Whenever you purchase a new heating system, the primary factors to consider are: the efficiency rating of the system, the type of fuel you are going to use, how the heat will be distributed throughout the house and what size system to buy. By upgrading to a new boiler, you could save considerable amounts of money on heating throughout the life of the new equipment.
If you are considering purchasing a new boiler, you may wish to consider the following best practices:
Improve air sealing and insulation. Before buying a new boiler, make every effort to improve the energy efficiency of your home. Consider sealing air leaks, looking at the efficiency of your windows and the insulation in your ceiling and walls, and checking for insulation opportunities around hot water pipes. Such improvements will save money on heating your home by reducing the loss of heated air to the outside, thereby reducing the demand for heat on your boiler.
Evaluate the cost-effectiveness of a new boiler. If you have an older boiler in your home, it is cost-effective to upgrade to a higher efficiency level if the difference in boiler price is not more than the amount you will save over its lifetime. A boiler's efficiency is shown by the Annual Fuel Utilization Efficiency (AFUE) rating. In general, higher efficiency units have an AFUE rating 80% to 90%. Steam boilers must heat the water to a higher temperature, and therefore have lower efficiencies than hot water boilers. Natural-gas-fired boilers are more efficient than oil-fired boilers.
Consider buying an ENERGY STAR®-qualified boiler. They have an AFUE rating of 85% or greater and can achieve even greater efficiency with enhanced features, including:
- Electric ignition, which eliminates the need to have the pilot light burning all the time
- New combustion technologies that extract more heat from the same amount of fuel
- Sealed combustion that uses outside air to fuel the burner, reducing draft and improving safety
- High-efficiency pumps for moving heated water through the system
Consider a combination boiler. Combination boilers combine domestic water heating and heat generation in one unit. These can save considerable money on heating and water heating costs. The heating part of the combination boiler works in the same fashion as other boilers.
Size your new boiler accurately to realize maximum savings. Have a contractor do a heat-loss, heat-gain calculation to ensure that the boiler you purchase is the best one for your home. Among other important considerations, make sure that the calculation takes into account size and configuration of your home; levels of insulation in walls, ceilings and second floors; the number and types of windows in the home; and orientation of the home to the sun.
Use a programmable thermostat. Programmable thermostats can be purchased from your local hardware or home improvement store. Choose a thermostat with at least four different settings for each day so you can adjust for times you expect to be out and times you expect to be asleep.
Choose a thermostat with different settings for weekdays and weekends if you have a consistent schedule during the week and a different schedule on the weekends. If you work an unconventional schedule, you may want to consider a thermostat that is 7-day programmable, meaning you can set each day differently.
Make sure your thermostat has a hold/vacation feature to allow you to "set back" your temperature setting when you'll be gone for an extended period of time. Consider leaving your furnace off when the home is unoccupied and using the setback feature to minimize unnecessary operation of the furnace.