Controls for 37MU(R,H)A & Crossover Applications
37MU(R,H)A & Crossover Applications
General Installation Notes:
- Indoor unit is NOT powered from outdoor unit.
- O/B Energized on Heating.
- Y2 Terminal at outdoor unit can be utilized instead of Y1 for faster ramp up rate; diagrams to follow.
- For FT5 applications – Recommend “HP-EFF” setting on Easy Select Board.
- Must use dual fuel thermostat for all furnace combinations. Simultaneous Heat Pump and Furnace operation not permitted.
- No wiring diagrams shown will operate a Furnace during Defrost.
- For Furnace applications – Indoor Fan will NOT shut off during Defrost unless a relay is added.
- Furnace applications require outdoor sensor or Wi-Fi weather data.
Product Compatibility:
| Air Handlers | Gas Furnaces C / B |
|---|---|
| FE5B | 59MN7C / 987M |
| FT5 | 59TN6C / 926S |
| FJ5 | 59CU5B / 986T |
| FG5 | 59TP6C / 926T |
| F55 | 59SP6B / 926S |
| FMA5X | 59SC6A / 916S |
| FMU(C)5X | 59SC2E / 912S |
| FMU(C)5Z | 59SU5 / 935S |
| FMA5L | 58TN0B / 880TB |
| Coils | 58CU0B / 830CB |
| CVAVA | 58TP0B / 821TB |
| CVAMA | 58SP0B / 820SB |
| CAAMP | 58SC0B / 800SB |
| CSAHP | 58SB0B / 912S |
| 58SU0B / 830SB | |
| Oil Furnaces Hi (M) / Lowboy (L) | |
| OVM / OVL | |
| OBM / OBL |
Note: Single Fan ODU height varies by capacity.
Outdoor units models include: 37MURA* 18, 24, 30, 36, 48, 60K and 37MUHA* 18, 24, 30, 36, 48K, 37MUHA 60K.
37MU(R,H)A & Crossover Application Thermostat Choices
Most 24-Volt thermostats will work for Crossover Applications. Refer to the Application/Installation instructions for specific details for the model installing.
It is strongly recommended that these systems are always wired as a Heat Pump, not Conventional.
NOTE: Dual Fuel Crossover Applications require the thermostat to sense outside temperature to operate correctly.
Thermostat Options:
- ecobee: No outside temperature sensor required, uses Wi-Fi weather data, stores up to 5 days.
- Cielo: No outside temperature sensor required, uses Wi-Fi weather data, stores up to 5 days.
- Nest: Hard wired outside temperature sensor must be installed.
- Honeywell: Hard wired outside temperature sensor must be installed.
- VIVE: Hard wired outside temperature sensor must be installed.
Attention: Thermostat must sense Outdoor temp for Dual Fuel Applications.
37MU(R,H)A – Applications Requiring Defrost or Error Signal from Outdoor Unit ODU
An R wire from the Indoor Unit to the Outdoor would be required only in applications where a Defrost (D-terminal ODU) or Error (L-terminal ODU) signal is needed.
Applications would include:
- Thermostats that accept a 24-Volt Error signal from outdoor unit (L-terminal).
- Applications that use a Defrost signal (D-terminal) to activate a relay to shut down the indoor fan during defrost.
- Applications that use a Defrost signal (D-terminal) to bring on the electric heat kit or other heat source; field supplied relay may be required.
Outdoor Unit MU(R,H)A Wiring:
Set S1-2 to ON at ODU for 24-Volt Connections.
Terminal connections:
- D
- L
- B
- Y2
- Y1
- W
- C
- R
Res. Indoor Coil Dissipation Board Overview
Main components:
- Dissipation Board
- Main Harness
- Leak Sensor
Dissipation Board Wiring (Example):
| PIN | COLOR | 1-Stage Label | 2-Stage Label |
|---|---|---|---|
| 1 | Red | to Furnace SEC1 | to Furnace SEC1 |
| 2 | Grn/Vio | to Furnace G | to Furnace G |
| 3 | White | to TSTAT W | to TSTAT W1 |
| 4 | Yel/Vio | to OD unit Y | to OD unit Y1 |
| 5 | Yellow | to Furnace Y | to Furnace Y1 |
| 6 | Green | to TSTAT G | to TSTAT G |
| 7 | White/Vio | to Furnace W | to Furnace W1 |
| 8 | Black | to Furnace C | to Furnace C |
See Installation Instructions For Specific Details.
