. But, there’s no circulation, so you don’t get any hot air.

Related: How To Spot And Fix A Condensate Drain Line Clog

What To Do

Open the panel on your air handler and check the filter. Does it look like this?
A Dirty Ductless Filter

If so, clean it right away. Then, see if that solves the problem. If it does, make sure to clean it once a month from now on — that’s the usual manufacturer recommendation.

Frozen Coil

A mini split heat pump can “ice up” or “ice over.” It’s when water on the coil freezes. Then, it can’t draw in heat and circulate it inside your home. The result is a system running in the winter but delivering cold air instead of warmth.

The two main culprits here are a dirty coil or a refrigerant leak. We’ll talk about the coil in our next section.

A refrigerant leak produces freezing-cold air in the heat pump and on the coil. It’s so cold that all the moisture on it or in the air freezes up. It ices over and prevents heat transfer.







What To Do

Listen for hissing sounds or chemical smells near the heat pump. Those are signs of a refrigerant leak. IF you notice them, call your HVAC contractor right away.

If not, disconnect the power to your heat pump. Once the ice melts, power it back on. If it happens again, call a professional.
Meanwhile, visually inspect the coil if you can see it. Take off the filter in your air handler as well. If they are visibly dirty, you need a cleaning. That may solve the problem.

Clogged Coil

A clogged coil causes heating problems even if you don’t notice ice on the system. In fact, the ice problem is rare. A far more common symptom is air handlers not working as well as they used to is a far more common symptom.

Once again, the problem is a clogged coil: All sorts of gunk, from dust to even mold, builds up in between the tiny fins and prevents proper heat transfer and circulation.

It happens on the heat pump outside and inside your air handlers. And, it results in hot and cold spots in the house or getting cold air when you want heat.

What To Do

Start with a deep cleaning. It’s a more detailed, involved process than what you’d get with routine maintenance from your regular HVAC provider. And that’s no slight on them. It’s just that this is a specialized process.

What you want is a service that gets behind and inside every component of your air handler and mini split to flush out contaminants and eradicate any microbial organic pollutants.

Related: How Often Should A Mini Split Be Cleaned?

What Do You Get With A Mini Split Cleaning?

HydroKleen208 uses equipment and cleaning agents designed to quickly and completely flush and sanitize your entire mini split system. You’d be amazed (and probably grossed-out) by what lurks inside your air handlers and heat pump.

Here’s an example from a recent job. As always, we pause halfway through to show the homeowner the difference we’ve made. So far, we’ve cleaned the left side. Check out the horror show on the right:

And, we’re sorry to say, this isn’t an unusual case. If you’ve never had your system cleaned out before, your units probably look like this as well.

Fortunately, we can make a huge difference with one quick visit.

Related: What To Expect With A HydroKleen Visit

Mini Split Cleaning In Donnelly, ID

HydroKleen208 specializes in mini split deep cleaning for homes and businesses in Donnelly, ID, Valley County, and Boise Metro. We guarantee our tools and cleaning agents will get your mini split working like new. If they don’t, our visit is free. Click below or call us at (208) 779-5596.