Fan-On Energy Savings

How the “Fan-On” position can actually save money.

Energy efficiency is an interesting term. Often people associate it with simply using less electricity, but really it’s not about that at all. It’s about effectively converting energy into work. Sacrificing the amount of work performed to save energy is not greater efficiency.

For example, I once lived in an apartment that had an in unit washer and dryer. The dryer was a new “high efficiency” model that claimed to dry your clothes using nearly half the electricity of a standard dryer. Sounds great at first, the problem was that it was only about half the size of a standard dryer and said right on it that it could only handle a half load meaning you would have to run it twice to do a full load. Also it didn’t even do a half load very well. We would often have to run it 2 or even 3 times to get our clothes mostly dry (this was in central Florida so clothes were never fully dry anyway). We and many of the other tenants of the complex complained about the poor quality of these new dryers. The owners said that they would save us money in the long run and we would be grateful for them even if it took a little longer to dry our clothes. But they did not save us money, in fact most saw increased bills. We stopped using ours completely and either went to the Laundromat down the street or attempted to hang dry our clothes (does not work well in central Florida). In the end I learned that using less electricity is not the same thing as increased efficiency.

Sadly In the HVAC industry I see the same problems. Many focus on energy savings and forget about comfort. The problem is when people are uncomfortable, they are going to adjust the thermostat to whatever is required, for them to be comfortable. At this point the so called “energy savings” disappear. 

Here at FanHandler we have found a way to create real energy savings and truly reduce electric bills by making people more comfortable, not less. We have found that these energy savings come from an unlikely place. Ladies and gentlemen, I introduce you to the “Fan On” position.

For years, many have known about the comfort and indoor air quality improvements that come with the constant air circulation of the fan on position. The main problem is that it causes what engineers call a “parasitic use of electricity”. Engineers have concluded that when it comes to using your furnace in the fan on position, the costs outweigh the benefits for most of the population. As a matter of fact, there are countless articles written on why you should not use this forbidden “Fan On” position and a lot of math showing just how much electricity and money you are throwing away if you do. And they are right. I am not here to disprove or dispute their findings. However, here at FanHandler we believe that constant air circulation can be done right, and actually save more money than using your system in “Auto”.

You see there is something known as the “fan laws” that has helped us to find the solution.

The fan laws state that if you decrease the speed of the fan by ½ you decrease its energy usage to 1/8. This is pretty well known throughout the industry and many systems are now decreasing the speed the fan speed to 800 or 600 rpm when in the fan on position in an effort to reduce the electricity consumed by the constant blower. This gives significant savings over using the fan at full speed, and has the added benefit of reducing the noise of the constant blower and even making the air filters work slightly better because they are not blasting the germs and dust particles right though the filters. This is a good improvement but, it’s still considered by many to be a waste of electricity. And to some degree they are right. You will not save electricity by running the fan constantly even at 600 rpm. However here at FanHandler we have found that if you continue reducing the speed of the fan there is a switching point where the improved comfort brought by the continuous fan actually outweighs the cost of running the fan.

The Department of Energy's Energy Savers website says that homeowners typically save 3% on their heating bill for every degree that they turn down the thermostat during the winter. In other words this tells us that comfort is a factor in the energy efficiency equation. After all making people comfortable is what furnaces were designed to do in the first place. If we as HVAC professionals can make the home comfortable enough that homeowners don’t need to have the thermostat set as high in the winter, or as low in the summer, then we are saving the home owner money and truly making the whole system more energy efficient.

Constant air circulation has proven to make homes more comfortable. It does this by eliminating the hot and cold spots in homes and keeps an even temperature from room to room and even more importantly, from floor to ceiling. When we put the “comfort factor” in to our calculations, that is the 3% energy saving per degree, it’s easy to see that in real world conditions, constant fan can save a significant amount of energy.

Here at FanHandler we have done real world testing not just laboratory testing to determine that the sweet spot for the fan speed is about 300 RPM. At 300 rpm you are now using only about 1/60th the amount of electricity. With high efficiency ECM blower motors, that's only about 12 to 15 watts. That’s one forth the power consumed by a standard light bulb. We have found that at this speed there are many benefits. Including:

  • Completely silent operation (Even standing right outside the air handler you cannot hear that the fan is running).
  • Vastly improved air quality(especially for things like UV lights and electronic air cleaners)
  • Increased motor life(when the fan never shuts off it’s see significantly less ware from the usual banning on and off).
  • And of course energy savings.

