Suburban SW4DRA - User Manual

Questions and Answers

M
Maria BridgesAug 11, 2025
Why is the water from my Suburban SW4DRA too hot?
- K
  Kevin SolomonAug 12, 2025
  If the water from your Suburban Water Heater is too hot, check the thermostat position and ensure it is properly mounted. Adjust the thermostat position as needed.
N
Nicholas GilmoreAug 19, 2025
What to do if thermostat not shutting off completely on Suburban Water Heater?
- C
  Carly MartinAug 19, 2025
  If the thermostat of your Suburban Water Heater isn't shutting off completely, replace or repair the thermostat.
J
Jillian NelsonAug 27, 2025
What to do if there is lint or dirt in burner tube of Suburban Water Heater?
- D
  Darren DuranAug 27, 2025
  If there's lint or dirt in the burner tube of your Suburban Water Heater, clean the burner tube.
P
Paul WarrenSep 3, 2025
What to do if there are leaves or other obstructions in flue box of Suburban SW4DRA Water Heater?
- G
  Gregory ChambersSep 3, 2025
  If you find leaves or other obstructions in the flue box of your Suburban Water Heater, clear any obstructions from the flue box.

This document is an operating, installation, and service manual for the Suburban Division's Airxcel gas hot water storage heaters, specifically models SW4DRA, SW6DRA, SW4DERA, SW6DERA, SW4DFA, SW6DFA, SW4DEFA, and SW6DEFA. These heaters are designed for installation in recreational vehicles and mobile housing.

The primary function of these devices is to provide hot water. They are gas-fired storage heaters, with some models also featuring a 240 Volt electric heating element for dual-fuel operation. The manual emphasizes safety, proper installation, and maintenance to ensure safe and efficient operation.

Key Technical Specifications:

Capacity: Models are available in two capacities: 15.1 Liters and 20.3 Liters.
Maximum/Minimum Working Pressure: All models operate within a range of 700 kPa (maximum) to 150 kPa (minimum).
Hourly Gas Consumption: All models consume 8.7 MJ per hour.
Test Point Pressure: 2.63 kPa.
Inlet Pressure: 2.75 kPa.
Inlet Pressure (New Zealand): 2.5 - 3.5 kPa.
Jet Orifice Size: 0.84 mm.
Type of Gas: Universal LPG.
Recovery: 40 L/hr at a 45°C rise.
Electrical (for Automatic Gas Ignitor): 12 Volt D.C.
Electrical (for Models with 240 Volt Heating Element): 240 Volt 50 Hz A.C., 1440 Watts, 6 Amp.
Water Inlet Location: 70mm from top dead center.
Cold Water Inlet Location: 55mm from bottom dead center.
Flue Outlet Location: 95mm from RH top edge of unit.
Gas Inlet Connection Point: 40mm from the left-hand edge of the control housing.
Inlet Size: 3/8".

Usage Features:

The heaters are equipped with an automatic ignition device, eliminating the need for a pilot light. Users are instructed not to attempt manual lighting. A crucial safety warning advises users to fill the tank with water before operating the heater, as dry operation can cause damage not covered by warranty.

For models with an electric element, the heater can be operated using either gas or electricity. The electric element is activated by turning on a dedicated circuit breaker, while gas operation involves turning on the gas supply and the 12-volt electrical power to the appliance.

A thermostat maintains water temperature, and a manual reset button is provided for a high-temperature cut-off device, which trips if the water temperature exceeds 82°C. The manual explicitly states that the thermostat is not adjustable and that water temperatures over 60°C can cause severe burns.

A pressure relief valve is integrated into the system, designed to open if the water temperature reaches 98.9°C or if the water pressure exceeds 700 kPa. This is a normal function in closed RV water systems due to water expansion during heating. Users are warned not to plug, cap, or reduce the outlet pressure and temperature valve.

Maintenance Features:

Regular maintenance is crucial for the safe and efficient operation of these water heaters.

