Because an electric water heater has a longer recovery time, its size should be between 50 and 60 gallons. Necessary features on a water heater are a shut-off valve and a temperature and pressure relief valve. Check water flow from all fixtures in a house for pressure and leaks. You can often see evidence of leaks by looking for stains on sinks, around handles, and in cabinets under sinks. The DWV system drains waste from sinks, baths, and toilets and provides a means of venting the system to the atmosphere.
Test drains by filling up sinks and releasing the stoppers and by flushing toilets.
If some fixtures drain slowly or not at all or if waste material returns, there may be blockage somewhere along the drain lines. If the home is served by a septic system, ask the present owner for records that indicate tank and field location and size, as well as information regarding the most recent tank pumping. Septic systems require maintenance and special treatment. The purchase contract should include a stipulation that the septic system must work properly for 30-60 days with you living in the home. If the system fails, the contract should outline the limit of the seller's liability.