9 Best Programmable Heat Only Thermostats (November 2026)

The best programmable heat only thermostats include the LUX PSD010B Non-Programmable 2-Wire Heat-Only Thermostat for simple 2-wire heat-only systems, the Suuwer Non-Programmable Thermostats for Home 1 Heat/1 for readable single-stage controls, and the Google Nest Thermostat for app-based scheduling.

On this page (12 sections)

1. Which programmable thermostat is best for heat only systems?
2. Google Nest Thermostat: best for app-based scheduling
3. Suuwer S705: best for weekday and weekend schedules
4. Honeywell Home X2P: best for a simple 5-2 schedule
5. LUX PSD010B: best for simple 2-wire heat-only systems
6. Riseem: best for broad single-stage heat-only applications
7. Honeywell Home RLV3120: best for line-voltage electric heat
8. Garystat: best for heat pump systems
9. White-Rodgers 70 Series Classic: best for 24-volt or millivolt heat
10. How do you choose a programmable heat-only thermostat?
11. Is a programmable thermostat worth it for heat-only systems?
12. Best programmable thermostat for heat only: final picks

The best programmable thermostat for heat only systems is the Google Nest Thermostat when your wiring supports it. It suits homes where you leave during the day and want the temperature to ease back before you return.

The Suuwer S705 and Honeywell Home X2P suit people who prefer traditional wall controls over an app.

A programmable model suits a steady routine with clear sleep, work and evening periods. It lets you set a cooler level overnight and a warmer level for waking hours.

That structure helps most when your days follow a pattern you can repeat.

The main decision is matching the thermostat to your system voltage, wire terminals and heating stages. A heat only label does not mean every heat only thermostat will connect safely to your equipment.

Low voltage furnace controls and line voltage baseboard controls need different products.

Check the existing thermostat and wiring before you choose a replacement. Note the terminals used and whether the system is a furnace, boiler, fireplace, radiant setup or electric baseboard.

That brief check helps you avoid a unit that lacks the right connection type.

If you only need manual control, compare our guide to the best non programmable heat only thermostat. It covers simpler units with one setpoint and fewer settings to manage.

That route suits irregular schedules where a fixed program would cause more adjustments than it saves.

If you are replacing a simple two-wire setup, our guide to the best 2 wire heat only programmable thermostat focuses on that wiring pattern. It shows which options match a basic heat only circuit and which need extra power.

Choose scheduling when your routine is predictable and you will use the set periods. Choose manual control when plans change often or you prefer to adjust from the wall.

Compatibility comes first because it decides whether the thermostat can run your heating system properly.

Our picks at a glance

1. 1
   Best for simple 2-wire heat-only systems

   LUX PSD010B Non-Programmable 2-Wire Heat-Only Thermostat

   9.7/10 our score

   See it on Amazon
2. 2
   Best for readable single-stage controls

   Suuwer Non-Programmable Thermostats for Home 1 Heat/1

   9.7/10 our score

   See it on Amazon
3. 3
   Best for app-based scheduling

   Google Nest Thermostat

   9.7/10 our score

   See it on Amazon

4. 4

   Riseem NonProgrammable Thermostat for Home

   Best for broad single-stage wiring
   Check it
5. 5

   Garystat Non-Programmable Heat Pump Thermostat for House

   Best for heat pump compatibility checks
   Check it
6. 6

   Honeywell Home Digital Non-Programmable Thermostat for Electric

   Best for line-voltage electric heat
   Check it
7. 7

   Suuwer 5-1-1 Day Programmable Thermostats for Home

   Best for weekday and weekend schedules
   Check it
8. 8

   White-Rodgers 70 Series Classic

   Best for 24-volt or millivolt heat
   Check it
9. 9

   Honeywell Home X2P Programmable Thermostat

   Best for simple 5-2 programming
   Check it

Which programmable thermostat is best for heat only systems?

The Google Nest Thermostat is the best fit for app-based scheduling, while the Suuwer S705 and Honeywell Home X2P suit familiar wall-mounted controls. That split helps you decide based on how you want to change the temperature day to day.

An app suits remote changes, while wall controls suit quick manual tweaks.

A thermostat made for heat-only use may still be non-programmable, so separate schedule needs from compatibility needs. Heat only describes what the system heats, while programmable describes how the setpoint changes over time.

Some readers need both, and some need only one of those traits.

We compared system types, wiring notes, power options, scheduling features and daily controls. That approach shows where a model fits a furnace, boiler, fireplace or baseboard setup.

