Below are the most common installation problems we find. All of these installation problems indicate the installer was not licensed or did not know did not follow manufacturers installation instructions.
NO TPR VALVE DRAIN PIPE – TPR stands for Temperature and Pressure Relief. The purpose for a TPR valve is that if the thermostat failed to shut off the heat source, when the water finally boiled under the pressure in the tank a violent explosion would occur.
Because the TPR valve spews super-hot water when it opens to release the tank pressure, the water needs to be directed downward to within about 6-inches of the floor or the ground outside, to avoid scalding someone standing nearby at the time of the discharge. Water heaters come with a TPR valve, but no drain pipe, because the configuration depends on where it is installed.
TPR VALVE DISCHARGE PIPING INCORRECTLY INSTALLED OR MISSING- The pipe must be of equal or larger diameter than the incoming cold water pipe. It should be rated for hot water use and take the most direct route to where it terminates without any traps or fittings, and the end of the pipe cannot be threaded—so it is not easily capped.
NO WHEELSTOP OR PROTECTIVE BOLLARD – If the water heater is installed at the end of a garage, opposite the garage door, there is the potential for a car to be accidentally driven into it, resulting in flooding or even explosion if a gas line is fractured. A parking wheel stop or bollard placed in front of the water heater should be installed.
NO COLD WATER SHUT-OFF VALVE – Like any other plumbing appliance, a shut-off valve is required and it should be placed on the cold water side.
UNPROTECTED ELECTRICAL CABLE – The electric cable that runs from the wall to the water heater needs to be inside a conduit to be protected from damage. The conduit is typically the flexible type. If the water heater is installed in an attic or compartment, protection is not necessary.
DISCONNECT NOT IN-SIGHT OR LOCKABLE – When someone is repairing an electric water heater, they need to be sure that the electricity stays off for the duration of their work. If the main electric panel is within sight of the water heater, the water heater circuit breaker in the panel is acceptable. If the main panel is not within sight, then a disconnect switch, breaker, or pull disconnect box needs to be installed near the water heater OR a locking device installed on the water heater breaker in the main panel.
Also, there is one more old-fashioned disconnect method we hardly ever see anymore: a cord and plug to a wall receptacle within sight. When this method is used, protective conduit is not necessary.
ATTIC WATER HEATER NOT READILY ACCESSIBLE – An attic water heater needs to be safely accessible for service. Getting to it should not involve stepping cautiously on the bottom chords of trusses and crawling over ducts. This means there should be a solid floor 24-inches wide running from the attic hatch opening for not more than 20-feet to a 30-inch by 30-inch level platform in front of the water heater. Also, an attic light and receptacle outlet is required near the water heater, with a switch located near the attic opening.
INSTALLED IN PROHIBITED LOCATION – A gas water heater cannot be installed in a storage room, bedroom, bedroom closet, bathroom, or bathroom closet, to reduce the risk of carbon monoxide poisoning. An exception is allowed if the closet is a dedicated enclosure, with solid, weather-stripped and self-closing door, and an exterior source of combustion air. A gas water heater requires adequate combustion air, a properly aligned draft hood, and resolving conflict of any nearby air-exhaust appliances that may cause a backdraft from the draft hood.
NO CATCH PAN UNDER WATER HEATER – A watertight and corrosion-resistant pan is required under a water heater in an attic or where leakage would cause damage. A drain pipe from the pan must end near the ground at the exterior as indirect waste into the plumbing drain system. When the side of a catch pan gets cracked during installation or from storing heavy items on it, the pan is no longer functional as a leak protection device.
FLAMMABLES NEAR VENT – A minimum of 6-inches clearance from a single wall metal vent for a gas water heater to any flammable material, or minimum 1-inch for Type B double-wall. We typically see foam insulation near the vent hood that is melted.
The items listed are just a few of the problems we find on home inspections.
Written by Turk Schexnayder, licensed home inspector #10679