Residential Geothermal Storage Tank

Vaughn Model S and ME water heaters with 30 gallon storage or more have both upper and lower heating elements in the tank, and models 20 gallon storage and less have one heating element in the tank.  The purpose of having two heating elementsis to improve the recovery rating in a water heater of significant storage capacity. Sometimes referred to as a “Quick Recovery” water heater, this configuration allows the upper element to heat a much smaller volume of water (about 25% of the tank's capacity) before the lower element takes over. This provides a small amount of usable hot water quickly while you wait for the bulk of the water to heat.  It is worth noting that in the standard dual element design, the upper and lower heating elements are interlocked so that only one can heat at any time, with priority to the upper element.  Once the thermostat controlling the upper element is satisfied (i.e. at set point temperature) the lower element is allowed to heat.  As an option, you may order your Vaughn water heater with the optional “simultaneous operation” feature which allows each element to operate independently, potentially allowing both to be on at the same time in order to increase the recovery rate of the heater.

The Vaughn water heater is constructed with a heat trap installed within the water heater’s hot water outlet connection.  This device helps prevent heat from escaping through the storage tank’s hot water outlet during standby periods, resulting in improved operating efficiency.  The heat trap is constructed from a specially designed bronze nipple with an internal floating ball that during standby periods of no flow settles and closes off the storage tank thereby preventing thermal conduction of hot water radiating through the hot water outlet.

All water heaters constructed using a steel tank requires a lining to protect the internal steel surfaces from corrosion.  Certain linings (i.e. glass and epoxy), due to their nature, have unavoidable holes and imperfections resulting in exposure of the steel tank.   As a result of this deficiency, the manufacturer will install an anode rod(s) in an attempt to delay corrosion of the steel tank.  An anode rod is typically made of aluminum, magnesium or zinc, is a maintenance item that requires periodic inspection and replacement, and is often times the cause of a “rotten egg” odor to your hot water.  Often referred to as a sacrificial anode rod because, over time, it slowly dissolves, sacrificing itself as it is attacked by aggressive substances in the water which would otherwise attack the steel tank through the pinholes and imperfections of the glass or epoxy lining.  A cement lined steel tank on the other hand does not require an anode because of the thickness and guaranteed 100% coverage of the cement lining over all internal surfaces of the steel tank.  This eliminates the need for an anode rod in a cement lined water heater, resulting in a significantly longer life compared to a glass or epoxy lined water heater.

It depends.  The Uniform Plumbing Code (UPC), section 510.5 states In seismic zones 3 and 4 water heaters shall be anchored or strapped to resist horizontal displacement due to earthquake motion. Strapping shall be at points within the upper one-third (1/3) and lower one-third (1/3) of its vertical dimensions. At the lower point a minimum of four (4) inches (102mm) shall be maintained above the controls with the strapping."  If the installed location is in these seismic zones then a strap/restraint system is required.  Otherwise please consult with a plumbing engineer to determine the proper installation method for your water heater.

Yes, Vaughn advises that a drip pan with a proper drainage connection be installed under your water heater.   In some locations drip pans are required by code and in other situations they are highly recommended, but not required.  In either case, if a water heater leak or a dripping relief valve could result in property damage then a drip pan must be installed under the water heater, even when not required by code.

Vaughn uses a blown-in polyurethane foam insulation for all cement lined water heaters and tanks up to 120 gallon capacity. This insulation has an R value of 7.2 per inch. Most Vaughn tanks have a minimum of 2 inches of insulation resulting in an R value of 14. Certain models are available either standard or as an option with 3 inch insulation and therefore have an R value of 21.

The water heater must be stored in the orientation of intended use (vertical, horizontal). The recommended ambient air temperature range is between 50 and 105 degree F and not exceeding 65% Rh. Under no conditions should the unit be subject to freezing temperatures. The unit is intended to be stored indoors, protected from the elements. Desiccant material should be inserted into the electric control panel and heating element terminal house (if applicable). Prolonged storage will require periodic inspection of desiccant. For cement lined tanks only, place approximately 10 gallons of water in the tank before closing and sealing all openings to ensure a humid atmosphere for the lining is maintained. Cap and seal all openings and tank tappings and/or flanges. Provide the necessary protection to ensure the tank and all accessories are protected from physical contact that could result in damage. Shrink wrapping or other suitable protective plastic may be applied to the exterior. Start up and installation guidelines must be followed, with particular attention to testing of the electric heating element.

The HydraStone lining provides guaranteed 100% coverage with a minimum thickness of 0.5” over all internal tank surfaces. In comparison, glass lining is approximately 0.005” thick and includes imperfections, pinholes and variation in coverage thickness resulting in portions of unprotected steel tank exposed to corrosion. In an attempt to compensate, glass lined tanks include a sacrificial anode in an effort to slow down the corrosion of the tank. HydraStone lined tanks on the other hand do not require an anode due to the integrity of the lining. As such, a cement lined tank will far outlast a glass lined tank.

Although we don’t advocate dropping our tanks, sometimes stuff happens. The Vaughn HydraStone lining is a minimum of 1/2" thick (100 times thicker than a glass lined tank) and is guaranteed to uniformly cover 100% of all internal tank surfaces. In essence, the Vaughn HydraStone lining is a tank within a tank and should have no problem withstanding the rigors of shipping and installation. A properly maintained Vaughn tank will last decades.

Legionella is the bacteria responsible for Legionnaire’s Disease, an acute bacterial infection of the lower respiratory tract. This bacterium was first identified in 1977 by the Centers for Disease Control. Pontiac Fever is a less severe, non-pneumonia, flu-like disease that is associated with and likely caused by Legionella bacteria.   Legionella is a fairly common water bacterium and has been found to exist widely in many surface water sources including lakes, rivers, streams and ponds.  It can also be found in ground water sources and some soils.   At the levels found in these naturally occurring sources it typically does not pose a threat to public health.  When the bacterium enters a domestic water system it can find an ideal host environment of warm water temperatures (105-115°F), stagnant water areas (isolated storage tanks and dead-end piping legs) and ample food sources (sediment, scale, deposits and biofilm). Under these conditions Legionella can rapidly colonize, forming higher concentrations that can pose the public health threat of Legionnaire’s Disease.    There are many methods of controlling colonization of Legionella bacteria; a widely accepted and preferred method is to maintain the hot water system storage temperature continually at or above 140°F.  Unfortunately, the elevated temperature necessary to minimize the growth of and kill Legionella bacteria has the potential to cause serious thermal shock and scalding injuries.  As such, many plumbing engineers will specify that the water heater be set to maintain water temperatures at 140°F or higher to reduce the risk of Legionella, but then specify the appropriate mixing valve to ensure safe delivery of hot water to the fixtures.  For a more thorough discussion of Legionella please go to here and the following link to the US Department of Labor OSHA information regarding Legionnaires’ Disease OSHA here

The unique design of the Vaughn heat exchanger electrically isolates the heat exchanger from the tank by means of a non conductive barrier installed between the two. This provides dielectric isolation between the tank and the heat exchanger thereby eliminating electrolysis between the two due to dissimilar metals. This feature is one reason why the Vaughn indirect water heater far outlasts competitor models.

Yes. The heat exchanger is fully removable in all Vaughn indirect water heaters. The benefit to having a removable heat exchanger is that the coil can be removed for cleaning and de-scaling for improved performance and efficiency when used in hard water applications. It should be noted that the heat exchanger is not removable and the coil cannot be cleaned in many other indirect water heater brands.