Greenhouse Boiler Systems: How They Work & Why You Need One

Last updated on September 26th, 2023 at 05:01 am

Having a greenhouse boiler system that runs well and heats the greenhouse to an appropriate temperature is critical to a smooth operation. If you are trying to manage a greenhouse, understanding how a boiler system works and what it does is important, especially when troubleshooting any problems with your system.

This article will provide an overview of how an electric boiler heater and boiler systems work. It will also consider when you should invest in one for a greenhouse.

What is a boiler system?

A boiler system controls the temperature of your building or environment by heating it. There are a variety of boiler heater types that might be selected for a boiler system. 

When looking specifically at greenhouses some potential boiler options include a firebox boiler, a fire tube boiler, and a condensing boiler. Beyond an electric boiler heater itself, other items a boiler system might have include heat exchangers, condensers, piping, pipe insulation, and controls.

What should I know about getting a greenhouse boiler system?

When you are investing in a boiler system it’s important to understand the many different options available to heat a greenhouse. Some considerations when selecting a greenhouse boiler system include:

  • Is the greenhouse new or is an existing boiler system being upgraded 
  • Budget for and cost of the boiler system
  • The types of plants you are growing
  • Utilities required to run the system
  • Available space vs space needed
  • Maintenance requirements

Once you understand your needs, selecting the best boiler system for your greenhouse will become clearer.

What is the temperature range for a greenhouse boiler heater?

It is essential to maintain a greenhouse at an appropriate temperature range to provide optimal conditions for plant growth. As a general guideline greenhouses are normally kept between 70 and 85 ℉ (21 to 30 ℃).

The humidity, season, and types of plants will impact the ideal temperature range for each greenhouse.

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How does a boiler system work?

The way your boiler system works will depend on the type of boiler you have. In general, the boiler uses fuel like oil, gas, coal, or biomass to heat water or turn it into steam. 

The hot water/steam is then pumped through pipes to areas where heat is needed and the heat is distributed. Once complete the water is returned to be reheated at the boiler. Any water loss is replaced with fresh water.

Heat distribution in a greenhouse

Let’s discuss the specifics of heat distribution in a greenhouse that uses a boiler system. Once hot water or steam leaves the boiler, it is pumped to the greenhouse using a pipe system, unit heaters, or a combination of both.

Pipes are placed overhead, under benches, or on perimeter walls. Another option used in greenhouses is pumping hot water and using floor heating for heat distribution.

Lastly, greenhouses also use hot water unit heaters. These units extract heat from hot water or steam at the boiler and send hot air to the greenhouse.  

Types of boiler heaters used in greenhouses

Condensing boilers are the most common boilers used for greenhouses with central heating systems. There are two types of condensing boilers which are fire-tube boilers and water-tube boilers.

A fire-tube boiler heater has flue gas (the hot air produced in the boiler) going through tubes. These tubes are surrounded by water. The water is heated as the hot air passes through the tubes.

A water-tube boiler heater is designed in the opposite way of the fire-tube boiler. Water passes through the tubes, while the hot flue gas surrounds the tubes. The water is heated as it flows through the tubes.

Generally speaking, water-tube boilers are considered a safer choice and have a longer life-span. But, if you have a consistent, reliable, and steady load then a fire-tube boiler might be the better choice for your system. If your load is not steady, then a water-tube boiler is the way to go.

Parts of a boiler heater

Now that we have reviewed how a boiler system works as a whole and options for types of boilers, let’s discuss the boiler and its parts in more detail. This will help you understand how the boiler heats water and steam.

Combustion chamber

This is where air mixes with fuel and combusts, which means the temperature inside the combustion chamber is extremely hot. Temperatures inside the combustion chamber may reach up to 1,000 – 2,000 ℃.

The combustion chamber needs to be made of materials that can handle the hot temperature and pressure seen inside this vessel.


The burner initiates the combustion reaction.There is a nozzle inside the burner that sprays fuel (typically gas or oil) to start the combustion reaction by mixing it with air inside the combustion chamber.

Heat exchanger

The heat exchanger takes the heat produced in the combustion chamber and transfers it to water without contact. This transfer of heat will continue until the water temperature reaches its setpoint.


The control system is the communicator. It sends signals so the boiler knows when more heat is needed and when the water temperature has reached its setpoint.

Other uses for boiler systems

Boilers are used for many heating applications across a wide variety of locations. Besides greenhouses, some other places boiler systems are used include:

  • Houses
  • Office buildings
  • Food plants
  • Paper mills
  • Power plants
  • Textile mills

Whether it’s to heat a building or to provide a heat source during production in manufacturing plants, you can see boiler systems play an important role in providing a reliable heating source.

A greenhouse boiler system that provides optimal temperature control is vital.

Now you understand the specifics of how a boiler system works, including the different parts of an electric boiler heater and how they operate. When using a central boiler system in a greenhouse for heating some options available for heat distribution include piping, floor heating, and hot water unit heaters.

A boiler system is a common and viable option when choosing a heating source for a greenhouse.

Get in touch with us if you are looking for an electric boiler heater or any boiler heater component for greenhouse. A Wattco representative will reach out to you to help you find the most suitable option for your needs.

Your Inquiry, Our Expertise

Don't hesitate to ask questions! Our team of experts is here
to provide you with insightful answers, helping you harness the full
potential of our cutting-edge heating solutions.