Buyers Guide & Information

Best Oil Boilers for Home Heating

We will cover care, maintenance, installation, and review the best boilers for energy efficiency and use currently on the market.

Oil-based heating has been a water and air heating solution in residential homes for over a century. These oil boilers are still being produced and used in homes today because they simply work.

This article will examine the best oil boilers for home heating and explain why they deserve a closer look. We will cover care, maintenance, installation, and review the best boilers for energy efficiency and use currently on the market.

Advantages of Using Oil Fired Boilers

Since 2012, Oil-based heating has switched from diesel to biofuels. These new oils have a lot of advantages and make oil heating more efficient than ever.

  • Ultra low sulfur oil.
    Biofuels now use ultra low sulfur oils that are clean burning and have all of their particulate emissions removed.
  • Burns clean.
    Oil heaters now burn as clean as natural gas, making them great for the environment and your home.
  • Made from agricultural waste.
    Burning oils do not compete with food sources like ethanol does, making the oil and heaters use byproducts instead of consumable products.
  • High energy value.
    Pound for pound oil boilers use up to 50% less fuel than propane or natural gas, giving you better value for your dollar.
  • Multiple fuel choices.
    Biofuels, natural gas, wood, and even vegetable oil can be used in boilers to produce heat.
  • Zone heating capable.
    With the help of control valves and thermostats, you can set up heating zones and save even more energy by only heating the areas that need the heat.

Considerations When Buying an Oil-Fired Boilers

Climate

The climate where you live will play a role in your decision making. Oil boilers are highly efficient (averaging between 86 and 98% efficiency) but are not suitable for all regions. Tropical, dry and moist tropical areas won’t get as much use from a boiler and may find it more cost-effective to use an alternative heating source.

Polar, mid-continental, and highland climates will get the most use and cost savings from oil boilers. You can find your region using the National Weather Service map as a guide.

Fuel Type

Boilers come capable of burning a lot of different fuels. The most common modern boilers use natural gas or propane. However, oil boilers use biofuels and oils, which are more efficient. You can choose biofuels which cost a little more but last a lot longer.

Some models will even burn off any type of oil, including cooking oils, greases from grease trap collections and others, making them ideal for restaurants to help eliminate waste.

Boiler Size

The boiler size is arguably the most important aspect of your decision-making process. Heat is measured in British Thermal Units (BTUs), and the capacity of the boiler is what is needed. You will need to also know the square footage of the home to make a correct fit.

Using the National Weather Service map to find your climate region, you can then get an approximate BTU requirement. A professional installer will use what is known as the Manual-J load calculation to determine the exact requirements of your home. The regional break-down for an informed estimate looks like this:

Zone Climate BTU Recommendation
1 & 2 Hot 15 – 25 BTU/sq. ft.
3 Warm 25 – 35 BTU/sq. ft.
4 Moderate 30 – 40 BTU/sq. ft.
5 Cool 40 – 50 BTU/sq. ft.
6 Cold 50 – 60 BTU/sq. ft.
7&8 Very Cold 55 – 60+ BTU/sq. ft.
Type of Heat Distribution

When it comes to distributing the boiler’s heat to the home and living spaces, you have three basic options to choose from.

Steam Radiators

Steam radiators heat the oil, which heats the water to above boiling. The steam created by the boiling water is pushed through the system to radiators in the rooms.

Hot Water radiators

Hot water radiators work the exact same way as a steam radiator system, except they do not allow the water to exceed 200 degrees (boiling point). Instead of steam, the hot water is pushed through the system to the radiators, which heat the room’s air.

Hydronic radiant heating

Hydronic radiant heating works like a hot water radiator, with the exception being that the rooms do not use radiators but have sub-floor radiant heating tubes instead. The hot water heats the floors, which heat the air in the room, raising the temperature.

Features

There are a couple of noteworthy features, specifically in how the boilers operate. It is essential that you know what to expect from your boiler, especially if you have an older model to replace or have never used one before.

Condensing vs. Non-Condensing

All modern boilers must be condensing styles. You no longer have a choice in the matter. Condensing boilers are self-contained and sealed from outside contaminants. The condensate is no longer recirculated and instead drained away (it has a high acidity level). Condensing boilers are much safer and easier to maintain than non-condensing boilers.

