This is a very simple yet apparently confusing topic. Many home inspectors and quite a few plumbers and HVAC techs use the terms interchangeably and don’t really understand the difference. The general home buyer gives me a blank stare when I mention the need for and lack of a sediment trap. Sediment traps are found in the gas supply line between the gas shut-off valve and the controls of gas heaters, water heaters, and pool/spa or hot tub heaters. The photo below shows a water heater in use with no sediment trap.
Water heaters are one of those things that are taken for granted because they are generally very reliable. Most residential water heaters in my area (Texas) use either gas or electricity to heat the water which is stored in a tank and reheated as needed. There are also tankless water heaters available that only heat water as it is being used. While most have a warranty period of less than 10 years most last much longer than that. There are some potential problems with water heaters so here are some things to be aware of.
Effective the first of January, 2012 the State of Texas has adopted and supposedly will begin enforcing the 2009 International Energy Conservation Code (IECC). It is hoped that the implementation of this code will "result in the optimal utilization of fossil fuel and nondepletable resources in all communities, large and small". (Quoted from the Preface of the 2009 IECC.)
These things may cause a need to water your foundation. If you use a soaker hose, keep it 18” to 24” away from the slab and allow capillary action to wick water back to the slab. A soaker hose placed against the slab can wash away soil needed for support and/or cause small sink holes under the house. An underground lawn sprinkler system is a great way to add water when needed. Just be sure the sprinklers never spray directly onto the building.
Electric service drops from a power pole to a home should be at least 10 ft. above the ground or 12 ft. above a driveway. The one in this photo is over the ground but just inches away from the driveway. The pole you see propped against the service drop is a 10 ft pole. Obviously this service is way too low.