The Difference between a Boiler and Furnace
If you’re looking at choosing a new heating system, it’s important to know your options. Equally if you need a service or repair, it’s good to know what you’re dealing with.
You might assume, sure it’s easy I have a furnace… Most people who heat their home with oil will call their system a furnace, when in actual fact they have a boiler; the two are actually quite different.
A furnace heats air which is circulated through the home’s duct system. This is also referred to as a forced air system. The fuel source for a furnace can be gas, electricity or oil.
A boiler heats water which is then circulated through pipework and radiators or baseboard. A boiler also uses gas, electricity or oil to power it.
In short, a furnace heats air, a boiler heats water.
Both systems are capable of providing reliable heating for your home, however variances in air flow can create drafts or cold spots with a furnace; boilers tend to be more consistent.
In some cases a furnace can increase humidity in the home and cause the air to be dry in the winter; in this case a humidifier may be needed. But a furnace makes it easier to cool your home, since the ductwork can be used for air conditioning. If you have a boiler and no ductwork you need to have two separate systems.
Another consideration is for people who have allergies. A furnace can blow allergens/contaminates throughout the house. However, the filters are designed to restrict this; allergen filters can help to reduce the chances of allergies flaring up. To maintain good air quality, ducts need to be regularly cleaned and filters need to be regularly changed.
It is generally considered that boilers are more expensive than furnaces to purchase and install, this is especially true if your home already has ductwork. In some instances, a furnace can be installed within a few hours, compared to a boiler which can take a full day, or more to install.
Both a furnace and boiler are capable of lasting between 15-20 years, but it is the maintenance in between that sets them apart.
A boiler has few mechanical parts and does not need much maintaining, beyond a yearly inspection. In contrast a furnace runs a motor and blower fan which pushes the warm air throughout your home. There are also the filters and ductwork which need regular cleaning every few months.
Boilers and furnaces come with their own list of pros and cons. A boiler for instance can also power hot water for showering, something that cannot be achieved with a furnace.
Ultimately you need to decide which is right for you and your situation.