Sealed Combustion vs. Non-Sealed Combustion units

Sealed combustion systems and non-sealed systems are two terms that may come up in your research. Sealed systems are more efficient and cleaner. A sealed system pulls air in from intake vents that extend outside; this means you always have fresh air to heat and circulate.

A non-sealed system pulls in air from the rooms, which has already been heated. This takes away from the heat in the room and actually causes some of the heated air to release outside.

Energy Efficiency

Oil boilers are highly energy efficient. Based on the type of system, hydronic or radiant, as well as the fuel source, you can expect an AFUE rating between 86 and 98%. Virtually all of the energy used to create the heat is put into the rooms to heat the space.

You can also use various accessories to increase these ratings even higher, such as timers, thermostats, and other boiler-based add-ons. Oil boilers don’t cost an awful lot to run because they are so efficient.

You can expect to pay a higher initial cost for the boiler system and the initial fuel load (most regions have a minimum 150 gallon fill fee). Once the system is paid for, installed, and the fuel tank is full, though, operational costs are much lower than electrical heaters and on average with natural gas units.

Noise Level

One of the downsides of owning and operating an oil boiler is the noise level. While steps are taken to dampen the noise, you still have a large blower motor and exhaust system that makes a lot of noise.

Even being on the floor above, the noise reverberates through the structure of the unit (often steel or aluminum) as well as the structure of the home. The motor and blower sounds are also pushed through the ducting and piping along with the water and air.

Style & Aesthetics

One thing oil boiler heaters are not known for is their stylish and sleek appearance. Most units are mounted in closets, basements, or even in the garage out back. However, with modern technologies, the boilers are getting smaller and easier to install.

This also leads to some better looking units, though we doubt you will want to center your home’s décor around them.

Safety Features

All heaters need to have safety features, and depending on the type, this will vary. Portable electric heaters will have tip-over auto shut-off features, for example. But you don’t have to worry about an oil boiler tipping over.

Instead, you want to look for things that make the boiler safe. Thermal overload protection, oxygen level sensors, ignition safety switches, and cool-touch exteriors are the most common. Each one will help the unit perform better, last longer, and prevent damage should something happen. The more safety features there are, the better you can feel about your purchase.

Price & Warranty

The price of the unit will also play a large factor in your decision-making process. Oil boilers are not cheap, and they need a licensed contractor for installation. All told, you will spend at least $2000, and possibly as much as $7000. Your budget needs to be thought out, planned for, and maintained.

Knowing what to look for, where you can save money, and how to best go about buying and installing your new oil boiler will be crucial. The warranty is also highly important.

You need to understand the warranty, what it covers, how long it covers each part, and what may void the warranty (DIY install, for example). You also need to understand the claim process since these aren’t portable heaters you can pack up and ship back. Read all the fine print and make sure you understand everything before you buy.

7 Best Oil Boilers for Home Heating Reviewed

1. MegaSteam MST288

Best Steam Oil Boiler
Efficiency Rating 85% AFUE
Heating Capacity 3000 square feet
Fuel Type Standard oil, some Biofuels
Boiler Size/height, width, depth 33 x 26 x 17 inches
BTU Rating 69000
Material Cast Iron
System Type/Radiator Type Steam

Burnham is an off-shoot company under the US Boiler Company umbrella. Proudly made and serviced in the USA, Burnham boilers are durable and reliable. They offer several models, with one of the most popular being the MegaSteam MST288.

This unit uses 69,000 BTUs (69 MBU) to heat your home through steam-only appliances or radiators. The smaller unit here is cast iron construction with a single-phase boiler offering you about 85% AFUE efficiency.

There is a larger model, the 3-phase MST396SL-HB. This is also a steam-only boiler but comes with a tankless coil for home water heating needs as well. It offers 95 MBU (95,000 BTU) performance to heat your home and water supply.

The chimney vented boilers are all cast iron with anti-corrosion construction to help prevent clogging of the vents, motor, and water pipes. and comes with a decent 10-year warranty on the heat exchanger., The other parts have a limited warranty (some aren’t warrantied at all), so make sure you read through the warranty conditions before you buy.

Contractor installation is available and recommended, especially if you are replacing an older boiler. The install will require certain permits and spacing requirements not available to homeowners or non-licensed persons.