Anode Protection: The tank is protected by a magnesium or aluminum anode rod to prolong its life. The anode must be checked every six months and replaced if it's below 50% of its original diameter. Failure to do so voids the warranty. Only genuine Suburban anode rods should be used.
Draining and Storage: The heater must be drained if it's to be stored during winter months to prevent freezing damage. This involves turning off gas and water supply, opening hot and cold water taps, and removing the anode rod to drain the tank.
Water Quality: The manual advises against using bore water, as high salt content will void the warranty. Tanks should be drained and flushed regularly, with frequency depending on the soluble/silt content of the water.
Odor from Hot Water System: Odors, often described as "rotten eggs" or "sulphur water," are not a service problem but can be caused by sulphur in the water supply or bacteria. The recommended solution is chlorination of the water system, followed by flushing with fresh water. A filtering system that removes chlorine is also suggested.
Burner Flame Inspection: If the burner flame burns yellow, it indicates an obstruction in the burner or flue box. A stiff brush is recommended for removing soot deposits.
Gas Inlet Seal: Frequent checks of the grommet on the gas inlet are necessary to ensure a tight seal, preventing moisture and harmful flue products from entering the living area.
Electrical Connections: Periodical checks of wiring and connections are recommended to ensure they are not damaged/frayed and are tight and compliant with codes.
Pressure Relief Valve Operation: The pressure relief valve should be operated at least once every six months to remove lime deposits and verify it is not blocked. Failure to do so can result in the heater exploding.
Air Pocket Maintenance: To reduce water weeping or dripping from the pressure relief valve, an air pocket at the top of the tank can be replenished by turning off the water heater and cold water supply, opening a tap, pulling the P&T valve handle to allow water to flow until it stops, then releasing the handle and turning the cold water supply back on.

Installation Requirements:

Installation must conform to the Plumbing Code of Australia (PCA), local requirements, and AS/NZS 5601.2 and AS/NZS 3500.4. Only authorized persons should perform the installation.

Clearances: The heater and flueway must be at least 25mm clear of combustible materials.
Opening: An opening flush with the floor in the outer wall of the coach is required, with the wall framed as shown in Figure 1.
Carpet Installation: Not to be installed on carpet unless covered by a metal shield at least 50mm wider than the water heater.
Gas Supply: The appliance must be disconnected from the gas supply piping system during pressure testing. Gas connections must be leak-tested with soap and water before operation.
Combustion Air: All air for combustion must be supplied from outside the structure, not from occupied spaces.
Discharge Pipe: A discharge pipe must be mounted at the pressure relief valve, installed through the floor line, left open to free air, directed continuously downward, and in a frost-free environment.
Pressure Reducing Valve: A mains pressure reducing valve with a rating of 350 kPa (50 psi) must be installed in the incoming water line; failure to do so voids the warranty.
Silicone Caulking: Required in several places to ensure an airtight seal, particularly around the door frame and the gas line grommet.
Module Board Mounting: The module board, which is not secured to the water heater, must be permanently mounted by the installer in an accessible location, out of reach of children, and protected from moisture, chemicals, and flammable vapors.
Ventilation: The water heater vent must not be covered or obstructed by any door or slide-out. If obstruction is possible, the door travel must be restricted to maintain a 6" minimum clearance. The appliance is unsuitable for use as a pool heater.
High Altitude Deration: For operation above 4,500 feet, the heater may require derating by 4 percent for every 1,000 feet above sea level. This involves changing the orifice and should be performed by a dealer or authorized service agency.

The manual also includes troubleshooting guides for common issues like sooting, failure to ignite, insufficient hot water, and water being too hot, linking them to possible causes such as regulator malfunction, clogged orifices, thermostat issues, and obstructions in the burner tube or flue box.

The warranty information states a 24-month limited warranty from the date of purchase, covering defects in material and workmanship under normal use and maintenance. It explicitly lists conditions that are not covered, such as normal maintenance, faulty installation, damage from misuse, and issues related to water quality (e.g., bore water). All repairs must be performed by a qualified service agency.