Alarm.com Smart Thermostat Troubleshooting

[tyler (Tyler G)]

A variety of potential troubleshooting issues can arise when working with thermostats. Many topics are covered below, separated by device type.

Understanding reported behavior

Common problems with heating:

• Heat does not turn on
• Heat turns on, but the system is not heating
• Heat pump is not running
• AUX heat is not working
• Problem with the fan

Common problems with cooling:

• Air Conditioner is not turning on
• The A/C turns on, but the system is not cooling
• Heat pump is not running
• Problem with the fan

Common problem with fan:

• The fan is not running
• The fan is turning on too early
• The fan is turning on when the heat comes on
• The fan is not turning on when heat comes on

Identifying system type

Is it a Heat Pump or Conventional (Normal) system?

A heat pump is a standalone unit typically located outside of a home or on the rooftop of a business. Locations may vary. What makes a heat pump unique is that it can provide both heat and cool based on the position of its reversing valve. What makes it difficult to identify is that it looks exactly like an AC unit. Below are some ways to determine if the outdoor unit is a Heat Pump or an AC Unit.

Expected wires for a Conventional (Normal) system

• R or RH/RC - relay to close electrical circuit to control board
• Y and Y2 - operates condenser for air conditioning stages
• W, W2 - Heating stages
• G - operates fan

Conventional (normal) systems include: furnace, boiler, steam or hot water radiator, radiant in floor heat.

Expected wires for a heat pump

• R or RH/RC - relay to close electrical circuit to control board
• Y and Y2 - operates condenser of Heat Pump systems
• W, W2, Aux, E - auxiliary and emergency heating stages
• O or B - One required to operate reversing valve (most commonly O). The largest manufacturer of Heat pumps with B wire is Ruud and Rheem, and they are rarely used.
• G - operates fan

Heat pump systems include: air source, geothermal.

[tyler (Tyler G)]

Pre-troubleshooting steps

1. Check the thermostat locally to eliminate communication between the thermostat and panel or the panel and Alarm.com as variables.
2. Check that the mode is correct and that the target temperature (setpoint) is above the ambient temperature when testing heating and below the ambient temperature when testing cool. Verify that the difference between the temperatures is greater than the swing setting by at least one degree.
3. If the system had worked previously, determine what has changed.
4. Verify the thermostat and HVAC system have power.

Important: If using a Smart Thermostat HD, verify there is an RH and C wire, as both are required for power. The R wire must be inserted into RH.

Basic troubleshooting

Thermostat will not power on

If the thermostat will not power on, usually this is due to incorrect wiring or low batteries. It is recommended to insert high-quality batteries into the ADC-T3000 and ADC-T2000 in addition to using a C wire for power. The ADC-T3000 uses two AAA batteries, while the ADC-T2000 uses four AA batteries.

The Smart Thermostat HD requires both RH and C wires to provide power to the thermostat. If there is only one R wire present, connect it to RH. Connecting it to RC will not work.

Note: If the Smart Thermostat HD has only an RH wire, it will internally jump RH and RC.

Thermostat is not enrolling into the Z-Wave network

The Alarm.com Smart Thermostat (Smart Thermostat HD, ADC-T3000, and ADC-T2000) should be enrolled into a Z-Wave network following the instructions outlined here

Z-Wave devices may experience difficulty enrolling into a network for multiple reasons. If the Alarm.com Smart Thermostat is not enrolling into the network, see this page here.

Note : The 2GIG GC2e panel requires firmware version 1.22+ to successfully enroll an ADC-T3000 into its Z-Wave network.

Thermostat does not appear on the Alarm.com Website or mobile app

If the Alarm.com Smart Thermostat does not appear on the Alarm.com Website or mobile app after enrolling wait about 10 minutes then log out of your Alarm.com account and back in to update. If the device still does not show up, let your service provider know.

Listening for clicks

When the Smart Thermostat HD and ADC-T2000 turn a component on or off, a relay closes or opens, and an audible click can be heard. The click can be faint or hard to hear in loud environments.

To properly listen for clicks, change the thermostat to off mode. Change the thermostat to heat or cool mode and increase (for heat) or decrease (for cool) the target temperature until it is well above (for heat) or below (for cool) the ambient temperature of the room. Verify that you are far enough past that the swing setting is not a factor (i.e., swing is set to .5-degrees by default, so go at least three degrees above the ambient temperature). Shortly after, you should hear the clicks.

A thermostat clicking means that it is opening or closing relays. If you turn the thermostat to heat or cool modes and set the temperature high or low enough (respectively), and it clicks, it means it is trying to activate the heating or cooling system.

Note: The ADC-T3000 does not click when closing relays.