It also shows whether power comes from batteries, 24VAC supply or a C-wire.

For work hours, a schedule can lower the setpoint while the home is empty. For sleep, it can keep the room cooler without a late night adjustment.

For mornings, it can warm the space before the first occupied period. Those gains depend on a routine that stays broadly consistent.

For daily use, display size and button layout matter more than extra features. A backlit screen helps in dark hallways, and simple controls help guests or family members make a change.

Large controls also suit people who do not want to learn a phone app for a basic task.

Power is another dividing line. Battery operation can reduce wiring needs, but batteries still need replacing.

A C-wire can support some smart models, yet older heat only systems may not have one.

Trade-offs appear in every group here. Programmable models add settings to learn, while non-programmable models keep control simple.

Smart models add remote access, while basic models avoid dependence on Wi-Fi.

Use compatibility as the first filter and schedule type as the second. That order prevents a strong scheduling feature from hiding a wiring problem.

Once compatibility is clear, choose the control style you are most likely to use each day.

Google Nest Thermostat: best for app-based scheduling

3

Google Nest Thermostat: Best for app-based scheduling

9.7/10Our score

• Programmable Wi-Fi control
• Google Home app scheduling
• Away temperature adjustment
• Works with compatible smart home platforms

Google Nest is the strongest choice here for remote scheduling and app control. Heat-only compatibility needs extra attention because Google notes that some heat-only systems need a C-wire or another compatible power accessory.

See it on Amazon

Pros

• Remote control from phones and tablets
• Flexible app scheduling
• Away temperature adjustment

Cons

• Heat-only systems may need a C-wire
• Requires Wi-Fi for remote features

Google Nest is the most capable scheduling option in this group. You can create an energy-focused schedule in the Google Home app, adjust the temperature remotely and allow the thermostat to lower the setting when you leave.

Heat-only buyers need to pay close attention to power. Google says some heating-only systems need a C-wire or another compatible power accessory, even though the thermostat is designed to work without a C-wire in many homes.

The Wi-Fi connection supports remote control from a phone, laptop or tablet. Alerts and maintenance reminders can also help you notice potential system issues, but they do not replace a professional HVAC diagnosis.

The thermostat includes 2 AAA batteries, mounting screws, a steel plate and documentation. It has a snow finish, a 3.31 in wide by 3.31 in high body and a 1.07 in depth.

Choose it when remote control and automatic schedules matter. Check Google's Nest compatibility information before buying, especially for a dedicated heat-only system.

Suuwer S705: best for weekday and weekend schedules

7

Suuwer 5-1-1 Day Programmable Thermostats for Home: Best for weekday and weekend schedules

9.1/10Our score

• 5-1-1 scheduling
• 4 program periods per day
• 1 heat/1 cool control
• Battery powered

The Suuwer S705 is the best traditional schedule option for buyers who want different weekday, Saturday and Sunday settings. It supports some heat-only furnace, boiler radiant and gas fireplace applications, but heat-only systems require careful wiring checks.

See it on Amazon

Pros

• 4 periods per day
• 5-1-1 schedule
• Filter and battery reminders

Cons

• Not for line-voltage baseboards
• Heat-only systems may require a C-wire

The Suuwer S705 provides a 5-1-1 schedule with 4 periods per day: wake, leave, return and sleep. That gives you separate weekday, Saturday and Sunday routines without requiring an app or Wi-Fi connection.

It supports 1 heat and 1 cool conventional systems, including some gas, oil or electric furnaces, boiler radiant systems and 24-volt gas fireplaces. It does not support 120 to 240V electric baseboards, multi-stage systems or several listed heat pump configurations.

The thermostat uses 24VAC or 2 AAA batteries. Suuwer says a C-wire is not required on most single-stage systems, but heat-only systems may require one, so compare the current terminal layout before installation.

For more low-voltage choices, see low-voltage heat-only thermostats.

A blue-backlit 4.5-inch display keeps the schedule and temperature easy to read. The unit also includes separate heat and cool swing settings, a low-battery indicator, filter reminders and selectable 5-minute compressor delay protection.

Choose it if you want a classic programmable heat-only thermostat with separate weekend control. Skip it when your system uses line voltage or has more than one heating stage.

Honeywell Home X2P: best for a simple 5-2 schedule

9

Honeywell Home X2P Programmable Thermostat: Best for simple 5-2 programming

8.7/10Our score

• 5-2 day scheduling
• Backlit display
• Filter reminders
• Battery powered

Honeywell Home X2P gives you a familiar 5-2 schedule for single-stage forced air, hot water heat and some single-stage heat pumps. It is not compatible with 120 to 240V electric baseboard heat or multi-stage systems.