Model Number: 350110-701 REV. C
Dissipation Board Overview
Sensor connection
Main harness connection
Flash Code Chart:
| Yellow (LED) | Mode | Status |
|---|---|---|
| Solid | Normal Operation | Normal Operation |
| Flashing 1 | Compressor Lockout | Normal Operation |
| Flashing 2 | Sensor Open | Normal Operation |
| Flashing 3 | Defrost Mode | Normal Operation |
| Flashing 4 | Defrost Mode | Normal Operation |
| Flashing 5 | Feed with All Light Sensor | Normal Operation |
| Flashing 6 | Feed with All Light Sensor | Normal Operation |
| Flashing 7 | Y1/Y2 to Compressor | Normal Operation |
| Flashing 8 | Y1/Y2 to Compressor | Normal Operation |
Dissipation Board Overview
Wire connections:
- Shipped with Indoor Coil.
- Designed to work with a Carrier or Bryant furnace.
- Make sure to review Installation Manual prior to connecting device.
Wiring Diagram:
Stat connections
Furnace transformer
Furnace control connections
37MU(R,H)A & 1-Stage Furnace - Dual Fuel Applications
Includes Carrier/Bryant 2-Stage Gas Furnaces utilizing Comfort Heat Technology® or Adaptive Mode.
When setting up the thermostat, make sure to disable furnace and heat pump running at the same time.
Thermostat Notes:
- 2 Stage Heat & 1 Stage Cool
- 1 Stage Heat Pump
- 1 Stage Gas Furnace
System Notes:
- Factory wires from Diss. Board to Furnace not shown.
- High Voltage wiring to equipment not shown.
- Indoor Fan ON during Defrost.
- Furnace will NOT operate during Defrost.
Wiring Diagram:
Thermostat Connections: W2, W1, O/B, Y2, Y1, G, C, Rc
Dissipation Board Connections: W-IN, Y-IN, B, G-IN, Y-Out
Single Stage Furnace Connections: R, C, G, Y1/Y2, W
Outdoor Unit MU(R,H)A Connections: B, Y2, Y1, W, C, R, D
Note: Y1 Terminal at ODU can be utilized instead of Y2 for slower ramp up rate.
Attention: Thermostat must have Outdoor temp sensor for Dual Fuel Applications.
Outdoor Unit Wiring: Set S1-2 to ON at ODU for 24-Volt Connections.
37MU(R,H)A & FT5 / FTG / F55 Fan Coils
Thermostat Notes:
- 2 Stage Heat & 1 Stage Cool
- 1 Stage Heat Pump
- 1 Stage Electric Heat
System Notes:
- Factory wires from Diss. Board to Fan Coil not shown.
- High Voltage wiring to equipment not shown.
- Indoor Fan ON during Defrost.
- Electric Heat ON during Defrost.
Wiring Diagram:
Thermostat Connections: W2, W1, O/B, Y2, Y1, G, C, Rc
Dissipation Board Connections: W-IN, Y-IN, W-OUT, Y1
Fan Coil Connections: R, C, G, Y1/Y2, W/W1, W2
Outdoor Unit MU(R,H)A Connections: B, Y1, Y2, W, C, R, D
Note: Y1 Terminal at ODU can be utilized instead of Y2 for slower ramp up rate.
Recommendation: Recommend “HP-EFF” setting on Easy Select Board during initial set up.
Outdoor Unit Wiring: Set S1-2 to ON at ODU for 24-Volt Connections.
37MU(R,H)A & FT5 / FTG / F55 Fan Coils (7-wire configuration)
Thermostat Notes:
- 3 Stage Heat & 1 Stage Cool
- 1 Stage Heat Pump
- 2 Stage Electric Heat
System Notes:
- Factory wires from Diss. Board to Fan Coil not shown.
- High Voltage wiring to equipment not shown.
- Indoor Fan ON during Defrost.
- Electric Heat ON during Defrost.