Compressor delays

Compressor delays will affect when components are energized, so the clicks won’t happen until the delay has expired. Any call for cool, and calls for heat with a heat pump system, will be subject to a compressor delay (default 5 minutes).

Important: After turning the system to off mode, don’t change it to cool or heat mode until the full five-minute delay has expired.

Jumper

Smart Thermostat T40K-HD

If there is a single R wire, always connect it to the RH terminal, as the Smart Thermostat HD requires an RH and C wire to power on. If there is only an RH wire, the thermostat will create an internal jumper between RH and RC.

Important: Do not put a physical wire jumper between RH and RC for the Smart Thermostat HD, as this will cause damage to the terminal and result in unexpected behavior.

ADC-T3000

If there is an R wire, connect it to either RC or RH and make the appropriate selection when asked which terminal is in use. This will create a digital jumper to the other R terminal that is not selected.

Example: Selecting RC only creates a digital jumper to RH.

If there are both RC and RH wires, a jumper is not needed. Select that both RC and RH are present during configuration.

ADC-T2000

The thermostat jumper is located on the bottom left side of the terminal board. This jumper bridges a connection between RH and RC. RC is used to power the right side terminals (C, Y, Y2, G, O/B) and RH powers the left terminals (Z, W2, W). Most systems today only have a single R (power) wire, so we plug the R wire into either RH or RC and bridge the connection between them, so that all terminals will receive power from this single wire. Without the jumper, only the RH or RC side will receive power. Some older systems have two different R wires - one for RC, and on for RH. In this case, we need to remove the jumper so that the left and right terminals are independently powered.

Caution: Failing to remove the jumper will short out the system after some period of time.

Available wires	Where to put them	Remove jumper?
R	Either RC or RH	No
RC	Either RC or RH	No
RH	Either RC or RH	No
RC and RH	RC > RC, RH > RH	Yes

[tyler (Tyler G)]

Possible Smart Thermostat failure scenarios

The below sections cover trouble points specific to each device:

ADC-T2000

Alarm.com Smart Thermostat ADC-T2000 - Installation Guide

Troubleshooting Heating or cooling doesn’t turn on when the set point is above or below the room temperature To prevent damaging the compressor, the thermostat inserts a delay when cycling the compressor. If the system should be on and it’s not, then change the set point to be 2 degrees beyond the current set point and wait 5 minutes to see if the system turns on. If not, contact a local HVAC professional. Heat pump is “Cooling when it should be heating” or “Heating when it should be cooling” S…

ADC-T3000

Alarm.com Smart Thermostat ADC-T3000 - Installation and Operation

Troubleshooting Heating or cooling does not turn on when the set point is above or below the room temperature To prevent damaging the compressor, the thermostat inserts a delay when cycling the compressor. If the system should be on and it’s not, then change the set point to be 2 degrees beyond the current set point and wait 5 minutes to see if the system turns on. If not, contact a local HVAC professional. Heat pump is “cooling when it should be heating” or “heating when it should be cooling” S…

ADC-T40K-HD

Alarm.com Smart Thermostat HD ADC-T40K-HD - Installation Guide

Troubleshooting Heating or cooling does not turn on when the setpoint is above or below the room temperature To prevent damaging the compressor, the Smart Thermostat HD inserts a delay when cycling the compressor. This delay is only a few minutes long. How To Resolve: Change the setpoint to 2 degrees beyond the current setpoint and wait 5 minutes, at which point the system should turn on. If this does not work, contact your local HVAC professional. Heat pump is “cooling when it should be heati…

[tyler (Tyler G)]

Advanced troubleshooting

If heat is not working:

1. Verify the setpoint and ambient temp at the thermostat (remembering the swing setting).
2. Understand the system. Where should the heat be coming from (forced air vents, or radiators/floor/baseboard)?
3. Check the jumper. For more information, see Jumper.
4. Check connections. For more information, see Wiring troubleshooting.
5. Verify you are not in Compressor Delay timeout.
6. If it is a forced air system, try setting the thermostat’s Heat Type to Electric to Verify the fan is getting switched on.
7. Listen for clicks. For more information, see Listening for clicks.

Is it cooling or just running the fan without heating or cooling?

Type of system	If cooling:	If running the fan without heat or cool:
Heat pumps	1. Verify the configuration of the reversing valve (O/B terminal), as it could be backward (heating when calling for cool, cooling when calling for heat). 2. Verify the Y wire is not loose/wrong terminal.	1. Verify that the Y terminal is activated/wired properly with a digital multimeter, listening to clicks, or manual test. 2. Check for no power to the terminal because of a missing jumper on the ADC-T2000.
Normal systems	1. Verify the HVAC system configuration, as it could be improperly set up as a Heat Pump, which would call the Y terminal, thus cooling instead of heating. 2. Verify the W wire is not loose/wrong terminal.	1. Verify that the W terminal is activated/wired properly with a digital multimeter, listening to clicks. 2. Check for no power to the terminal because of a missing jumper on the ADC-T2000.