See it on Amazon

Pros

• 5-2 scheduling
• Large screen and clear font
• No C-wire required

Cons

• Not for electric baseboards
• 2 AA batteries are not included

The Honeywell Home X2P gives you a 5-2 schedule, so weekdays share one routine and Saturday and Sunday share another. It also offers a non-programmable option if you decide that fixed manual control is easier.

The X2P is designed for 1 heat/1 cool systems, including single-stage forced air using gas, oil or electric heat, hot water heat, 750 mV systems and single-stage heat pumps. It does not work with 120 to 240V electric baseboard heat or multi-stage systems.

Its large screen, backlit display and custom display settings help with daily adjustments. A filter-change reminder can also support routine maintenance, although it does not measure filter condition.

The thermostat is battery powered with 2 AA batteries, and those batteries are not included. Honeywell Home also includes an easy-install UWP wall plate, which can make a replacement more orderly when the existing system matches the required connections.

Choose it if you want a basic 5-2 schedule without Wi-Fi. Check the system voltage and heating stages before choosing it for a dedicated heat-only replacement.

LUX PSD010B: best for simple 2-wire heat-only systems

1

LUX PSD010B Non-Programmable 2-Wire Heat-Only Thermostat: Best for simple 2-wire heat-only systems

9.7/10Our score

• 2-wire heat-only design
• Large illuminated LCD
• Battery powered
• Designed for fireplaces, stoves and in-floor radiant heat

The LUX is a straightforward heat-only replacement for buyers who value simple control over scheduling. Its 2-wire design suits some fireplaces, stoves and in-floor radiant systems.

See it on Amazon

Pros

• 2-wire heat-only design
• Large illuminated display
• Battery powered

Cons

• Non-programmable
• System compatibility still needs checking

The LUX PSD010B is not programmable, but it is a strong fit when your priority is simple control for a 2-wire heat-only system. It is designed for applications such as fireplaces, stoves and in-floor radiant heating.

Its large illuminated LCD makes the set temperature easier to read. Button controls keep daily adjustments direct, and battery power avoids depending on a C-wire for the thermostat itself.

The unit is 3.3 in wide, 5 in high and 1.1 in deep. It is wall mounted, made of plastic and uses 2 included AA batteries.

This model makes sense when the existing thermostat has a compatible 2-wire heat-only setup. It does not solve a need for weekday or weekend temperature changes, so choose a programmable model when schedule control is the reason for replacing the thermostat.

For another heat-only option from the same brand category, compare our guide to the best heat only thermostat.

Riseem: best for broad single-stage heat-only applications

4

Riseem NonProgrammable Thermostat for Home: Best for broad single-stage wiring

9.5/10Our score

• 1 heat/1 cool conventional control
• White backlight LCD
• 2 to 5 wire base
• 24VAC or 2 AA battery power

Riseem gives heat-only buyers a digital option for several single-stage applications, including furnace, boiler radiant and 24-volt gas fireplace systems. It remains non-programmable, so choose it for basic control rather than scheduled temperature changes.

See it on Amazon

Pros

• Heat-only applications are clearly stated
• White backlight display
• 2 to 5 wire base

Cons

• Heat-only and cool-only systems require a C-wire
• Not compatible with line-voltage electric baseboard heat

Riseem's S3001-White is a non-programmable thermostat for single-stage systems with up to 1 heat and 1 cool. Its stated heat-only applications include gas or oil furnace heat, boiler radiant heat, furnace forced air and 24-volt gas fireplaces.

The thermostat has a white-backlight LCD and large terminal blocks. It supports 2 to 5 wires at the base and can use 24VAC power or 2 AA batteries, although the product information notes that heat-only and cool-only systems require a C-wire.

Separate heating and cooling swing settings let you adjust the cycle behavior. Riseem also gives a room display range of 41 F to 95 F and a temperature control range of 44 F to 90 F.

The wall-mounted body is 5.43 in wide, 3.86 in high and 1.06 in deep. It includes the thermostat, 2 screws and anchors, an operating manual and a cable label.

Choose Riseem when you want a clear digital replacement for a compatible single-stage heat-only system. Do not use it for electric baseboard heat, heat pumps, mini-splits or other systems listed as incompatible.