What We Like
  • Produces 99% dry steam
  • Reversible burner door for easier installation
  • Highly efficient steam boiler
  • Barometric draft regulator for better venting
  • Heats home quickly
What We Don’t Like
  • Not the best warranty on the list
  • Removable flue doors can snap hinges

2. Weil MCLAIN UO-5

Best Tankless Oil Boiler
Efficiency Rating 86.5% AFUE
Heating Capacity 2500 square feet
Fuel Type Standard oil (# 2 oil)
Boiler Size/height, width, depth 38.5 x 22 x 32 inches
BTU Rating 196000
Material Cast iron
System Type/Radiator Type Hot water

Weil McLain has several oil boilers in their line up, and one of the best tankless oil boilers is the Ultra-Oil series. The UO-5 is a cast iron hot water boiler that produces a lot of heat very quickly. However, they aren’t as cost-effective as they first seem.

This model includes the boiler and a taco (007) circulator pump but does not have a burner. It is advised to purchase a Beckett oil burner for use, but almost any brand will work. The 6-inch vent and flue help regulate airflow and venting along with the barometric damper to prevent drafts.

Aside from the burner as an extra purchase, these systems are relatively easy for any contractor to install and are best suited for old boiler replacements. In new construction, you may need to install a cement pad or mount it directly to the floor.

The swinging flue doors and burner access make them easy to clean and maintain as well as check on performance and functionality during the annual servicing. The units produce steam, heating as high as 250 degrees; however, the hot water is what is cycled through the system to warm your home.

These three-pass units are highly efficient, hovering around 86 to 87% AFUE, but the warranty is a little light considering other brands in the industry. Still, for a cost-effective oil-fired boiler replacement, they are hard to beat.

What We Like
  • Easy access flue and burner areas for maintenance
  • Ideal for larger homes with radiator heating
  • Tankless system moves up to 22 gallons of water
  • Sealed system for higher working pressure
What We Don’t Like
  • Does not ship with burner
  • Warranty is a little less than desirable

3. New Yorker CL4-126

Oil-Fired Hot Water Boiler
Efficiency Rating 86% AFUE
Heating Capacity 2200 square feet
Fuel Type Standard oil
Boiler Size/height, width, depth 31.5 x 21.5 x 22 inches
BTU Rating 97000
Material Cast iron
System Type/Radiator Type Hydronic

If you are looking for a hydronic boiler to push hot water through your floors or radiators, then the New Yorker CL4 series is for you. When making the purchase, though, be careful which part number you are looking at. The CL4 series uses water and steam boilers, and the only difference in the part number is the ending letter (S or W).

The CL4-126 comes with a built-in tankless coil so you can heat your home’s water supply as well as the radiant heat in the rooms. This adds to the efficiency of the system and can help supplement or even replace your water heater.

The New Yorker system is built from domestic, name-brand parts, cast iron fittings, and low-maintenance burners. One of the most efficient and easily maintained boilers on the market, the CL4 will offer you long life, high heat output, and one of the best warranties around.

With annual servicing costs, the CL4 can also help keep your wallet happy. With top and side access panels, plus a fully open burner door, the entire system is easy to open and clean or replace the burner as needed, lowing labor costs.

What We Like
  • Better all-around warranty than others on the list
  • Tankless coil included
  • Maximized heat transfer with internal shielding
  • All inclusive with no additional purchases required
What We Don’t Like
  • Vent size (7-inches) isn’t conventional
  • Atmospheric venting doesn’t include damper

4. Burnham PV8H7

Top Of The Range
Efficiency Rating 86% AFUE
Heating Capacity 3500 Square Feet
Fuel Type Standard oil
Boiler Size/height, width, depth 32 x 24 x 38 inches
BTU Rating 219000
Material Cast Iron
System Type/Radiator Type Hydronic

For those looking for a large capacity boiler, high efficiency, and easy install, Brunham is it. If you also want a system that is easy to maintain and provides near-instant heat, the Burnham PV8H7 is one of the top of the range models for you.

The price tag is the biggest concern here, but once purchased and installed, you will see significant savings in your monthly energy bills. So much so that it is possible to have this unit pay for itself before the 25-year warranty expires, in just energy savings alone.

