Disadvantages of different heat systems:
Forced Hot Air Systems:Forced hot air systems have one main drawback. That is, if the heat exchanger leaks, there will be lethal carbon monoxide and products of combustion coming out of the vents in the rooms.
Steam Systems:Steam systems do not always have an automatic water feed on the system. When this is the case, the homeowner will have to monitor the water level in the boiler to make sure it doesn't get too high or too low.
Forced Hot Water Systems:Forced hot water systems heating pipes can freeze if the heating system fails in the winter. Also, the pipes can leak over time due to rust and corrosion from constantly being filled with water.
Heat Pump Systems:Heat pumps usually need a backup electric coil heater to assist them in very cold weather. This is because they may not be able to heat the house adequately in very cold weather. Heat pumps are mostly found in warmer climate areas and condo units.
The three most common ways to fuel a heating system are: Oil, Gas and Electric. Heating systems generally have a life expectancy of 20-25 years. Heat pump compressors last about 7-10 years. Often heating systems will last longer, especially the old cast iron boilers. However, it's like an old used car, you never know when it can die. There will be many times that you'll find a heating system that is operating past its normal life expectancy. Just tell the client to budget for a replacement in case the system dies in the near future.
Take a quick look at the heating system just to get a feel for it before turning it on for the test. Check for a service card showing the last date of maintenance service for the heating system. The ceiling over the heating system should have a covering of sheet metal or 5/8 inch fireproof sheetrock to help prevent the spread of fires in this area.
See if there's a data plate on the heating system stating how many BTU's it is. The total heating capacity of a furnace or boiler system is usually measured in BTU's (British thermal units) or tonnage. One BTU is the amount of heat that's required to raise the temperature of one pound of water by one degree Fahrenheit. One BTU is about the amount of heat given off by an old-fashioned wood match. An average single family house that's about 2,500 square feet in size should have at least a 125,000 BTU heating system to heat the house adequately. This number will fluctuate up and down based upon many factors. Some of the factors are: how many windows the house has, what type of insulation, if it's a condominium that has a heated condo attached to it on each side, the efficiency rating of that particular heating system, etc. The biggest factors generally are the square footage, the amount and types of windows and insulation in the house. These calculations must be carefully figured out by the heating contractor before they install the system.
There will be times when you find a house with a heating system that's too small to adequately heat in cold weather. Also, if the house has a lower level then your client may want to finish the basement to make a playroom. Another possibility is that your client may be planning to put an addition on the house. Make sure you remind your client that if they plan to heat additional areas of the house, then they need to speak to a heating contractor. Have the heating contractor figure out if the existing heating system is large enough to heat the expanded areas.
You'll also find houses with air-conditioning compressors that are too small to cool the house adequately. These types of problems are caused by an inexperienced contractor who didn't know what he was doing. It could also be caused by a homeowner who wanted to save a few dollars by installing a smaller heating or air-conditioning system.
The flue pipe is used to safely discharge the carbon monoxide and other products of combustion. These gases must be safely discharged from the house. They're lethal gases!!!
Check the flue pipe on gas and oil fired heating systems. The flue pipe is usually located at the rear of the unit. This pipe is used to safely discharge the carbon monoxide and other products of combustion. All gas and oil fired burners discharge these products of combustion. These gases must be safely discharged from the house. They're lethal gases!!! It's similar to having the exhaust fumes from your car discharge inside your house. It'll kill everyone in the house! The sections of the flue pipe must be screwed together for safety. They must have an upward pitch and should not be within four inches of any combustible material, such as wood, to prevent fires.
Some newer heating systems have two plastic exhaust pipes. One pipe has a fan in it to remove the carbon monoxide and unburned gases from the house. These are very efficient heating systems that operate in the 90% efficiency range due to their low flue stack temperature. The temperature inside a normal flue stack is about 400 degrees Fahrenheit. With the low temperature units, the flue stack temperature is only about 100 degrees Fahrenheit. This means that there is a significant savings in the heat loss from the heating system that rises out of the flue stack. Furthermore, some of the newer systems can have a much smaller BTU capacity since they are extremely efficient units.
The drawback to these low temperature units is that they have to be installed exactly to the manufacturer's specifications or else there can be problems. Some problems caused are, that the heating contractor who installs the system only puts in one flue pipe. Also, the second plastic flue pipe brings cool air from the outside into the flue piping system. This cool air tends to condensate and soots up the flue pipes causing them to need frequent vacuum cleaning by a heating contractor.
Find out from the owner how many zones the heating system has. A zone is just an area of the house with a separate thermostat that can have a different setting. It's more energy efficient to have extra zones. There can be one zone or as many as you want to install. Turn up all the zone thermostats to engage the heating system for about 25 to 30 minutes to test it. Check for the installation and proper operation of the emergency shutoff switch. It's usually located on the heating system or at the top of the lower level steps. Often the switch will have a red cover plate. It's used to shut the system off during repairs and for emergencies by overriding the thermostat control. Let's say someone is working on the boiler or furnace. If the emergency shutoff switch is in the off position the burner will not turn on in the event that someone accidentally turns up the thermostat.
After the system has run during the test, remember to lower the temperature settings on the thermostats to what the owner had them set on. You don't want to get any angry phone calls from the seller after you get home complaining that you left his thermostats on 90 degrees. Make sure you check all registers and radiators before you turn down the thermostats. You need to see that they're providing heat in each room.