If auxiliary heat is not working:

1. Verify the setpoint and ambient temp at the thermostat (remembering the swing setting).
2. Verify that this system has an Auxiliary heating stage.
3. Verify thermostat configuration, especially for heat mode, and verify it is configured for auxiliary heat.
4. Check the jumper. For more information, see Jumper.
5. Check W-wire connection, especially that it is not wired in W2 (i.e., that is for second stage of Aux, if present).
6. Verify you are not in a staging delay and that you have exceeded the heating differential
7. Listen for clicks. For more information, see Listening for clicks.

If cool is not working:

1. Verify the setpoint and ambient temp at the thermostat (remembering the swing setting).
2. Verify that this is not a Heat Only system.
3. Check the jumper. For more information, see Jumper.
4. Check connections. For more information, see Wiring troubleshooting.
5. Verify you are not in a Compressor Delay timeout.
6. Listen for clicks. For more information, see Listening for clicks.

Is it heating or just running the fan without heating or cooling?

Type of system	If heating:	If running the fan without heat or cool:
Heat pumps	1. Verify the configuration of the reversing valve (O/B terminal), as it could be backward (heating when calling for cool, cooling when calling for heat). 2. Verify the Y wire is not loose/wrong terminal.	1. Verify that the Y terminal is activated/wired properly with a digital multimeter, listening to clicks, or manual test. 2. Check for no power to the terminal because of a missing jumper on the ADC-T2000.
Normal systems	1. Verify that the Y terminal is activated/wired properly with a digital multimeter, listening to clicks. 2. Check for no power to the terminal because of a missing jumper on the ADC-T2000.

[tyler (Tyler G)]

Wiring troubleshooting

Basic wire checking

1. Verify the wires are stripped to the correct length and are inserted correctly, making good contact with the terminal. If a multimeter is available, skip to Verify wiring with a multimeter below.
2. Tug on the affected wire to see if it is loose in its terminal.
3. Try removing the wire, check if it is stripped correctly and straight, then re-insert.
4. Sometimes is easier to depress the terminal release button lightly as you insert the wire.
5. If the issue is not resolved check out, continue to the section below on checking wires with a multimeter.

Verify wiring with a multimeter on an ADC-T2000

When checking the C, Y, Y2, G, and O/B wires:

1. Using the red probe, touch the metal pad behind RC (or RH if that’s the connected terminal).
2. Using the black probe, touch the metal pad behind the corresponding terminal you are testing (see Y in the diagram above).
3. Verify that you are getting between 18-30 VAC on the multimeter.
4. If you are getting 0 V, the RC wire is likely not connected, or the thermostat wires are not active.
5. If you are getting something slightly greater than 0 V, the terminal you are testing is not connected properly.
6. Remove the problem wire, re-strip, re-insert, and test again.

When checking the Z, W2, and W wires:

1. ​​​​Using the red probe, touch the metal pad behind RH.
2. Using the black probe, touch the metal pad behind the corresponding terminal you are testing (see Y in the diagram above).
3. Verify that you are getting between 18-30 VAC on the multimeter.

• If you are getting 0 V, the RH wire is likely not connected, or the thermostat wires are not active.
• If you are getting something slightly greater than 0 V, the terminal you are testing is not connected properly.
• Remove the problem wire, re-strip, re-insert, and test again.

Fan troubleshooting

Basic troubleshooting

1. Verify the setpoint and ambient temp at the thermostat (remembering the swing setting).
2. Verify that this is not a Heat Only system and that it does have a fan.
3. Check thermostat configuration, especially for heat mode.
4. Check the jumper. For more information, see Jumper.
5. Check G-wire connection.
6. Verify you are not in a Compressor Delay timeout or downtime Fan Duty Cycle.
7. Listen for clicks. For more information, see Listening for clicks.

The fan is turning on too early

This is likely due to an improper thermostat configuration. Some heating systems will turn on the fan without the help of the thermostat, and build in a delay to allow the furnace to heat up.

Fan turns on when the heat turns on but is not supposed to do so

This is also due to improper configuration. Switch the heat type configuration from fossil to electric.

The fan is not turning on with my heat when expected

1. Verify that the system is forced air and not radiator heating (even though the A/C is forced air) to see if the fan should even be running during heat. Determine if the site has radiators or baseboard heating.
2. Please verify that the G wire is connected properly.
3. Check the jumper. For more information, see Jumper.
4. Verify the setting Heat Type is set to Electric and verify the setting is synced correctly with an updated timestamp.