Do you heat your home with hydronic baseboard heaters? If so, you’ll need a reliable thermostats for your hydronic baseboard heating system.

A good thermostat will maximize energy efficiency and allow you to preset temperatures weeks in advance.

Don’t know where to get one of these?

We’re here to help. We’ve selected and reviewed the five best hydronic baseboard heater thermostats currently on the market. We’ve also shared the criteria using which we picked those five models.

Read on to find out more. 

In a Rush? Here are our top Picks

Our Criteria in Selecting the Best Thermostats

We selected all thermostats based on the following criteria:

• One-year warranty: All models that you see below come with a 1-year warranty. This should assure you that they would work as advertised and the money you’re going to spend on them won’t end up going to waste.

• Accurate sensor: Thermostats with an accurate temperature sensor let you decide the heater’s exact output. Otherwise, if the sensor is inaccurate, you’d either get too much heat (energy wastage) or too low heat (poor heating performance).

• Programmable schedule: Thermostats equipped with this feature let you set their heating schedule days (or even weeks) in advance. This saves you from the nuisance of having to adjust the thermostat every day.

Top 5 Best Hydronic Baseboard Heater Thermostats

Honeywell Flexible Programmable Thermostat

• Type: Programmable
• Power source: Battery
• Works with: Low voltage heaters
• Interface: Buttons

Tired of using thermostats that require constant programming? Looking for one that could learn your heating routine and adjust its temperature accordingly?

That’s precisely what the Honeywell Thermostat does. It monitors its run times for the first few days before adjusting the temperature automatically to meet your heating requirements.

Baseboard hydronic heaters need frequent air filter replacement or their performance nosedives, an unwanted scenario that this thermostat prevents by sending change reminders for filter replacement on its extra-large backlit display.

There’s nothing more frustrating than returning home and finding the house cold because the thermostat’s batteries died in your absence. You don’t have to worry about this problem with this model because it also sends low battery signals to help you change its batteries in time.

You don’t have to page through menus to get the information you need from this thermostat. Every piece of information crucial for its users – i.e., current room temperature, temperature setpoint, current mode, heat on/off status, etc. – is right there on its main screen.

However, not everything about this product is excellent. Its room temperature gauge stops working when you turn off the thermostat, which means it will display the same temperature it measured when the thermostat was still running unless you turn the unit back on.

Things We Like   

• Four modes (sleep, wake, leave, return)
• Day to day programmable schedule
• Change reminders for air filter replacement

Things We Don’t Like      

• Inaccurate room temperature gauge

How It Compares With Our Criteria

1. Warranty: 1-year
2. Accurate Sensor: Yes
3. Programmable Schedule: Yes

Ecobee 3 Lite Smart Thermostat

• Type: Smart
• Power source: C-wire
• Works with: Line voltage heaters
• Interface: Touch

Multiple features distinguish the Ecobee 3 lite from our top pick.

Most obvious is its smart functionality. Here’s a thermostat you can control from anywhere in the world with the Ecobee app or anywhere at home with leading smart home systems (Alexa, Google Assistant, etc.). This means you can program it without leaving your couch.

Then comes its energy efficiency.

On its own, this Energy Star® certified thermostat can bring down your annual heating (and cooling) costs by up to 23%. When paired with the SmartSensor (sold separately), which monitors your home’s hot and cold spots to deliver comfort accordingly, its energy consumption will decrease even further.

Next is its feature-rich display.

Its home screen displays the current temperature inside your home, current system mode (Off, Heat, Cool), and the current humidity level. Along the bottom are icons using which you can change temperature, adjust settings, set schedules, view a 5-day forecast, and more. 

It has several upgrades over 2017’s Ecobee 4 too.

The Ecobee 3 lite delivers faster performance with fewer lags. It also has a better-quality speaker with louder max volume, more robust materials for its casing and display, and a fully redesigned remote sensor. However, the Ecobee 4 does have a built-in Alexa Voice assistant that the Ecobee 3 lite lacks.

So why didn’t we pick this model as our top pick?

Some of its users have complained about the support quality from the manufacturer. We sympathize with them because we are aware that Ecobee’s history of service reliability is poor. Had it not been for this glaring problem, the Ecobee 3 lite would have been our top pick.

