Boiler FAQ
What size boiler do I need?
The boiler size needed depends on the construction of the house, the size and type of heating system, the geographical location of the house and the amount of radiation in an existing structure (A detailed heat loss study should be conducted by a qualified heating contractor). The number of people, types of fixtures, number of bathrooms and usage patterns of the inhabitants also determine the appropriate tank size.
Does my boiler require maintenance?
Yes, boilers require maintenance. A qualified service technician should perform the maintenance procedure shown in the installation manual on an annual basis.
It is essential that the following is observed at all times:
Keep the area around the boiler free of objects which are flammable or which could obstruct the flow of air into and around the boiler.
Do not store or use sources of hydrocarbons such as bleaches, fabric softeners, paints, cleaners, refrigerants and cat boxes near the boiler. Traces of these chemicals can be drawn into the boiler, causing severe corrosion damage to the boiler and/or objectionable odors.
Do not expose the boiler to large amounts of dust such as that generated by dry wall construction or woodworking.
The owner should visually inspect the venting system on a monthly basis. If any of the following conditions are found, the boiler should be shut down and a qualified service technician called to correct the problem before the boiler is placed back in service:
Loose joints, corrosion or other deterioration.
Condensate leakage
Sags in horizontal runs of vent pipe
(JSE Series only) - Blocked vent switch not attached to external draft hood.
During the heating season, the owner should also perform a monthly visual inspection of the boiler and the surrounding system piping. To do this, remove the boiler jacket door. If any of the following is found, a qualified gas service technician should be consulted immediately:
Deterioration of the visible controls, wiring and sheet metal components
Water leaks
Carbon ("soot") in or near the burner compartment area
Carbon ("soot") in or near the burner compartment area is an indication of a potential carbon monoxide hazard. If carbon is found, the boiler should be shut down immediately and inspected by a qualified gas service technician. The cause of the sooting should be found and corrected before the boiler is restarted.
Failure to regularly blow down the float type low water cut-off can result in severe damage to the boiler.
If it is necessary to either manually or automatically add water to the boiler more than once a month, a qualified gas service technician should inspect the system for leaks or defective vents. Frequent additions of fresh water could result in severe damage to the boiler.
What's the difference between a heating boiler and a furnace?
In general, a "heating boiler" heats the building, using hot water. A "furnace" heats a building, using hot air or "warm air." Don't confuse the two since their means of making and distributing heat, their controls, and their equipment are mostly different.
What's the difference between a hydronic (hot water) boiler and a steam boiler?
A "steam boiler" delivers heat to the occupied space in the form of steam: the boiler literally "boils" water and sends steam rising up through steam riser pipes and through steam radiators in the occupied space. If your heating radiators have valves which hiss and let air escape as heat is coming on your heat is probably being delivered in pipes which circulate steam from the steam boiler up through radiators in the occupied space. For a detailed guide to inspecting and maintaining steam heat systems see.
How is heating boiler efficiency or economy measured? What does boiler AFUE mean?
Each model of heating boiler is assigned an AFUE number. AFUE is an abbreviation for Annual Fuel Utilization Efficiency. In short, the AFUE tells you, for each dollar you spend on energy for heating by gas, oil, or another fuel, just how much of your dollar shows up inside the occupied space of your building as heat. Higher AFUE is better. If your boiler has an AFUE rating of 90, that means that for every dollar you spend on fuel, 90 cents worth of heat is delivered into your building. The remaining 10 cents is lost in inefficiency such as heat that escapes up the chimney along with the products of combustion.
AFUE is not the whole story of heating cost efficiency. A high-efficiency heating system that has not been cleaned and serviced may be running poorly and wasting money. In fact, an 85% AFUE heating boiler that has not been cleaned might be running at an efficiency much lower, perhaps 65%.
Furthermore, if your building is drafty or poorly insulated, you may be delivering heat at high efficiency but losing it from the building much faster than necessary.
Do boilers waste water or energy?
No, they do not waste water because boilers are a sealed system. Modern boiler systems are just as efficient as any gas forced-air furnace.
Do boilers actually “boil” water?
No, boilers in operation today do not boil water. The term “boiler” is a carryover from the past when steam boilers were common, which boiled water to make steam. Today’s boilers are water heaters and typically use natural gas. Most can heat water in a range from 145-190 degrees, depending on the radiation system.
What are the most important things to know about your boiler heating system?
Is your boiler a standard efficiency or high-efficiency model? Standard efficiency is vented in metal pipe. A high efficiency model should be vented in PVC pipe, either off the top or to the side of the boiler.
What kind of radiation do you have? Fintube or baseboard, or cast iron radiators?
Who will assume responsibility for maintaining the boiler? Are you willing and able to learn to do it yourself, or are you going to have a company do the maintenance for you? The U.S. Boiler Company recommends annual maintenance to confirm that the boiler is working safely and efficiently. Annual maintenance also can identify potential problems and prevent a no-heat situation with your boiler.