Now here is the part you have all been waiting for. The Math(okay so maybe just us nerds have been waiting for this, but here it is anyway).

According to EIA In 2018 the average cost of electricity in the US was around 13 cents per Kilowatt hour. In other words if you were to use 1000 watts for one hour it would cost you 13 cents. So at 15 watts continuous use for a month you would use a total of

15 Watts x 24 Hours x 30 Days = 10800 watts or 10.8 kilowatts costing a total of $1.40 cents.

Now, during the colder months your furnace runs about 30% of the time anyway. So you reduce that figure by 30% giving you an increase on your electric bill of $0.98. That’s less than a dollar a month for using the fan on position at 300rpm.

Now as we have seen from studies and from the reports of our own customers. With continuous air circulation homeowners are just as comfortable at a thermostat setting 3 degrees lower than it was during intermittent operation. Remember there is a savings of 3% per degree so at 3 degrees that is 9% savings on average. The heating bill for a typical home in the US is $200/month during the heating season. 9% of $200 is $18.00. Minus the $0.98 you have a total savings of $17.02 just for using continuous air circulation.

In addition to that if you factor in higher efficiently of an ECM blower motor during a heating or cooling cycle, and ECM Modulator kit can save a significant mount over a standard PSC setup.

And there you have it. When constant air circulation is done correctly the “Fan On” position can actually use less electricity than “Auto”. And as we have found, in many cases it does.

FanHandler installation

FanHandler Inc. 1443 45th Ave, Salem OR 97301

For use only on P.S.C. or shaded pole motors used to drive direct-drive fans, blowers and pumps.

LOW VOLTAGE SENSORS FOR 120, 240 and 277 volt FanHandler and ZoneHandler CONTROLS


120-15, 240-8 AND 277-8 ARE  SUPPLIED WITH 1-RED SENSOR (heating) OR 1 BLUE SENSOR (cooling)



Ohm values @ 77°: Red = 30K, Blue = 5K, Yellow = 5K


FanHandler controls are ETL listed for field or factory installation under file #114704-322 as conforming to ANSI/UL-508 and CAN/CSA C22.2 NO. 14.  Installation and wiring must comply with all local and national electrical codes. Only qualified HVAC technicians and service mechanics may install or adjust the FanHandler motor speed control. To do otherwise will void all warranties.


  2. Check operating voltage of fan, and make certain that the control is of the proper voltage and type.
  3. Mount the FanHandler in a location safe from weather, moisture or excessive heat.  Normally this is inside the fan compartment, mounted on or near the blower.
  4. . Locate sensors in the SUPPLY Duct were they will sense a representative sample of the air temperature being delivered to the conditioned space.  This is done by drilling a 1/2” holes in the proper locations and fastening sensors to duct with two sheet metal screws each.  Do not locate sensors a long distance down the duct from the heating and cooling source, and do not mount them right up close to the heat source or the a/c coil. This may result in inconsistant  fan speeds.  Route low voltage  sensor wires (usually thermostat wire) away from high voltage wiring. Wire sensors to corresponding colored sensor wires (blue sensor to blue wires, red sensor to red wires and yellow sensor to yellow wires).
  5. Wire the FanHandler in series with the fan motor. The recommended placement is in the common wire from the motor.
  6. Double check wiring, then reapply power to the system.
  7. Determine mode of operation. The FanHandler and ZoneHandler controls can be operated either with the sub base to AUTO for intermittant fan operation, or to FAN ON for continuous operation.
  8. Set minimum speed. In many cases it is not necessary to adjust the minimum speed. However, if you want to adjust the minimum speed, it is done by turning the small screw on the blue rectangular potentiometer that is next to the fuse holder at the top of the control. This is a 25-turn pot with a clutch at both ends, so you won’t break it from over-turning. Turning the pot clockwise increases the minimum speed, and turning the pot counter clockwise lowers the minimum speed.  Set the minimum speed as high as possible, without causing uncomfortable drafts. Setting the minimum speed too low (although impressive) does not properly mix the air in the home and will produce unwanted results.  A rule of thumb: set minimum speed so that the furthest run will move a tissue but not cause a draft a foot from the register.  The minimum speed adjustment is for setup and fine-tuning only, it should be set and left alone.  If the owner wants to temporarily override or change the speed of the fan after installation, then a remote speed selector should be installed (see later in the instructions).  That way your original setting is maintained while allowing the customer to override the speed as desired. 
  9. Verify operation. Allow the system to balance out so it is delivering about 72° and is neither calling for heating nor cooling.  Then set the thermostat to call for heat, as the temperature rises in the duct, the fan speed should increase.  Set the thermostat to shut the heat off and observe that as the delivered air temperature drops, the fan speed will decrease to your PRE-SET minimum speed. Then set the thermostat to call for cooling, as the temperature in the duct drops the fan speed will increase and hit top speed at about 50° delivered temperature.  Turn thermostat up turning off the air conditioner.  Observe that while the temperature in the duct approaches room temperature, the FanHandler control will smoothly decrease the fan speed back to your minimum speed setting.