This is a multi-faceted system, built as a hydronic heater for radiant floor heating; it can also be configured for hot water or even steam heat to supply your radiators. On top of that, you can also install a tankless coil for heating your water supply and saving even more money in the long run.

Because the system is so efficient and burns the oil cleanly, you get near-instant heat, even in the furthest room. Pushing over 100 gallons at a time, this system will heat your home, garage, and anywhere else you can run the water piping through.

The 1-year parts warranty is a shame, but the heat exchanger comes with a 25-year warranty to make up for it, which is about 10 years longer for an exchanger than most other brands.

What We Like
  • 8-inch flue connection
  • Quietest boiler on the list
  • Push-nipple construction on all burners
  • Tankless water heating coil optional
  • Can be configured for hot water or steam also
What We Don’t Like
  • Only 1-year parts warranty (25-years heat exchanger)
  • Most expensive unit on the list

5. Eliminator

Best Multi-Oil Boiler
Efficiency Rating 95% AFUE
Heating Capacity 1500 square feet
Fuel Type Waste oil
Boiler Size/height, width, depth 30 x 23 x 42 inches
BTU Rating 120000
Material Stainless steel
System Type/Radiator Type Open flame

The Eliminator is a manually operated shop heater designed to use waste oil for heat. Whether you run a garage, kitchen, or other oil-consuming business, your waste oil can now supply you heat in the winter.

The Eliminator works by burning your used motor oil or cooking oil to produce a blue-flame heating source. The 15-gallon tank will hold your oil and burns through just shy of 1 gallon per hour.

The tank must be full when firing but can be replenished at any time. You may need to install a supply line for high capacity shops; manual fill is still required, though. The flame made from burning the oil is started manually with a push button ignition, but you should have a high burning oil in the burner to start.

Note that synthetic motor oil will burn but doesn’t produce a lot of heat. If your shop has mainly synthetic oils, you can mix the oil with diesel and standard oil to increase the heat output if possible.

The stainless steel motor and chamber aren’t as durable as the cast iron models designed for home heating use. However, it still offers a decent warranty covering the casing and ignitor for 90 days, the burner for 1 year, and the heat exchanger for 5 years.

What We Like
  • Burns motor oil, transmission fluid, new and old oil, vegetable oil, cooking oil
  • Large capacity tank
  • LED indicators for oil levels, operation, and temperature
  • Thermostat included
What We Don’t Like
  • All manual operation
  • Won’t burn synthetic motor oil for heat

6. RRO Series 84% AFUE Oil Water Boiler with Coil

Best Value Oil Boiler
Efficiency Rating 84% AFUE
Heating Capacity 3200 square feet
Fuel Type Standard oil
Boiler Size/height, width, depth 22 x 24 x 31 inches
BTU Rating 210000
Material Cast iron
System Type/Radiator Type Hot water

The Rand & Reardon oil-fired boiler is one of the most reliable heating solutions on the market. While it has a slightly lower efficiency rating than other models on this list, it still maintains over 84% at all times (AFUE) and has special features to help heat the home faster.

One of the best additions to this system is the thermal purge functionality from the integrated burner. Basically, any residual warm water in the tank is pushed through the system before the burner ignites. This helps get hot water to the radiators faster.

This unit is also ideal for large homes or multiple rooms, with a capacity above 3200 square feet. The purge system can push a lot of water quickly, and the clean oil burning keeps the water at an ideal temperature for your control settings.

You also get two burner nozzles with your purchase. One is installed, offering 1.5 GPM flow rate and the full 21000 BTU output. However, if you have a smaller home or fewer radiators attached to the system, you can save money by switching to the 1.25 GPM nozzle with a 175000 BTU output.

What We Like
  • Corrosion and chemical resistant construction
  • Wet base mounting
  • Tankless heating coil installed (4 GPM)
  • Dual nozzle option
What We Don’t Like
  • Warranty is quite limited
  • Higher maintenance than other models

7. Liberty Hot Water Oil-Fired Boiler

Oil Fired Central Heating Boilers
Efficiency Rating 86% AFUE
Heating Capacity 2800 square feet
Fuel Type #2 heating oil
Boiler Size/height, width, depth 27.5 x 15 x 32 inches
BTU Rating 131000
Material Cast iron
System Type/Radiator Type Hot Water

One of the best oil-fired central heating boilers comes from Liberty. With an 86% efficiency rating and easy to use control, this model is not only user-friendly but low maintenance and offers inexpensive annual servicing options.

