Troubleshooting Beacon Morris Garage Heater Problems

Anyone who’s ever shopped for a garage heater knows the pedigree of Beacon Morris kick space garage heaters. Focused on bringing alternative solutions to home and work situations, the company makes highly dependable products with a high return on investment.

Their garage heaters, in particular, are designed for tough-to-fit areas that aren’t commonly warmed by central heating systems. 

Many consumers are also excited by Beacon Morris products because they stand up to property building codes for proper construction and ventilation, thus providing users with a safe, long-lasting heating solution. In a nutshell, Beacon Morris heaters are quiet, efficient, and easy to use. 

Common Problems and Solutions

Unfortunately, Beacon Morris garage heaters may also encounter issues. Although typically very reliable, they may occasionally refuse to ignite, begin to produce strange noises, or the motor may refuse to come on altogether. 

We’ve identified the seven most common Beacon Morris issues and solutions, so you’re prepared in case you encounter a problem in the middle of the night. 

NB: Beacon Morris garage heaters are programmed to flash an LED light for most common problems. Better still, the LED flashing is coded such that you can “tell” the potential issue merely by observing the flashing for a few seconds. 

So, this is where you should begin in case of a problem. Observe the flashing to “guess” the issue, then cross-reference with the troubleshooting guide to verify the actual problem and find potential solutions. 

1. Nothing Works; the Heater won’t Turn On

There are many reasons why the garage heater may refuse to work. The LED code will tell you the most likely issue. 

  • LED light not ON

If the LED light doesn’t come on at all, it means that power isn’t reaching the heater’s motherboard. Beacon Morris garage heaters are designed such that, as long as power reaches the internal motherboard, the LED light will turn on no matter the condition of the unit. So, if the light is completely off, the first thing to check is the power connection. 

Begin by checking whether the heater is powered ON in the first place. You might be thinking the heater is dead when the unit is unplugged at the socket. Make sure it’s properly connected and that the wires are in good condition. 

If it’s plugged ON and the wiring looks secure, check the fuse. Beacon Morris garage heaters have 3-amp fuses to protect the units from power surges. If the fuse blows, the power supply to the motherboard is cut. Thus, the unit will not work. So, make sure the fuse is working. A blown fuse usually turns black and has a funny smell. 

If the unit is plugged correctly and the fuse is in excellent condition, but the unit still won’t run, and the LED light is off, then you likely have a problem with your transformer or the power supply. First, check to ensure that 120-volts are present at the transformer (black and white) wires.

Alternatively, check the power supply. You should be able to see 24-volt wires (blue and yellow). If the transformer or power supply wires are missing, you need to replace them as appropriate. You may need an electrician for this task. 

  • LED produces steady slow flash 

If the heater isn’t running but the LED flashes, producing a steady, slow flash, the heater is likely in good condition, except that the thermostat is above room temperature. Nearly all heaters are designed to cut off the heating process when the thermostat setting is reached. Ensure that the thermostat wires are connected to the “R” terminal and “W” terminals on the control board. 

  • LED light produces a steady fast flash 

Finally, if the heater is “dead,” but the LED light produces a steady, fast flash, you may have a malfunctioned motor or motherboard. So, how can you know which of the two is affected?

It’s easy – check for the 120 volts at the CMB terminal on the motherboard. If 120-volt is present, you have a malfunctioned motor that needs repair or replacement. If 120-volts is absent, the motherboard itself is damaged and needs replacement.  

2. Exhaust Blower Constantly Runs with 120V Applied (with the Thermostat Disconnected)

This issue usually produces two LED flashes and may point to various issues within the heater. The faulty gas valve is the most common issue when the exhaust blower constantly runs with 120-volt applied with the thermostat disconnected. 

The gas valve delivers gas to the burner at a controlled pressure to facilitate reliable and safe heating. Since it’s an extremely sensitive component, it’s directly connected to the exhaust blower. Thus, a malfunctioned gas valve will directly impact the functioning of the exhaust blower system. Fixing the gas valve may require professional input. 

If it’s not the gas valve, then it’s likely the inlet gas pressure switch. This is especially true for propane heaters. The pressure switch is a safety feature that ensures all gases created in the combustion process exit your home and aren’t reintroduced into the system.

If this safety system malfunctions, the exhaust blower may run constantly. Make sure that the pressure is set per the rating plate. If the pressure is good, but the exhaust fan keeps running, change the pressure switch. 

3. The Heater is Short Cycling (Steady Fast Flash)

Short cycling occurs when the heater runs at shorter frequencies than in standard applications. For instance, a typical garage heater may cycle ON for ten minutes and OFF for 10 minutes repeatedly until you turn off the unit at the switch. However, during short-cycling, the same heater may only cycle ON for, say, five minutes, and then OFF for five minutes. 

The leading cause of short cycling in Beacon Morris garage heaters is fluctuating pressure. Begin by verifying opens during operation. If it doesn’t, fix it. If it does, check the pressure going to the switch. If it’s very low, below the switch setting, the system likely has a cut to the tubing or barbed connectors on the exhaust blower, which you must fix.