ALL FanHandler and ZoneHandler

Controls have the same configuration for minimum speed setting.

FH MinSpeed


Only the #14 black wire (line in) and the #14 red wire (line out to motor) operate the motor. The blue wire is used to eliminate radio frequency noise, and the green wire is for ground. These controls can be installed in the hot (L1) or the common line (or L2). FanHandler controls can be used on any speed tap or switched between speed taps. They can be switched on and off or run continuously. The low voltage #18 wires located next to the ETL label are connected to the sensors and can be extended by using low voltage thermostat wire.


     Branch Line Protection

All 120 volt models are rated at 15 amps, 60 Hz maximum. All 240 and 277 volt models are rated at 8 amps, 60 Hz maximum. It is the installer’s responsibility to provide branch line circuit protection to the FanHandler circuit of no more than 15 amps. (usually the equipment fusing will qualify for this requirement).




For electrical safety and correct operation, be sure to properly ground the entire furnace and air conditioner system, including associated devices and the FanHandler.  Devices such as electronic air cleaners, spark ignitors, etc. if not properly grounded will cause “motor  bumping”.  Improper grounding of the FanHandler control and motor may result in AM band radio noise.




·        MOTOR STAYS AT HIGH SPEED - Minimum speed adjustment set too high. Control bypassed by relay or switch. Wires leading to the cooling sensor (this is the most common reason) are open. Heating sensor wire or sensor shorted. Sensors mixed.

·        MOTOR STAYS AT LOW SPEED -      On heating, the heating sensor or wire open. On cooling, the cooling sensor or wire shorted. Red heating sensor measures about 30K ohms @ 78°. Blue cooling sensor and yellow heating sensors measure about 5k ohms at 78°. These sensors are much more accurate than the average service ohmeter.


·        MOTOR GROWLING OR BUMPING - Incompatible motor,  poor grounding of equipment. Sensors shorted to ground.


If you or your customer is unwilling to replace an incompatable motor, we recommend that you not purchase or install FanHandler controls. Equipment manufacturers have been using higher quality motors lately. We suspect that this is because of extended warrantees. If you install a number of FanHandler controls, you will encounter poor quality direct drive fan motors. These motors may be built to meet a price criteria rather than a quality specification. These motors do not contain adequate  copper windings or iron laminates to allow the motor to follow the fan laws when reducing speed. These motors are usually constructed with loose stator to rotor spacing tolerances. Or a motor on the job might have been banging on and off for years and not serviced, so the bearings are worn. If a motor heats-up and/or growls at low speed, it should be replaced with a high quality motor designed for general use. 


Quality is the only factor in determining a motor’s fitness for speed regulation. Determine motor fitness on a case by case basis. It is impractical for us to keep up with changes that equipment manufacturers make in the motors that they install. Baldor (the big dog of industrial motors) is building high quality, commercial/industrial quality, motors to our specifications. We offer these motors to FanHandler contractors only at very affordable prices. I.e. We aren’t making money on them. You will not know what a super high-quality motor is, until you have experience with a Baldor motor!

·        RADIO NOISE - Improperly grounded motor or HVAC system.

·        MOTOR STAYS OFF - Power off to motor (circuit breaker, fuse, or fan compartment switch, open).






FanHandler LA models are used to control refrigerant head pressure. They are basically wired the same as the other models. The only difference is that the sensor is located in the air stream leaving the condenser coil or  attached to the liquid line (recommended best) just as it leaves the condenser. Use insulated black tape which works very well. Protect the control box from the weather by installing it in the control compartment or using a weather-tight box.  Set the minimum speed so that the condenser fan is able to turn when power is applied to motor. LA controls are aoften used to control the speed of the circulating pump for head pressure control in water source heat pump applications. This is also a very useful tool to use when setting refrigerant charge in cold weather. It beats “tenting” by a long shot.









FanHandler1 400x81ZoneHandler 587x132 shadows



We’ve tested these, and have NEVER seen a better motor.