This non-condensing unit features radiant heating for your home, including underfloor radiant heat as well as hot water radiator heating. It will not produce steam, though, so steam radiators will need a different model.

This unit has been upgraded, and while there isn’t a tankless heating coil, you get the new taco 007e circulator. You still need a separate water heater, which is a shame, as this doesn’t help minimize water and electrical use. However, the system is among the highest rated boilers when it comes to efficiency, so you will notice a drop in your power bills after install.

The Taco 007e circulator combined with the Becket burner and nozzles means much lower maintenance, easier cleaning, and less time for annual servicing. You also get a dual viewing window and wide-swing access panels for easier access.

What We Like
  • Warranty is above industry averages
  • Upgraded with newest Beckett burner and taco circulator
  • Low maintenance needed
  • Floor or radiator hot water heating capable
What We Don’t Like
  • Heating coil not included
  • Not available in all areas

How Do Oil-Fired Boilers Work

Oil boilers all work the same, regardless of heating style. The water sits in the tank with a thermometer that is connected to the thermostat and the burner. When the water temperature drops below the thermostat setting, oil is sent from the oil tank through a high-pressure burner nozzle.

The nozzle vaporizes the oil, making the droplets small enough to become combustible. Once the droplets are sprayed into the ignition, they are lit and travel through the burner. The burner, in turn, heats the water in the tank. The hot water (or steam) is then cycled through the system, heating the radiant tubes under the floor or the radiators in the room.

When the water temperature in the tank reaches the set temperature, the system shuts off the burner. The water cycling through will cool as it makes its trip through the pipes and back into the tank. As the water cools and the temperature drops, the burner reignites, and the cycle continues.

Comparing Oil Boilers with Other Home Heating Options

As efficient as oil boiler heaters are, they aren’t the most common form of residential heat. Below are various other types of home heating. Let’s examine them and find out how they compare to oil-fired boilers.

Furnaces

Unlike a boiler, furnaces use heating elements or burners to heat the air instead of water. The hot air is then moved through ducting and out vents by a blower motor. Furnaces are less efficient because of the heat loss through ducting and the larger air intake systems. They also require more regular maintenance compared to a boiler.

Heat Pumps

Heat pumps and mini-split systems work using a refrigerant to draw the heat from the air, much like your central air conditioner does. The difference is that the heat pump is designed to work in both directions. So when it is colder inside, the system runs normally, adding the heat collected from the compressor to the air inside the home.

When it is warmer inside, the heat pump reverses direction and pulls the home’s heat, pushing it outside, lowering your indoor temperature. Oil boilers only work in one direction, and that is to add warmth to the home, not remove it.

Space Heaters

Space heaters are great for instant heat in a small, specific space. Usually only capable of heating up to about 150 square feet (oftentimes much less), they can be powered by electricity, propane, kerosene, and other fuels. Highly portable and capable of keeping you warm, they can’t compare to the whole-home heat from a boiler or its efficiency.

Gas & Electric Fireplaces

Fireplaces burn fuel to make a fire. If you have a gas fireplace, this uses propane or natural gas to create what is called blue flame heat. Fireplaces are cozy and comfortable but use a lot of fuel or electricity to generate enough warmth for a single room. Boilers use much less fuel to heat the entire home.

Wood-Burning and Pellet Stoves

Pellet stoves are fairly efficient and economical as pellets are relatively cheap and burn pretty slow. Wood stoves also put out a lot of heat but require a good amount of seasoned wood to burn efficiently.

The main drawback to wood stoves is the maintenance and limited heat range, often only heating a single room or a small cabin or home. Boilers may cost a lot more to install and set up initially, but are more efficient and heat much larger spaces with ease.

Oil Boiler Heater Safety & Maintenance Tips

Safety and maintenance are a big part of owning and using an oil-fired boiler. While most models have a lower maintenance routine than other heating sources, there is still plenty to do and check on for operational and home safety.