However, if the pressure doesn’t drop inside the tubing with the switch opened, you likely have a faulty pressure switch that needs replacement. 

4. Unit Locked Out After three Trials; Sparks but doesn’t Ignite (Two LED Flashes)

If the unit sparks but doesn’t ignite, the issue likely lies with the gas valve. Keep in mind that the Beacon Morris garage heater will lock you out after three trials. Fortunately, the issue shouldn’t be too difficult to diagnose and even fix. 

First, check the spark igniter cap. It should be 1/8-inch. If it’s larger, the heater will refuse to ignite for safety reasons. If the size isn’t the issue, check whether the gas valve is connected to the gas pressure switch.

Some propane heaters are designed this way to boost safety. The design requires that the gas supply pressure meets minimum standards. You also need to purge air out of the gas supply line. Otherwise, the heater may refuse to ignite. 

If you’ve fixed the above issues, but the unit still won’t ignite, it’s time to check whether the board is in working condition. To do so, check for 24-volt wiring at the valve. If 24 volts are missing, the board is damaged and needs replacement. If they’re present, the transformer is damaged or too weak to handle the load. 

5. The Heater Lights but doesn’t Stay Lit. it Constantly Goes into Lockout (LED Produces Two Flashes)

If your garage heater lights well, remains on for several seconds, then goes into lockout, your mind should instantly think about the flame sensor and air supply. 

Let’s begin with air supply. Your gas heater runs on oxygen drawn from atmospheric air. However, there’s a slight twist. Most gas heaters are designed only to work if there’s sufficient air supply. If it picks up signs of poor air circulation within the room, it will refuse to work. Usually, it will go ON, then off within seconds.

The easiest way to solve this problem is by unblocking the air supply into the house, especially around the heater. 

If the airflow is good, check the flame sensor. The flame sensor is a tiny safety feature on your gas heater that detects the presence of a flame. It generates a small electric current that returns positive feedback if a flame is present and negative feedback if no flame is detected.

If it returns positive feedback, it signals for proper gas release, and regular heating ensues. However, if no flame is detected, it signals for automatic gas cut-off. Thus the unit goes off within a few seconds. 

However, the flame sensor itself can malfunction. If this happens, it will not be able to return positive feedback. Thus, the heater will go off within seconds even if a flame is present. To fix the issue, find out if the sensor is cracked or grounded. Also, check the sensor wire for continuity and verify that it produces at least 6.0 microamps. 

6. The Heater Fires Up, but the Fan Motor doesn’t Come ON, Causing the Limit to Open (LED Flashes Four Times)

When this happens, you may immediately conclude that the motor has malfunctioned. However, although that’s also a possibility, the motor may fail to come ON for several other reasons, such as improper connections.

The first to consider is checking whether there is 120V at the ACC terminal on the control board. This is the wire that provides power to the board and, by extension, the motor. If it’s not present, then your control board is compromised and may need repair or replacement. You need a professional technician in both cases.  

However, if the 120-volt circuit is present, it’s likely an issue with the motor itself. The blower motor is a motor within the unit’s blower system that helps blow the heated air out of the heater and into your home. 

It can fail for many reasons. For instance, maybe the wires are damaged or disconnected. You mainly want to ensure that the fan motor neutral wire is connected to the supply voltage neutral. Otherwise, the motor won’t run. Other than that, the motor may fail as a result of constant wear and tear.  

7. The Upper Rollout Limit Keeps Tripping (Four LED Light Flashes)

The rollout limit switch is a safety feature on nearly all gas heaters that probes temperatures mounted to the metal plate. 

It has two primary functions. First, it tells the blower fan when to turn ON and OFF. It does so by sensing supply air temperature and signaling the fan to turn on when air is heated to heat your home.

Secondly, it closely tracks supply air temperature to detect and prevent overheating. If overheating is detected, the limit trips, effectively shutting down furnace operations until you intervene. 

If you notice that the limit switch trips too frequently, you may have a dirty flame sensor, overheating, or a faulty limit switch. As we discussed earlier, the flame sensor is a safety feature that verifies the presence of a flame before allowing full heating.

A dirty sensor cannot correctly detect a flame, thus may cause the rollout limit switch to trip. As a result, you may need to clean or replace the switch. 

Tripping due to overheating is straightforward. If the switch detects overheating, it will trip to protect the heater’s interior components and prevent fire. In this case, you may have to fix the issue causing overheating before you can use the heater. 

Finally, the rollout limit switch can become damaged or compromised. For instance, after many years of reliable service, the limit switch can activate lockout mode, rendering the heater locked until you replace the switch. 

Here is garage heater horizontal venting guide


Though tough and versatile on the outside, Beacon Harris garage heaters are complex and delicate inside as they comprise multiple micro components that work together to keep your home warm.

That’s why the user manual always asks for utmost care when operating the heater. Additionally, you must maintain it appropriately as described in the user guide for a long life of reliable use. 

However, you now know how to diagnose and fix the seven most common issues in case of malfunction.