Things We Like   

• User-friendly touch interface
• Gives a 5-day weather forecast
• Energy Star® certified

Things We Don’t Like      

• Poor after-sale service
• Pricey

How It Compares With Our Criteria

1. Warranty: 3-year (limited)
2. Accurate Sensor: Yes
3. Programmable Schedule: Yes

Honeywell Home CT410B Thermostat

• Type: Manual
• Power source: Electric
• Works with: Line voltage heaters
• Interface: Dial

The Honeywell Home CT410B is the only manual thermostat in this review. And for good reasons too.

It is one of the very few models that are approved by UL and CSA for their safety. Perhaps because of its extra-thick wires that can handle more load (5,280 watts) than any other thermostat you see in here.

You can easily install this thermostat. Just gather the tools mentioned in its installation instructions, follow the guidelines to the letter, and you’d be able to get it up and running within half an hour, provided you have prior experience of installing electrical equipment.

Its bi-metal temperature sensor is highly accurate and lets you adjust the heater’s output with ease. And the best thing about the sensor is that it doesn’t transmit the captured heat to the thermostat’s body.

Yet another notable feature of this model is its price. You can get ten of these for the price of one Ecobee 3 lite, one of the most expensive models we reviewed. This makes this thermostat a must-have if you’re planning on buying multiple thermostats for multiple rooms.

However, since it’s a manual thermostat, you can’t expect it to offer many bells and whistles. And it is not super legible in low-light conditions. Also, since it’s a line-voltage thermostat, don’t count on it to replace your existing 12/24V model.

Things We Like   

• Straightforward operation
• Hassle-free installation
• Can handle 5,280 watts of load

Things We Don’t Like      

• Doesn’t offer any bells and whistles

How It Compares With Our Criteria

1. Warranty: 1-year
2. Accurate Sensor: Yes
3. Programmable Schedule: No

Mysa Smart Thermostat

• Type: Smart
• Power source: Electric
• Works with: Low voltage heaters
• Interface: Touch

Most smart thermostats you see on the market cannot control high/line voltage equipment. That means you cannot make them work with 120/240V electric hydronic baseboard heaters. The Mysa Smart Thermostat, fortunately, doesn’t pose this restriction.

This thermostat consists of two parts – a power board (which mounts to the wall) and the faceplate (that houses the controller board). Both are connected via a wire and anyone moderately experienced in electrical work can install this thermostat.

What sets this unit apart from its fellow smart thermostats is the user-friendly Mysa app. It lets you view the current temperature, adjust the temperature, create zones, and set schedules. It also allows you to control display brightness, select heater type, Fahrenheit or Celsius, and several other settings.

However, if the Wi-Fi dies down, you don’t have to sit without heating. You can then adjust the thermostat using the up and down arrows on its faceplate. But using them requires more force than other touch displays, especially that of the Ecobee 3 lite.

Mysa is also compatible with Amazon Alexa, Google Assistant, IFTTT, and Apple HomeKit. Its vacation mode helps you save energy while you’re away from your home. A lockout mode prevents anyone from tinkering with your preferred temperature setting, and it also tracks your energy usage to save money.

One area where this thermostat could have done better is its price. It costs twice as much as a standard programmable thermostat. The cost can go through the roof if you’re planning to have multiple thermostats for multiple rooms. 

Things We Like   

• Feature-rich app
• Hassle-free installation
• Works with line voltage heaters

Things We Don’t Like      

• Pricey

How It Compares With Our Criteria

1. Warranty: 2-year (limited)
2. Accurate Sensor: Yes
3. Programmable Schedule: No

Sinopé Smart Thermostat

• Type: Smart
• Power source: Electric
• Works with: Line voltage heaters
• Interface: Touch

Here’s another smart thermostat that works with line voltage heaters.

Yet it cannot be more different from Mysa. It is less pricey, requires a bridge to connect to your home’s Wi-Fi network, and can handle more load (4,000 watts) than Mysa (3,800 watts). Though it isn’t as aesthetically pleasing and fails to give off high-tech vibes.

On the other hand, Sinopé offers much more information than Mysa. Apart from displaying the current inside temperature (which Mysa also does), it shows the date and day, the programmed temperature, and the current outside temperature (which Mysa doesn’t).

The biggest difference between the two heaters is how they both wire to your baseboard heater. We have already stated that Mysa can be powered using the line wire. That isn’t the case with Sinopé whose internal components require constant electrical power to function.

Both these smart thermostats have equally user-friendly apps, though. The Neviweb app’s main screen displays Connected Platforms, Geofencing and Consumption History. During the setup, it requires you to enter the energy rates in your area to estimate your daily, monthly, and annual energy costs for all times to come. Nice!

