The Operating Systems, Lower Level, Interior and Exterior Inspection sections are EXTREMELY condensed versions of those found in our home inspection book: Home Inspection Business From A to Z
Real Estate Appraisers are not required to be home inspectors. However, I will include these sections anyway to give you some basic details about home inspections.
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.
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 instead of a properly sized unit.
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.
Check the oil tank if it's located in the interior of the house and is visible. I prefer interior oil tanks more than underground tanks due to the potential expense of a leak. There have been recent Environmental Protection Agency court rulings about leaking oil tanks that incur stiff fines for the owner of the leaking tanks. It's also expensive to dispose of oil tanks because they're considered a contaminated waste like asbestos and toxic chemicals. If there's an underground oil tank, recommend that a licensed environmental contractor perform tests to find out if there are any leaks. There are a number of different tests to detect a leaking oil tank. Each test has positive and negative aspects to it. A Petro Test by a reputable oil contractor be performed to find out if there are any leaks. A Petro-Test is a pressure test that an oil contractor performs. What they do is seal off the oil tank vents and feed lines and pump air into the tank. They then monitor the pressure in the tank to determine if it drops which would indicate a leak. Another test is a Water Test. If an oil tank leaks there's a good chance water will enter it. The oil contractor will check the tank to find out if there's any water in it.
Determine if any C of O's, (Certificate of Occupancy), permits or surveys are needed in the local municipality with underground oil tanks. Interior and underground oil tanks generally last about 25 to 30 years and longer if they're maintained. If there are a lot of evergreen trees around the area where an oil tank is buried it'll cut down the life expectancy of the tank. This is because these trees add a lot of acid into the soil that rots the tanks quicker.
Check all heating pipe joints for rust or leaking conditions that'll require repairs. You'll usually find some rust unless it's a new unit.