Whisper Quiet, responsive, super energy efficient & Country-boy strong

We’ve even run one for three weeks at about 100 rpm. It is cool and super quiet even at that speed!!!!

Industrial/commercial quality, ball bearings, electrically reversible, 48 frame, 1075 rpm, 3-speed, 50° rise,super quiet, super high efficiency. Just like FanHandler, Baldor does not cut corners.

Blower motor quality varies greatly. Indicators of unacceptable motor quality are: loud growl at low speed, overheating and amp draw that doesn’t drop as motor speed decreases. A motor may have been banging on and off for several years and, because of bearing wear, the rotor is no longer aligned with the stator and other motors were just built that way. All motor manufacturers know how to build high quality/high impedance motors. We are confident that market forces govern their quality decisions.

Equipment manufacturers are not obligated to install motors to meet our standards. Some manufacturers are installing very high quality motors and some are short on copper windings and iron laminates. We stopped trying to keep up with who’s installing what motor.

Several years ago, we got fed-up with being blamed for poor motor performance associated with speed control.

Our response to this is to make available the best quality motor we can find. Doing so, keeps us, and our customers, at the forefront of comfort, efficiency and quality.

We asked Baldor Electric (the big dog of commercial/industrial motors) to build a motor for the FanHandler and then tell us what it cost. We sent them several of our controls and they came up with the best motor we’ve seen. The cost was surprisingly low.

These motors are available to FanHandler customers only. These motors are not a profit item for us. (We make our money from FanHandler and ZoneHandler control sales.) We are pleased to make these motors available to our customers who use one with each control for the best possible results from their installations or have run into a motor that doesn’t perform to expectations.

These motors are only available to FanHandler customers.                                                                                                           

FanHandler Inc - Salem, OR





ALL FanHandler and ZoneHandler

Controls have the same configuration for minimum speed setting.



 For printable PDF intructions please click here
ecModulator 600x132 shadows
All electrical work must be done with the power off by
trained HVAC technicians and to all governing codes.
ECM4 pinout


ECM Motors

  • ECM motors are designed for continuous operation
  • ECM motors should not be turned on and off by by switching the line voltage to the motor.
    They should only be activated by switching the low voltage to the ecMModulator.
  • The motor’s high voltage supply terminates in a five position (socket) plug that plugs into the motor’s 5-pin socket.
  • The 3-prong plug at the opposite end from the high voltage wire is ready for 115/120 vac (standard household current) voltage.
  • For higher voltages, see the instructions below.
115/120 Volt
ECM Wire3
The high voltage cord and 5-pin plug
are configured for 115/120 volt applivation.
208/230 Volt
For 208/230 volt application,
cut the Yellow wire as shown. Then
wire nut the ends of the wires. Next,
tape over the wire nuts to further secure
ECM CutWire
ECM WireEnd
When using the high voltage option of 208/230/277 volts to the motor, remove the 120 volt plug, expose the wire ends and attach the green wire to earth ground, the black and
white to L1 @ L2.
ECM Motor3
Plug one end of the low voltage
Pulse Width control cable into the
ecMModulator and the other end
into the motor’s 4-pin socket.
ECM Motor2


The following control modes are some of the obvious strategies that can be employed.
The ecMModulator can be used for a wide variety of applications and we can program the
ecMModulator to suit a wide variety of specialized applications.
Adjustable speed
Before getting into the different modes available for the ecMModulator, you might want to get an overview of the basic operation by viewing this video.
In this mode, and most other modes, the temperature sensor is mounted in the delivered air. In all cases, you are trying to get a well mixed sample of the air that is going into the building. Usually high up in one of the trunk lines and close to the plenum will give you a good sample. From there, the ecMM odulator response is: With no heat or cool and delivered air between about 62° and 80° the blower will be at the (adjustable) minimum IAQ speed. You can set this minimum speed from super low (say 100 rpm) to close to full speed. When the burner, electric strip heater, hot water coil, etc comes on and the delivered air begins to warm, the blower’s speed will follow the temperature/speed line to the right. There is no way to blow a cold draft. Because of the immediate but smooth response, there is no way the heat can get ahead of the blower speed. When the heat turns off, the blower’s speed follows the same path down.