Wiring Diagram:
Thermostat Connections: W2, W1, O/B, Y2, Y1, G, C, Rc
Dissipation Board Connections: W-IN, Y-IN, W-OUT, Y1
Fan Coil Connections: R, C, G, Y1/Y2, W/W1, W2
Outdoor Unit MU(R,H)A Connections: B, Y1, Y2, W, C, R, D
Note: Y1 Terminal at ODU can be utilized instead of Y2 for slower ramp up rate.
Recommendation: Recommend “HP-EFF” setting on Easy Select Board during initial set up.
Outdoor Unit Wiring: Set S1-2 to ON at ODU for 24-Volt Connections.
37MU(R,H)A & F55 Fan Coils (7-wire configuration)
Thermostat Notes:
- 3 Stage Heat & 1 Stage Cool
- 1 Stage Heat Pump
- 2 Stage Electric Heat
System Notes:
- Factory wires from Diss. Board to Fan Coil not shown.
- High Voltage wiring to equipment not shown.
- Indoor Fan ON during Defrost.
- Electric Heat ON during Defrost.
Wiring Diagram:
Thermostat Connections: W2, W1, O/B, Y2, Y1, G, C, Rc
Dissipation Board Connections: W-IN, Y-IN, W-OUT, Y1
Fan Coil Connections: R, C, G, Y1/Y2, W/W1, W2
Outdoor Unit MU(R,H)A Connections: B, Y1, Y2, W, C, R, D
Note: Y1 Terminal at ODU can be utilized instead of Y2 for slower ramp up rate.
Recommendation: Recommend “HP-EFF” setting on Easy Select Board during initial set up.
Outdoor Unit Wiring: Set S1-2 to ON at ODU for 24-Volt Connections.
37MU(R,H)A & FJ5 Fan Coils
Thermostat Notes:
- 2 Stage Heat & 1 Stage Cool
- 1 Stage Heat Pump
- 1 Stage Electric Heat
System Notes:
- Factory wires from Diss. Board to Fan Coil not shown.
- High Voltage wiring to equipment not shown.
- Indoor Fan ON during Defrost.
- Electric Heat ON during Defrost.
Wiring Diagram:
Thermostat Connections: W1, O/B, Y1, Y2, G, C, Rc
Dissipation Board Connections: W-OUT, W-IN, Y-IN, Y-OUT
Fan Coil Connections: R, C, G, E, W2, W3
Outdoor Unit MU(R,H)A Connections: B, Y2, Y1, W, C, R, D
Note: Y1 Terminal at ODU can be utilized instead of Y2 for slower ramp up rate.
Outdoor Unit Wiring: Set S1-2 to ON at ODU for 24-Volt Connections.
37MU(R,H)A & Multi-family Indoor Units FMA5L(X) / FMC5X(Z) / FMU5X(Z) Fan Coils
Notes:
- Dissipation board built-in to main PCB in fan coil.
- High Voltage wiring to equipment not shown.
- Indoor Fan ON during Defrost.
- Electric Heat ON during Defrost.
Wiring Diagram:
Thermostat Connections: W1, O/B, Y2, Y1, G, C, Rc
Fan Coil Connections: R, C, G, Y1, O/B, W, Y, O/B, C
Outdoor Unit MU(R,H)A Connections: B, Y2, Y1, W, C, R, D
Note: Y1 Terminal at ODU can be utilized instead of Y2 for slower ramp up rate.
Outdoor Unit Wiring: Set S1-2 to ON at ODU for 24-Volt Connections.
Ductless systems and Residential systems can talk without wires
Cielo's Linked feature can talk through the Cielo App. Decisions can change the other based on outdoor temp or state of other system and more.
As you work your way through the decision-making process, it takes a few screens, but in the end a "Link conditions" screen shows you the rule. Think of it as "If this, then that". The rule can be toggled ON and OFF.
Thermostat Options:
- Cielo Smart Thermostat (24-Volt)
- Cielo Breez Max (DLS)
Cielo App Features:
- Linked feature for multi-zone mini-split control.
- Automatically switch modes or turn off your multi-zone indoor units in case of mode conflict.
- User account management, language settings, help, and about sections.