  • Inspect the components.
    Oil boilers don’t age well, and after about 10 or 15 years, many things can go wrong. You should annually inspect the oil tank and water tanks for corrosion and leaks.
  • Use your senses.
    If you smell oil or burning, it is usually indicative of a leak. Hearing whining, gurgling, or other strange noises are also signs of motor or valve damage.
  • Odorless odors.
    Carbon monoxide is extremely dangerous, and though rare with oil boilers, it does happen. Invest in a good CO2 detector to install near the system.
  • Signs of damage or leaking.
    Always pay attention to things that are different. You want to notice if the color or flavor of your water changes, Higher than expected oil consumption levels, grass around the tank dying, and oil around basement drains are all signs of damage or leaks in your system.

People Also Ask (FAQ)

Are oil-fired boilers environmentally friendly & energy efficient?

Oil-fired boilers are highly efficient. Once you get past the initial purchase and installation cost, the operational costs are lower than electricity and propane heating systems. Oil boilers are also highly regulated and more environmentally friendly, burning much cleaner than natural gas systems.

Can oil boilers produce carbon monoxide?

Carbon monoxide is a byproduct of any burning fuel (wood, gas, oil, etc.) that doesn’t burn completely. Oil boilers can produce carbon monoxide, which is a sign something is damaged or needs replacement.

Do oil boilers need servicing?

Annual servicing is highly recommended. During the 1 to 2-hour service call, the contractor should inspect all piping, tanks, and valves. Cleaning the flue and replacing the burner nozzle are also common service expectations. Every 12 months, generally before the start of the cold season in your area, the system should be inspected and serviced.

How long do oil boilers last?

The average life expectancy of an oil boiler is about 15 years. Anything over 10 years old needs increased inspections and maintenance. Oil tanks generally corrode from the inside out, so any tank over 10 years old with visible outer corrosion or rust should be replaced as soon as possible.

Are oil boilers being phased out?

As science and technology advance, we are seeing a rapid decline in the use of fossil fuels. However, this doesn’t mean oil boilers are being phased out. In fact, new biofuels and other forms of oils are being developed to help keep oil boilers active and working for years to come.

How often do I need to refill the oil in an oil boiler heater?

Depending on the size of your tank and how often you use the heating system throughout the year, you can expect an average of about 18 months worth of use. Smaller tanks or those used more often may need to be refilled once a year, while larger tanks can make it two years or more on a single fill.

How much time does an oil boiler take to heat the home?

If you turn the unit on and expect to raise the temperature of the entire home by 10 degrees (Fahrenheit), you should allow at least 3 hours. The size of your home and the rise in temperature you expect will play a factor. On average though, the first 10 degrees will take about 180 minutes.

How do I improve my boiler efficiency?

If you wish to improve your boiler’s efficiency, you can take easy steps to reduce the heating requirements. Lower the heating load by turning off radiators in rooms that don’t need to be heated. Ensure your home has proper insulation in the walls, attic, and even underneath the home. You can also purchase programmable thermostats to help maintain a more constant temperature, reducing the number of times the boiler needs to turn on or the length of time it needs to run.

What is the expected cost to my energy bill?

To determine the average cost of an oil boiler, you need to know a few measurements. First, you need to know how much you are charged per kilowatt-hour for electricity. The national average is about 13 cents per kWh. You also need to know how many watts the system uses in both running and start-up modes. Running boilers use about 300 watts (200 burner motor, 100 watts circulation).

For start-up, you can triple this number, or about 900 watts, though only for a few moments. If you divide the wattage by 1000, you will get the kilowatt rating, which you can then multiply by the number of hours used. Multiply this number again by the cost per kWh to get your average energy fee. Using average numbers, then, we see a 300 watt system, running 5 hours per day for 3 months at 13 cents per kWh costing: 300 watts / 1000 = 0.3kw x 5 hours = 1.5kWh per day x $0.13 = $0.195 per day x 3 months = $17.55 in energy costs for 90 days.

Conclusion

It is no secret that oil-fired boilers cost a lot to purchase and install. However, once installed, their operation and maintenance costs are a fraction of other heating methods. Finding the best oil boilers for home heating can be a challenge, but this article showed you everything you need for a smart, informed decision.

If you are still wondering which model to purchase, take a second look at our top pick. The MegaSteam MST288 Oil Cast Iron Steam Boiler is very low maintenance, easy to operate, and has enough safety features to keep you calm and comfortable.

Josh M
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