Choosing Between Steam or Hot Water Heat: Advice for New Homebuyers

The home buying process can be complicated,temperatures and volume for safe and efficient
with many details to consider. Should you buy aoperation. When the thermostat calls for heat, an
house with two stories or just one? Hardwoodoil or gas burner is activated and begins to heat
floors or carpeting? Laminate countertops orup the water in the boiler. Depending on the
marble? When real estate markets are hot, andparticular system, the circulator pump will either
energy costs are stable, buyers have had aactivate to begin circulating the water throughout
history of only looking at the superficial elementsthe house when the thermostat calls for heat or
of the home, with few taking the time to reallywhen the water reaches a pre-set temperature.
analyze the type of heating system that is inMost modern hot water boilers have an automatic
place.feed system. As the water is heated, it expands.
In times where home heating costs are on theThe extra volume is forced into an expansion
rise, knowing what kind of heating system youtank, which helps prevent the build up of
are investing in can be a big deal. The homeexcessive pressure. A pressure relief valve is also
inspection report can let you know what type ofrequired to ensure the boiler pressure does not
heating system is installed in the house, along withreach excessive levels. Boiler temperature and
the age and condition of the system. Knowingpressure can be observed on a gauge mounted
these details about the heating system can helpon the unit. Under normal operating conditions
save you thousands in repair expenses, hightemperatures will range from 160° to 220°F
heating bills or expensive system upgrades.(70-105°C), with water pressure in the 12-18 psi
Water-based heating systems have proven to be(pounds per square inch) range. Readings outside
a reliable source of quiet, even heating for manythese parameters generally indicate that the unit
years. There are two basic types of water-basedshould be checked.
systems to consider: steam and hot water. WhileThe original hot water systems operated by
these systems differ in their operation andgravity flow, with the heated water rising by
controls, they both utilize a boiler as the vessel toconvection through the distribution system. This
heat the water and a piped distribution systemtype system also uses a manual feed valve and
connected to radiators (or convectors) to provideopen expansion tank, usually installed in the attic
heat in the individual rooms of a house. The mostor an upper closet. Gravity systems are rarely
common type fuels used with residential boilersfound in their original state; most have been
are gas and oil.replaced or have been modernized.
Steam Heating SystemsWeighing the Pros and Cons
In a steam boiler, water is heated in much theSteam and hot water systems have an economic
same way as it is in a whistling teapot. As waterservice life of approximately 20-25 years; many
in the partially filled teapot or boiler is heated tooperate beyond that time frame. Regardless of
212°F (100°C), it turns to steam while thethe age or type system, annual servicing is
pressure within the system increases. In a teapot,recommended. One attractive feature of forced
the excessive pressure is vented through a holehot water systems is the ability to break the
in the spout. In a steam heating system, thesystems up into zones, allowing for the separate
steam rises under low pressure (less than 5 psi)control of the heating in the individual rooms or
through the pipes to the radiators. On eachareas of the house. This is done by way of
radiator, an air vent opens as the steammultiple zone valves and one or more circulator
increases the air pressure within the radiator.pumps.
When the steam reaches the vent, it closes. AsAnother type distribution system occasionally
the heat of the radiator radiates to the room, thefound with hot water boilers is referred to as a
steam eventually cools and condenses to water,radiant system. Plastic or metal pipes are installed
and, by gravity-flow returns to the boiler to bein the concrete floor slab or in tracks in a wood
reheated.floor system then covered with finished flooring.
All steam boilers require a pressure relief valveThere are no radiators; the heat radiates from
and a low-water cut off. Most steam systemsthe floor as the concrete is heated. The
have a manual feed valve to allow for the periodicadvantage of this type system is that it provides
addition of water to the system. A "sight" gaugeuniform heating at the lowest or generally coldest
on the side of the boiler indicates the water level.point in the house. Disadvantages with radiant
Water normally needs to be added every fewsystems include difficulty in determining or locating
weeks in order to maintain the water level at theleaks and limitations on the type floor coverings
one half to two thirds full level.used. While carpeting can be used with radiant
A steam system should operate without anyheat, heavy padding and/or carpeting can lower
excessive noise. If there is a "knocking" noise insystem efficiency.
the system, it may indicate partially closed orArming yourself with information about the types
malfunctioning valves or sagging pipes. Constantof home heating systems available can help you
discharging of the air or steam indicates a ventmake a more informed decision about which
malfunction.home is right for you. The level of maintenance,
Hot-Water Heating Systemsexpense, and replacement timeline can have a
Modern forced hot-water heating systems utilizestrong effect on your decision to purchase the
one or more pumps to quickly and quietly circulatehome. Making sure that you know the details
the heated water through pipes to convectors (orbefore you buy can save you a lot of money and
radiators). This type system is a closed system,hassle over the long haul.
relying on the physical relationship of pressure,