When the AC turns on, the coil gets cold very quickly. This allows the coil to latch on to the latent load. A couple seconds later, the sensor detects the cold temperature and ramps the speed faster. Because of the instant speed/ temperature response, it can’t slug. Because the compressor has a fixed capacity, and because the coil has latched onto the latent load first, and because the blower’s speed has not overpowered the coil’s latent capacity, the latent/sensible ratio remains weighted towards latent. The ratio will stay pretty much the same until the latent load decreases. On a new (high humidity) installation you will notice that the blower doesn’t reach full speed and the delivered air temperature seems a bit warm. However, when you put your gauges on, you’ll notice that the machine is running full capacity. When you look at the overflow it will be running water down the drain at a fast pace. The reason for this is that much of the compressor’s capacity is still working on the latent load. An example would be: with an indoor RH of 78% on the installation day with maybe 55° delivered air temperature. The next day it might be RH 65% with delivered air 53°. Pretty soon the system will be putting out pretty close to 50° and the RH will be in the low 50% range, This is a quick and rough explanation. This is the operation in all air conditioning modes. More on this later. When the compressor shuts off, The delivered air temperature rises rapidly, and the blower’s speed drops with the temperature rise. This process is quick enough to keep from blowing water off the coil. Thus it allows constant fan even in the muggiest climates. From that point on, the system takes full advantage of the refrigeration and latent capturing effect of pressure equalization.
Terminals 3 & 4 will accept a dry contact ( NO APPLIED VOLTAGE! ) From a humidistat, relay, or can be jumpered for permanent setting. By shorting between terminals 3 & 4 the (HUM SET) Humidity Set potentiometer allowes you to adjust the cooling temperature speed line. This can be done with a simple return air humidistat, room humidistat, relay, or they can be jumpered for special conditions. We recommend this be done only by highly qualified, experienced (a/c refrigeration) technicians. We do not recommend that this be done without first monitoring the installation for several days. We do not recommend that this be done without hooking up and watching the refrigerant gauges.
Terminals 7 & 8 can be shorted together to place the ecMM odulator into the heat pump mode. In this mode of operation, the heating temperature speed line is steeper so that the blower reaches top speed at 115°. The air conditioning is not affected and remains the same as in the other modes. When there is no heating or cooling, the blower’s speed is in the adjustable minimum (IAQ) speed. When the system switches to heat, the blower is loafing along at the adjustable minimum IAQ speed. This results in immediately building head pressure. Head pressure results in immediate heat. The system cannot blow cold. As the delivered air temperature increases, the blowers speed increases. Temperature and speed are locked together. This action can be compared to having a extremely high quality head pressure control operating the indoor fan. The result of this action is an average increase in delivered air temperature of about 15° and a significant lowering of the balance point and increased energy efficiency. 10% is common.
Setting Your Maximum Duct Pressure
On the ecMModulator 4 Z controls the HI SET pot is used to adjust the pressure limit. Turning the
pot clockwise will increase the maximum duct pressure and counter clockwise will decrease the
maximum duct pressure. 2 full turns will approximately equal 0.1" wc. ecMModulator 4 Z controls
are shipped with a factory duct pressure setting of about 0.3” wc. Before you begin setting the
pressure re-move the temperature sensor wire from the control (top terminal). This will drive the
blower up to and slightly past the present pressure setting speed. Wait while the blower’s speed
settles before changing the pressure setting. If you want to control from pressure alone, then just
remove the temperature sensor and leave it off. A step by step procedure for adjusting the
pressure is listed below.
1. Re-move the temperature sensor wire from the control to cause the motor to go full speed.
2. For a higher pressure, turn the screw on the HI SET pot clockwise.
3. For a lower pressure, turn the screw on the HI SET pot counterclockwise.
4. If the pressure is close to what you want, turn the pot slowly about a quarter turn at a time to
give the motor and control time to adjust. A rough calculation is that about two turns will change
the pressure about 0.1” wc.
5. When you are at or above the programmed pressure setting, the ZO light will be on.
6. If you overshoot the adjustment and wish to reverse the setting you made, you can figure that
it takes about 1/4 turn to take up the slack in the pot’s clutch before you will notice a change.
8 Once you achieve the pressure setting you want, reconnect the sensor wire.



Frequencey drive
All of the previously described features that are built into the ecMModulator control can be used to control frequency drives for large three-phase fans, pumps, or any equipment that accepts a Pulse Width modulation or 0 to 10vdc signal. There are a large number of applications for the ecMModulator. Some suggestions are: Control of parallel piped ECM pumps that feed mixing valves could accept the signal from building automation controls. This could save huge amounts of energy and do away with three way valves. Rooftop HVAC units located in facilities where they do not have building automation. Upgrading millions of rooftop gas packs. Control of terminal fan boxes. Control cooling tower fans to maintain steady temperature to large chillers. The energy saving, comfort producing list is endless.
FanHandler Inc. Dallas, OR 97338
 For printable PDF intructions please click here: ecMModulator_Installation.pdf

Sensor Placement

Trouble Shooting GuideecModulator 600x132 shadows

Problem:  Motor is not spinning



No Power to control

First check for lights on the control. If there are no lights, you are not getting power to the control. Use a multi meter to check for 24VAC at the input terminal.

