Tip & How-To about Heating & Cooling

How do I Set the Thermostat Anticipator

If you have an older thermostat that has a heat anticipator in it then there are some things that you need to know about setting it and what it actually does.

First the function of the heat anticipator is to fake the thermostat into feeling the room temperature as hotter than it really is. The heat anticipator is actually a variable output heater inside your thermostat. The amount of heat that it actually produces is very, very small. This heat does, however, make a difference in how the room temperature feels to your thermostat.

If no extra heat is made inside the thermostat it will not react quickly enough to shut off the heating source. This will make the room “overshoot” the set point of the thermostat.
By heating the thermostat up very slightly it then shuts down the furnace or heat source before it actually reaches the temperature set point. This will allow the left over heat to go into the room and raise the temperature to the set point by the time it is all used up.

If you are experiencing wild temperature swings or the room temperatures are either not getting to the set point or going over the set point then the heat anticipator either is not adjusted right or it is burnt out and not working at all.

There are a couple of different types of heat anticipators. They will usually look like one of these.



If your heating is running too long then you will need to adjust the setting to a lower number. If you are not getting enough heat then go to a higher number. All you are changing when you do this is the amount of the heat coil you are using. Make small adjustments to the anticipator and then give it at least a half day before making more adjustments. Small changes can have a big effect if the heat anticipator is working correctly.

You also can set the anticipator by checking the current draw of the system. To do this you need to use an amp meter and measure the current draw of the heating unit when it is running. Then set the heat anticipator to the corresponding number of the current draw. This will at least get you a good starting point and some fine small adjustment can be made from there.



For more advanced digital thermostats there are cycle change features that do what this heat anticipator does in older thermostats. These often incorporate many things in determining the cycle length of the heating. These thermostats will not have a heat anticipator setting.

Like many things when it comes to your comfort, all people feel things a bit differently. You need to make the changes to the thermostat so that YOU feel comfortable. There is no right way it has to be done. Make it work for you and adjust the thermostat so that you are the most comfortable!

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http://www.fixya.com/support/r3623083-thermostat_wiring_terminal_designations

http://www.fixya.com/support/r3584298-air_conditioning_programmable_thermostat

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furnace repair


If the thermostat is an older model it may have the heat anticipator on the thermostat set incorrectly. It should be set to the measured amp draw from the "W" terminal on the thermostat.

Apr 30, 2017 | Heating & Cooling

1 Answer

what should the heat anticipator be set at on the thermostat?


The purpose of a thermostat heat anticipator is to "de-sensitize" the thermostat so that when actual room temperature is hovering close to the set temperature on the thermostat, the thermostat switch won't keep switching the air conditioner or heating system on and off too often - which can damage the equipment.

If you are replacing an existing defective thermostat with a new one, simply, set the anticipator to the same setting as the old one- as long as they are of the same manufacturer and model.

If you don't have the old one to match the new thermostat settings to, then you need to measure the thermostat's circuit using an ammeter.

In order for the thermostat to operate properly- you must adjust the heat anticipator resistor to match the current of the gas valve or relay on an oil-fired burner..

Another option is to install the T-stat using the factory default setting.
Since you did not mention the make and model number of the T-stat you are using, I cannot be more specific.

Feb 12, 2017 | Heating & Cooling

1 Answer

Bryant Furnace starts up then shuts off


If you have a standard thermostat and not a digital stat, the problem could very well be the 'heat anticipator' setting on the thermostat sub-base. It is a variable resistor that has to be adjusted to match the amp draw of the heating control circuit. In the heat mode, the heat anticipator 'warms' up the thermostat because of the heat generated through the system controls and causes the thermostat to 'anticipate' room temperature setpoint just a little before it really gets there.

If set too low, the result is a short cycle, if set too high, the result is an overshoot in setpoint temperature. The average setting for the anticipator is .4. You should see a very thin 'wire wound' flat resistor under the cover with a thin metallic pointer that physically slides from left to right or right to left. The pointer is pointing to its 'setpoint'. Adjust it up .1 or .2 from its current setting and observe operation for a week or so to see if any appreciable change has occurred.

Mar 22, 2015 | Bryant Heating & Cooling

2 Answers

How do I adjust the heat anticipatory to its proper settings


Look on the gas valve. Or post the make and model

Mar 21, 2013 | Heating & Cooling

1 Answer

my themorsat stop working,and I replaced the batteries.


see this causes and fix it. God bless you

Furnace Produces No Heat Possible Causes


Possible Repairs
  • Remove cover of thermostat and loosen screws holding unit to wall. Level the thermostat. Re-tighten screws and replace cover.
  • To adjust the heat anticipator, please see Heat Anticipator Adjustment.

  • Furnace Turns On and Off Frequently ("short cycling")Possible Causes
  • Dirty thermostat components
  • Heat anticipator not set correctly.


Possible Repairs

Sep 30, 2012 | Honeywell Programmable Thermostat Heater

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