Geofencing is another feature both Sinopé and Mysa share. It requires you to set your coordinates and create a 5km radius around your house. Then, whenever you’re within that radius, the thermostat will automatically turn on. It will automatically turn off too once you leave home for the office every day.

That being said, we’d have liked this product better had it included the proprietary bridge in the package. The bridge’s price isn’t negligible and, when added to the cost of the Sinope, makes this thermostat as expensive as Mysa.

Things We Like   

• Estimates daily energy usage
• Can handle more load than Mysa
• Has a simple and clean interface

Things We Don’t Like      

• Requires a separate bridge to connect to your Wi-Fi network

How It Compares With Our Criteria

1. Warranty: 3-year (limited)
2. Accurate Sensor: Yes
3. Programmable Schedule: Yes

What are Hydronic Baseboard Heaters?

Hydronic baseboard heaters use electricity to heat water or oil in a furnace. The furnace is installed in the basement and uses pipes to send hot water into baseboards in multiple rooms. The hot water’s heat then warms the rooms through convection and radiation.

If you want to know if your smart thermostat will work with your furnace, read this article.

These heaters are incredibly efficient when compared with electrical baseboard heaters. It’s because their stored water, when warmed, takes much time to cool down.

That isn’t the case with electric baseboard heaters whose metal fins cool down relatively quickly and require frequent reheating.

Types of Baseboard Heaters

Electrical and hydronic are two main types of baseboard heaters:

Electric baseboard heaters

Electric baseboard heaters sit in the middle of your room, suck cold air from their surroundings and raise the air’s temperature by passing it through a series of metal fins. These fins are hot due to conducting electricity and transmit their heat to the air.

As the air’s temperature rises, its density falls. This causes the air to rise and leave the heater and warm up your home. Electric baseboard heaters are easy to install, operate quietly and have low installation cost. Their only shortcoming is that they consume a lot of electricity.

Hydronic baseboard heaters

Hydronic baseboard heaters, as mentioned above, heat water or oil in a furnace located in the basement. The stove uses pipes to transmit the heated fluid to your rooms, where the fluid’s heat warms up its surroundings through radiation and convection.

The unique selling point of the best hydronic baseboard heaters is that they can keep the fluid heated for long periods, even hours after the thermostat has turned the heater off. However, when compared with electric baseboard heaters, hydronic baseboard heaters cost much more and are slow to start.

How to Choose Thermostats for Hydronic Baseboard Heaters

Here’s how you can select the best thermostat for hot water baseboard heat:

Low Voltage Vs Line Voltage Thermostats

Low-voltage thermostat

Low voltage thermostats use less power, operate under 30V, and have thinner wiring than their line voltage counterparts. You can use them to control virtually any kind of baseboard heaters, heat pumps, air conditioning, furnaces, boilers, or radiators.

Provided you’re warming up your home by generating heat in one furnace and then transferring the heat to other rooms via ducts, low voltage thermostats should be your preferred choice. That’s because their electricity consumption is negligible.

Pros

• Use less electricity
• Lower running cost

Cons

• Cost more upfront
• Relatively difficult to install

Line voltage thermostat

Low voltage thermostats consume more electricity, powered by either 120- or 240-volt circuits and have thicker wires than their low voltage counterparts. You can quickly identify them by a pair of two (or four) black and red thick wires coming out of their face.

These thermostats are much more tolerant of temperature fluctuations and it might take changes of up to 7*F to make them respond. As a result, they are commonly used with hydronic baseboard systems, oil-fired hot boilers and localized heating systems.

Pros

• Plug and Play Installation
• Cost less upfront
• Don’t need a transformer to convert voltage

Cons

• Use more electricity

Single Pole Vs. Double Pole

Line-voltage thermostats come in two types: single pole and double pole. The term ‘pole’ refers to how many circuits the thermostat (or switch) runs off one circuit.

Single pole

Single pole thermostats run on one circuit, which means they supply the power to the unit in one direction only. They have two wires connecting to the main circuit. One of the wires is attached to the thermostat and the other is attached to the baseboard heater.

That is the reason why single pole thermostats don’t offer a true ‘off’ function. That means that they’d keep on supplying current to the baseboard heater even when you turn off the thermostat, as long as you don’t switch off the breaker.

How to identify single pole thermostats? Two wires will be coming out of their back

When should you use a single pole thermostat? Since it won’t turn the heater OFF completely and will turn it ON once the temperature falls below a setpoint – forcing you to move things away from the heater to prevent potential fire, it’s a better choice for those who don’t leave their home for long periods.