Honeywell Home RLV3120: best for line-voltage electric heat

6

Honeywell Home Digital Non-Programmable Thermostat for Electric: Best for line-voltage electric heat

9.4/10Our score

• 2-wire line-voltage connection
• Electric baseboard and convector compatibility
• TRIAC silent switching
• 2,000W maximum load at 240V

Honeywell Home RLV3120 is the right direction when your heat-only system uses line voltage for electric baseboards or convectors. It is non-programmable, and it cannot be used with a fan-forced convector.

See it on Amazon

Pros

• Made for line-voltage electric heat
• Silent TRIAC switching
• Controls smaller baseboard loads

Cons

• Not programmable
• Not for low-voltage heat-only systems

The Honeywell Home RLV3120 is the right type of thermostat for electric baseboards and convectors using 120V or 240V line voltage. This is a different category from low-voltage furnace and boiler thermostats, so do not treat a 2-wire connection as proof that the models are interchangeable.

It uses a 2-wire non-polarized connection and TRIAC switching. Honeywell Home states a maximum load of 2,000W at 240V, with a 200W minimum load at 240V.

The digital display shows a heating power indicator, and push-button controls adjust the setpoint. Silent switching avoids the clicking associated with some mechanical thermostats.

The unit is 3.2 in wide, 4.8 in high and 1.1 in deep. It includes the RLV3120 thermostat, 2 mounting screws and 2 solderless connectors.

Choose it only when your heat-only system is line-voltage electric heat. It is not programmable and cannot be used with a fan-forced convector.

Garystat: best for heat pump systems

5

Garystat Non-Programmable Heat Pump Thermostat for House: Best for heat pump compatibility checks

9.4/10Our score

• 2 heat/1 cool control
• Temperature and humidity monitor
• Large green LCD
• 3-minute compressor delay protection

Garystat is for a different wiring problem than a basic heat-only replacement because it supports heat pump and 2 heat/1 cool systems. Its temperature and humidity monitor may help you track room conditions, but it does not provide programmable scheduling.

See it on Amazon

Pros

• Supports heat pump systems
• Temperature and humidity monitor
• Large green display

Cons

• Not programmable
• Not compatible with 120 to 240V line-voltage systems

Garystat is included because some readers use the phrase heat-only thermostat when they actually have a heat pump system. This model supports heat pump and conventional forced-air systems with 2 heating stages and 1 cooling stage.

Its large green LCD shows temperature information, and the thermostat includes a temperature sensor. Garystat also describes a humidity and temperature monitor, 3-minute compressor delay protection and a low-battery reminder.

The thermostat can use 24VAC power or 2 AAA batteries. Its listed terminal connections include O, B, E/W, W2, R, G, Y and C, which shows why a heat pump wiring check is essential before installation.

This is a non-programmable model, so it does not meet the scheduling goal by itself. It is useful when compatibility with a heat pump matters more than weekday and weekend programming.

Choose it for compatible heat pump or conventional systems. Do not use it with 120 to 240V electric baseboard heat or RV thermostat systems.

White-Rodgers 70 Series Classic: best for 24-volt or millivolt heat

8

White-Rodgers 70 Series Classic: Best for 24-volt or millivolt heat

9.0/10Our score

• Single-stage heat-only compatibility
• Backlit digital display
• Plus or minus 1 F control
• 24-volt and millivolt system support

White-Rodgers 1E78-140 suits buyers replacing a basic 24-volt or millivolt heat-only thermostat. Its vertical profile and backlit display keep the focus on clear manual temperature control.

See it on Amazon

Pros

• Works with 24-volt and millivolt systems
• Backlit digital display
• Large vertical profile

Cons

• Not programmable
• Not for electric baseboard heat

The White-Rodgers 1E78-140 is a non-programmable thermostat for most single-stage heat-only systems using 24-volt or millivolt power. It provides manual control rather than a weekday schedule.

A backlit digital display makes the setpoint easier to read. White-Rodgers also gives plus or minus 1 F control, which suits buyers who want simple temperature adjustments without app features.

The vertical body measures 5-5/16 in high, 3-3/16 in wide and 1-1/8 in deep. It uses 3 included AAA batteries and mounts on the wall.

This thermostat is a practical choice when the existing system is a compatible low-voltage or millivolt heat-only setup. It is not for electric baseboard heat, so confirm the system type before connecting it.

Choose this model when the replacement goal is clear manual control and a vertical profile. Choose a programmable model if reducing the temperature on a daily routine is the main reason for upgrading.

How do you choose a programmable heat-only thermostat?

