Alarm.com Smart Thermostat - Troubleshooting Guide

Safety first: Turn HVAC power off at the breaker before moving wires. Use a multimeter only if you’re comfortable—otherwise contact a licensed HVAC pro or True Protection.

Understand the reported behavior

Common heat issues

Heat doesn’t turn on / system not heating
Heat pump not running
AUX heat not working
Fan problems during heat

Common cooling issues

A/C won’t turn on / not cooling
Heat pump not running
Fan problems during cool

Fan-only issues

Fan not running
Fan starts too early
Fan on/off with heat incorrectly

Identify your system type

Conventional (normal)

Furnace, boiler, steam/hot-water radiators, radiant floor.

Expected wires: R / RH / RC Y / Y2 W / W2 G

Heat pump

Air-source or geothermal. Outdoor unit provides heat & cool via reversing valve.

Expected wires: R / RH / RC Y / Y2 W / W2 / AUX / E O or B G

Most heat pumps use O. Ruud/Rheem often use B.

Pre-troubleshooting checks

Test at the thermostat locally (rule out panel/cloud).
Mode is correct; setpoint is above room temp for heat / below for cool (beyond swing by ≥1°).
Did anything change recently? (wiring, equipment, power, filters)
Confirm thermostat and HVAC both have power.

Basic steps & quick wins

Z-Wave enrollment

Enroll via Add mode on the hub; then Menu → Settings → Network → Add on the stat.
GC2e requires firmware 1.22+ for ADC-T3000.

Clicks & delays

T2000 clicks when relays close; T3000 is silent.
Compressor delay ~5 minutes for cool (and HP heat). Wait out the delay before retesting.

Jumper logic

Stat	R wiring	What to do
ADC-T3000	Single R	Land on RC or RH; choose it in setup (digital jumper).
ADC-T3000	Both RC & RH	Select both in setup (no jumper needed).
ADC-T2000	Single R	Use physical jumper between RC & RH.
ADC-T2000	Both RC & RH	Remove jumper or you’ll blow a fuse/transformer.

Battery & screen

Flashing amber buttons + dark screen = batteries critically low → replace immediately.
Screen won’t stay lit indefinitely. Enable Motion Wake (AC power only).

Targeted fixes by symptom

No heat / not heating

Wait out compressor delay (HP); set 2°F beyond and retest.
Verify W on conventional; O/B config on heat pumps.
Set Heat Type to Electric to force fan (forced air).
Check jumper (see table) and wire seating.

No cool / not cooling

Wait out compressor delay; set 2°F below and retest.
Verify Y call present and wire fully seated.
On HP, ensure O vs B isn’t reversed.

Heat pump heating vs cooling backwards

Swap reversing-valve assignment: move wire between O and B and reconfigure.

AUX heat not working

Confirm AUX exists and is enabled; not in staging delay.
Check W/W2 placement (AUX is usually W).

Fan issues

Fan too early / not expected → set Heat Type correctly (Electric vs Fossil).
Fan not running → verify G wire seated and jumper logic.
Consider compressor delay or Fan Duty Cycle timing.

System Protect / Safety Delay

Short-cycle protection (5 min). Frequent triggers: move R to RC (cooling) and reconfig, or install isolation relay.

Advanced diagnostics

Manual wire checks

Strip ~1/4" straight; fully seat; light pressure on release tab when inserting.
Tug-test each suspect conductor.

Multimeter (ADC-T2000)

For C/Y/Y2/G/O-B: Red on RC, black on target terminal → expect 18–30 VAC.
For Z/W2/W: Red on RH, black on target terminal → 18–30 VAC.
0 V → missing power feed (R/jumper) or open circuit; re-strip/re-seat.

Bypass auto wire detection (T3000)

Menu → Settings → Installer → Continue → Reconfig → Yes
Select RH only / RC only / RH & RC
On wiring screen choose No → Bypass and set manually

Special messages

Power Resistor Required → install 1000 Ω, ½ W across zone valve terminals 1–2 (hydronic).
Isolation relay required → overcurrent on W/Y/G; isolate (e.g., Emerson 90-380) or call HVAC.

Need a hand?

We can assist with wiring verification, system type setup, and panel integrations.

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ADC-T3000 / ADC-T2000 — Heating & Cooling Troubleshooting Guide