Pressure limit set too low or pressure tube is crimped

(Model 4Z only)

Take note of which lights are on.  If the red ZO (zone) light is on there may be a crimp in the pressure tube or it is pinched somewhere. Check the pressure tubing and fix anything that looks like it maybe blocking the control from receiving proper air flow. If there is nothing obstructing the air flow to the control and the zone light is still on, the pressure limit may be set too low. Adjust it up by turning the high speed pot clockwise 1 to 2 full turns and see if the light goes off. If it goes off your motor should come on and begin to pick up speed.


Motor is not getting power

First check that the high voltage going to the motor is a constant voltage source capable of handling the current draw of your motor. Also check that the power connector is fully seated into the motor and that the yellow jumper on the power connector is intact for 120V operation and clipped for 240V operation. If 240V was applied to the motor with the yellow wire intact then your motor may be blown. Please contact FanHandler for a replacement.


Motor is not receiving  a signal from the control

You can check that the control is outputting a signal with a multimeter. Set the multimeter to the 20Vdc range and check for voltage across terminals 9 and 10. If the voltage measured is between 0.7Vdc and 10Vdc, the control is putting out a signal to the motor. Check that the control signal cable is properly seated into both the control and the motor. If the cable is properly connected and the motor still doesn’t spin, there may be a break in the cable. Check that you are getting a signal at the motor end of the cable with your multimeter. If you are getting a voltage less then 0.7Vdc your minimum speed is set too low. Adjust the minimum speed.



Problem: Motor spins but will not ramp up speed with temperature



Improper placement of temperature sensor

Check the temperature at the sensor to make sure you are getting the temperature that you expect. Remember the fan speed is proportional to the temperature seen by the control. The fan should start to pick up speed at 78 degrees on the heating side and 62 degrees on the cooling side.

Pressure setting too low

Check to see if the Zone light is on. If so, try adjusting the pressure setting. If the zone light is not on, it could be the control trying to limit the pressure (it’s just not quite fast enough for the light to come on). Try adjusting the HI SET pot clock wise.


Problem: Motor spins and picks up speed but not fast enough



Improper placement of temperature sensor

Check the temperature at the sensor to make sure it is getting an accurate temperature reading. On the heating side the fan will start to pick up speed at 78deg and hit top speed at 115deg in heat pump mode and 130deg in furnace mode. On the cooling side the fan will begin to pick up speed at 62 degrees and hit top speed at 54degrees. (For more details please refer to sensor placement guide).

Problem: Motor ramps with temperature but doesn’t react as zones open and close



Improper placement of the pressure plate

(Model 4Z only)

Make sure the pressure pickup plate is placed before all dampers and located in a part of the duct that has good air flow. You want to avoid places where there may be an air pocket; such as, right after a corner.  Check that the pressure tube is properly connected and not crimped or pinched.

Problem: Speed ramps up fine in heating but not fast enough in cooling



Improper placement of temperature sensor

Check the temperature at the sensor to make sure it is getting an accurate temperature reading.


If you are not using a humidifier or dehumidifier, you can adjust the cooling ramp with the humidity pot (HUM pot). First place a jumper across terminals 3 and 4. This will put the control into humidity mode. By default, the HUM pot is turned down about 9 turns for a speed drop of about 100 rpm. You will need to adjust this by turning the pot clockwise 9 full turns, to bring the ramp back to center.  From here you can continue turning the HUM pot clockwise to begin to raise the cooling ramp. Turning counter clockwise will lower the cooling ramp.

Problem: Speed ramps up fine in cooling but not fast enough in heating



Improper placement of temperature sensor

This is most likely a sensor placement issue. Check the temperature at the sensor to make sure it is getting an accurate temperature reading.  


If this is a furnace application and you want the control to ramp up faster in heating, you can set the control to heat pump mode. In heat pump mode the control will ramp up to full speed quicker on the heating side while leaving the cooling side unaffected.


Yellow Sensor Temperature To Resistance Chart

 yellow sensor temps

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