Choose by system voltage first, wiring second and schedule type third. A 5-2 or 5-1-1 schedule cannot compensate for a thermostat that is incompatible with your heating equipment.

Is your heat-only system low voltage or line voltage?

Low-voltage furnaces, boilers, millivolt systems and 24-volt fireplaces use different controls from electric baseboards. Low voltage systems usually carry control signals to equipment that does the heating elsewhere in the home.

Electric baseboards draw line voltage at the heater itself, so the thermostat and wiring must be rated for that load.

The Honeywell Home RLV3120 is specifically for 120V or 240V electric heat, while White-Rodgers and several other picks are for low-voltage or millivolt applications. That difference is not a minor detail.

A low voltage thermostat cannot safely switch a line voltage baseboard circuit, and a line voltage model will not suit a furnace control circuit.

If you see thick wires, high-voltage labels or an electric baseboard heater, stop and confirm the voltage before removing the old thermostat. Thick wires often signal a higher load, but they are not proof on their own.

Labels on the old thermostat, heater or panel can give a clearer answer.

When the system type is unclear, use an HVAC professional. A professional can confirm voltage, stages and wiring before a new unit is fitted.

That check is easier to accept than undoing an incorrect install.

Millivolt systems need the same care. They power some gas fireplaces and stoves through a small voltage signal rather than a standard furnace control circuit.

A thermostat that claims broad heat only support may still need a specific millivolt mode or connection. Read the compatibility notes for your exact equipment type.

Baseboard systems need a load check as well. The thermostat must match the total wattage and amperage of the heaters it will control.

A unit that fits the voltage may still be wrong if the load exceeds its limit. Check both voltage and load before you narrow the shortlist.

Keep the old thermostat in place until you have the replacement details ready. Photograph the wiring and note each terminal label while the unit is still connected.

That record helps you compare the old setup with the new model without guessing from memory later.

Choose by voltage first, then by wire count, then by schedule. Once voltage and system type are confirmed, the remaining choices become much easier to judge.

How many wires and terminals are present?

Count the wires and record the terminal labels before disconnecting anything. Two wires may indicate a simple heat-only circuit, but the voltage and equipment type still matter.

The LUX PSD010B is designed around 2-wire heat-only systems. Suuwer and Riseem describe 2 to 5 wire compatibility for certain conventional systems, while Google notes that some heat-only Nest installations need a C-wire or compatible power accessory.

Which schedule fits your routine?

Choose 5-2 when weekdays follow one pattern and both weekend days are similar. Choose 5-1-1 when Saturday and Sunday need separate settings.

Choose app scheduling when you want remote control or automatic away adjustments. Choose a non-programmable thermostat when you prefer one manual setpoint and want fewer settings to manage.

What should you check before installation?

Turn off power according to the thermostat and heating system instructions. Photograph the existing wiring, label each wire by terminal and compare the old system with the new thermostat's compatibility information.

Do not rely on the number of wires alone. Heat pumps, line-voltage baseboards, multi-stage equipment and heat-only systems can require different thermostat designs.

Is a programmable thermostat worth it for heat-only systems?

A programmable thermostat is useful when your home has predictable empty, sleep and occupied periods. Predictable patterns let you set cooler levels for hours when no one needs full warmth.

They also let you time a warmer period for just before people get up or return.

Lowering the setpoint during empty hours can reduce unnecessary heating, but the benefit depends on your schedule and system response. A home that stays occupied all day may gain little from a fixed program.

A home with steady work hours and a regular sleep pattern may gain more.

Heating systems respond at different speeds. Radiant floors can hold warmth and release it slowly after the setpoint changes.

Forced air systems can respond faster, which makes timed changes easier to notice. Your equipment type shapes how useful a schedule will feel in daily use.

The Google Nest Thermostat offers the most flexible control here through Wi-Fi and the Google Home app. It suits people who want to change the temperature from another room or from outside the home.

Remote access can help when plans change and the usual return time shifts.

The Suuwer S705 and Honeywell Home X2P suit buyers who want schedules from the wall without relying on an app. That approach keeps control local and avoids dependence on a phone or network connection.

It also suits households where several people use the same wall unit each day.

A non-programmable model may be better when the home is occupied on an irregular schedule or when compatibility is difficult. Irregular shifts, care duties or guests can make fixed periods feel restrictive.

In those homes, a clear manual setpoint may lead to fewer day to day adjustments.

In that case, our guide to the best Honeywell heat only thermostat can help narrow the manual-control options. It focuses on simple control and system fit rather than daily programming.