Double pole

Double pole thermostats run on two circuits, which means they supply the power to the heater in both directions. They have four wires and both of their hot wires are attached to the thermostat. That’s not the case with single-pole counterparts, which have only two wires and attach one of those to the baseboard heater.

This is why double pole thermostats are capable of offering a true ‘off’ function. Once you interrupt the electric current supply to the thermostat, no current will be passing to the baseboard heater. This makes them a more energy-efficient option than single pole thermostats.

How to identify double pole thermostats? Four wires will be coming out of their back

When should you use a double pole thermostat? Those of you who want their heater to have a true off function should use a double pole thermostat.

Manual vs Programmable vs Smart Thermostat

Here are the differences between manual, programmable and smart thermostats:

Manual Thermostat

Manual thermostats maintain the temperature which you initially set unless you manually re-adjust it. They cost less upfront and are easier to install than both programmable and smart thermostats. That’s where the good news ends.

These thermostats aren’t quite accurate and thus consume more energy. Also, every time you enter or leave the house, you’d have to adjust the thermostat. Failure to do so might send your heating bills through the roof. Poor accuracy and huge energy consumption are their biggest drawbacks.

Pros

• Cost less upfront
• Are easier to install

Cons

• Aren’t quite accurate
• Consume more energy

Programmable Thermostat

Programmable thermostats have the ability to adjust the temperature according to preset settings. For instance, you could set a programmable thermostat to maintain a room temperature of 65 degrees throughout the day, and 72 degrees from 6:00 p.m. to 11:00 p.m. every night.

This allows programmable thermostats to provide two benefits. First, they save you money by automatically adjusting the thermostat based on the temperature of its surroundings. Second, they provide comfort by providing the perfect temperature while you’re just reaching home or asleep.

Pros

• Provide more comfort
• Ensure more energy savings
• Let you set a multi-day heating schedule

Cons

• Higher upfront cost

Smart Thermostat

Smart thermostats can be controlled with a smartphone, smart speaker, tablet, or other internet-connected devices. You can also control them from voice-operated smart home systems like Alexa and Google Home.

These thermostats can cut down your heating bills by as much as 20%. That’s because they automatically adjust the thermostat’s temperature based on preset levels and your schedule. They also send energy usage reports, maintenance reminders and system operation updates to your smartphone.

Pros

• Cut down heating costs
• Can be controlled remotely
• Send periodic system updates to your smartphone

Cons

• Require 24*7 Wi-Fi

Frequently Asked Questions

Q: How do heater thermostats work?

A: Mechanical heater thermostats work by taking temperature changes into account. They have either a metal strip or a bi-metal coil and a mercury-filled vial. When temperature changes, the strip or coil moves, causing the mercury-filled vial to follow suit.

Depending on the direction (right or left) the mercury is flowing towards, either heating or cooling will be turned on.

Q: What is the best smart thermostat for baseboard heaters?

A: In my opinion, the Ecobee 3 Lite is the best smart thermostat for baseboard heaters. You can control its operation from anywhere in the world, set heating schedules and monitor your energy usage via the Ecobee app. It’s also Energy Star® certified and will bring about a visible reduction in your heating bills.

Q: What is the best thermostat for hot water baseboard heat?

A: The Honeywell Flexible Programmable Thermostat is the best for hot water baseboard heat. That’s because it offers a day-to-day programmable schedule, sends air filter change and low battery alerts to its display and automatically adjusts the heater’s temperature based on your needs.

Q: Can you replace a thermostat with any thermostat?

A: You cannot replace every thermostat with any aftermarket model.

Take the example of line voltage thermostats. They are capable of handling more power and cannot be replaced with their low voltage counterparts which cannot handle as much wattage. That’s why you must check whether your existing thermostat is low voltage or line voltage before buying its replacement.

Q: When should I replace my thermostat?

A: Here are signs you should replace your thermostat:

1. Your heating bills have suddenly increased
2. Your heater keeps turning on or off
3. The thermostat is giving faulty readings
4. Your thermostat cannot maintain its settings for long
5. You haven’t replaced your thermostat for years
6. Your heater turns off too early and fails to complete its cycle

Q: How long do thermostats last?

A: The majority of thermostats don’t last more than 10 years. After a decade, the accumulation of dust and aging wiring might cause the thermostat to malfunction. This will harm the performance of both the thermostat as well as your heater, necessitating replacement.

Conclusion

I hope this article has given you everything you need to know about thermostats for hydronic baseboard heaters. Now the onus is on you to take the next step and select the model which best meets your requirements.