That is a better starting point when ease of use matters more than automation.

Setup matters for long term value. A schedule that is too complex will not be maintained, and a schedule that is too simple may not match your routine.

Keep the periods few and clear so the program stays useful through seasonal changes.

Choose a programmable model when your routine repeats and you want the home to adjust itself. Choose a non-programmable model when your routine changes or you prefer direct control.

The right answer depends less on features and more on how your household actually uses the space each day.

Best programmable thermostat for heat only: final picks

The Google Nest Thermostat is the best choice for app-based scheduling when your heat-only wiring and power setup are compatible. It suits buyers who want remote control, away adjustments and a schedule managed from a phone.

Check compatibility first because some heat-only systems need a C-wire or a compatible power accessory.

Pick the Suuwer S705 for separate weekday, Saturday and Sunday schedules. Its 5-1-1 pattern helps when Saturday and Sunday do not share the same routine.

It also suits buyers who want wall controls with a backlit display and no app requirement.

Pick the Honeywell Home X2P for a simpler 5-2 routine. One weekday schedule and one weekend schedule cover many households without extra settings.

Its large screen and backlit display make daily changes plain and quick.

Choose based on routine before you choose based on brand. A 5-1-1 schedule fits homes with two different weekend days.

A 5-2 schedule fits homes where Saturday and Sunday follow the same pattern. App scheduling fits homes where remote changes matter more than wall-based simplicity.

For a basic replacement, choose the LUX PSD010B for compatible 2-wire heat-only systems. It suits fireplaces, stoves and in-floor radiant setups where simple manual control is enough.

It does not add a schedule, so it fits a steady setpoint rather than a timed routine.

For electric baseboards, choose the Honeywell Home RLV3120 because line-voltage compatibility matters more than programmable features. It is made for 120V or 240V electric heat and uses silent TRIAC switching.

Low voltage models should not be treated as substitutes for that setup.

Other picks fill narrower roles. Riseem suits several single-stage heat-only applications with a clear digital display.

White-Rodgers suits 24-volt or millivolt heat-only systems with simple manual control. Garystat suits heat pump systems rather than a basic heat-only replacement.

Read the wiring notes for each shortlisted model before you order. Count the wires, note the terminal labels and confirm the voltage and heating stages.

That short check keeps the final choice aligned with your actual system. Match schedule type to your routine and match the thermostat to your system.

Our top 3 picks at a glance

1. 1
   Best for simple 2-wire heat-only systems

   LUX PSD010B Non-Programmable 2-Wire Heat-Only Thermostat

   9.7/10 our score

   See it on Amazon
2. 2
   Best for readable single-stage controls

   Suuwer Non-Programmable Thermostats for Home 1 Heat/1

   9.7/10 our score

   See it on Amazon
3. 3
   Best for app-based scheduling

   Google Nest Thermostat

   9.7/10 our score

   See it on Amazon

Frequently asked questions

What is the best programmable thermostat for heat only?

The Google Nest Thermostat is the strongest programmable option here when your heat-only system is compatible and has the required power setup. The Suuwer S705 and Honeywell Home X2P offer traditional schedules, but both need system and wiring checks before installation.

For a simple heat-only replacement without scheduling, choose a non-programmable model instead.

Can you use a programmable thermostat on a heat-only system?

Yes, but the thermostat must match the heating system and wiring. Low-voltage furnace, boiler and millivolt systems use different connections from 120 to 240V electric baseboard heat.

Check the existing terminals, voltage and compatibility guide before removing the old thermostat.

Turn off power at the correct breaker when required.

Do heat-only thermostats need a C-wire?

Some do and some do not. Google notes that certain heat-only systems need a C-wire or compatible power accessory, while other battery-powered thermostats can work without one in specific systems.

The number of wires alone does not confirm compatibility.

Match the system type, voltage and terminal labels.

What is the difference between 5-1-1 and 5-2 scheduling?

A 5-1-1 thermostat uses one schedule for Monday through Friday, one for Saturday and one for Sunday. A 5-2 thermostat uses one weekday schedule and one weekend schedule.

Choose 5-1-1 if Saturday and Sunday differ.

Choose 5-2 if both weekend days follow the same routine.

Can a heat-only thermostat control electric baseboard heat?

Only a thermostat made for line-voltage electric heat should control electric baseboards. The Honeywell Home RLV3120 is designed for 120V or 240V electric baseboards and convectors, while low-voltage heat-only thermostats are not interchangeable with that setup.

Check the voltage before connecting any replacement.