09 2025 GT 1 Series Plumbing and Bath Features

Kitchen Sink:

The Tiffin GT Series kitchen is a leap into bold innovation, where the benefits of a stainless-steel single bowl sink with a built-in sprayer (Figure 9-1) go beyond aesthetics, transforming your space into a fortress of style and utility.
Stainless steel is known for its durability, resistance to rust, and ease of cleaning, making it a reliable choice for busy kitchens. The single bowl design offers plenty of space for washing large pots, pans, and baking trays, which can be challenging in other sinks. The built-in sprayer adds extra convenience, allowing you to rinse dishes effortlessly and clean hard-to-reach areas. With its sleek design and functional features, this type of sink enhances both the practicality and style of your kitchen setup, making everyday tasks more efficient and enjoyable.
Keeping the single-bowl sink and built-in sprayer faucet clean is simple, requiring only regular maintenance and gentle cleaning to preserve its functionality and appearance. Begin by rinsing the sink and faucet with warm water to remove debris. Use a mild dish soap and a soft sponge or cloth to gently scrub the surfaces, steering clear of abrasive materials that could scratch the stainless steel. For stubborn stains or mineral buildup, applying a vinegar-water solution can be highly effective. Allow it to sit for a few minutes before wiping clean. Dry the sink and faucet with a soft towel to prevent water spots and finish with a stainless-steel cleaner for a polished look. Regular maintenance like this keeps the sink and faucet in excellent condition.

Shower:

The Tiffin GT Series is designed with a private bathroom that combines luxury with functionality. It features a custom fiberglass shower with an integrated sink (Figure 9-2), offering a seamless and durable design. A wraparound shower curtain provides enhanced coverage, while a shower door adds an extra layer of privacy. The space also includes a built-in toilet paper holder (Figure 9-3) for convenience. One standout feature is the adjustable mirror (Figure 9-4), which can be rotated for use inside or outside the shower, allowing for maximum flexibility and ease of use. This thoughtfully designed bathroom ensures comfort and practicality while maintaining the upscale feel of the Tiffin GT Series.

Shower Operation:

Tiffin GT Series features a ShowerMiser (Figure 9-5), an innovative and highly efficient system engineered to enhance water conservation. Its main purpose is to conserve water by redirecting cold water that would typically go down the drain while you're waiting for the hot water to arrive. Here's how it works:
Recirculating Cold Water: When you turn on the shower, the cold water is rerouted back into the freshwater tank instead of being wasted in the gray water tank.
1. Indicator System: The ShowerMiser has a color-changing indicator (Figure 9-6) that lets you know when the water is hot and ready for use.
2. Simple Operation: To operate the system, simply adjust the lever (Figure 9-7) ensuring a seamless and user-friendly experience.
This system is especially useful for dry camping, as it helps extend the capacity of both your fresh and gray water tanks.

Shower/Sink Faucet:

The Tiffin GT Series features a versatile shower sink faucet (Figure 9-8) designed for both convenience and functionality. This innovative fixture extends seamlessly, allowing it to function as a handheld sprayer when detached. For showering, the faucet can be securely attached to the designated holder on the shower wall, transforming into a stable, hands-free showerhead. This dual-purpose design maximizes space efficiency while maintaining the vehicle’s sleek, modern aesthetic, ensuring a refined and adaptable bathroom experience.

Water Pump:

The water pump is used to pressurize the freshwater system when the unit is not connected to city water.

How to Start the Water Pump
1. Fill the Freshwater Tank
• Completely or partially fill the freshwater tank to ensure an adequate supply.
2. Open Faucets
• Turn on both the kitchen and bathroom faucets to allow air to escape from the system.
3. Power On the Water Pump
• On the home screen of the Spyder control panel, simply click the water pump icon (Figure 9-9) to activate the water pump and let it run until the water fills the lines.
4. Close Faucets Gradually
• Once a steady stream of water flows, close each faucet, starting with the cold-water faucet first.
• Leave the hot water faucets open until they also deliver a steady stream, then close them.
5. Pump Operation Check
• The pump should automatically shut off when all faucets are closed.
• It will run when a faucet is opened and stop when the faucet is closed.
Important Maintenance Notes
• Avoid Dry Running: Never let the pump operate for extended periods without water in the supply tank, as this can cause damage to components or blown fuses.
• Drain System When Not in Use: If the van will be unused for an extended time, drain the entire freshwater system to prevent buildup or damage.

Here are some troubleshooting tips for water pump on the Tiffin GT1 Van:
Common Issues & Fixes
1. Pump Won’t Start
• Check if the pump is receiving 12V power.
• Inspect loose wires or a blown fuse.
• Ensure the switch is turned on.
2. Pump Runs But No Water Flow
• Verify that the freshwater tank is full.
• Check for clogged filters or blocked hoses.
• Inspect for air leaks in

the system.
3. Pump Won’t Shut Off
• Look for leaks in the plumbing system.
• Ensure the pressure switch is functioning properly.
• Check for air trapped in the lines.
4. Low Water Pressure
• Clean or replace clogged faucet aerators.
• Inspect for kinked hoses or blockages.
• Check if the pump diaphragm is worn out.
5. Pump Cycles On & Off Frequently
• Look for small leaks in the system.
• Ensure the pressure tank is working correctly.
• Check for faulty check valves.

Sewer Bay:

The sewer bay of the Tiffin GT Series is strategically positioned on the driver’s side, discreetly concealed behind a magnetized access panel for a streamlined and unobtrusive exterior design. This thoughtfully integrated compartment ensures easy access while maintaining the vehicle’s sleek aesthetic, offering a convenient and efficient solution without compromising style or functionality.

Sewer Bay System Overview:

The operational guidelines for the Sewer Bay valve system are as follows:
• City Water Supply – Rotate the yellow handle (Figure 9-10) to the city water position on the left to supply water directly from an external source into the vehicle.
• Fresh Tank Mode – Rotate the yellow handle to the fresh tank on the right to run the water system using the fresh tank instead of city water.
• Ensure Proper Valve Positioning – Always check the handle orientation to optimize water usage based on the desired function.
Filling the fresh tank on the Tiffin GT Series:
• Turn the yellow handle to the fresh tank position to direct water flow into the tank.
• Connect an external water hose to the city water fill port (Figure 9-11) to supply water.
• Allow water to flow until the fresh tank is full.
• Turn off the water supply and disconnect the hose once filling is complete.
• Return the yellow handle to the appropriate position based on your desired water system operation.
This process ensures a smooth and efficient way to replenish your freshwater supply.

Sanitizing Hot and Cold Fixtures and Freshwater Tank:

To assure complete disinfecting of the freshwater system, it is recommended that the following procedures be performed on a new system, on one that has not been used for a length of time, or one that may have become contaminated. This procedure is also recommended before long periods of storage, such as during the winter months:
1. Drain the freshwater tank by opening the drain valve. All the faucets should be in the closed or “off” position.
2. Prepare a chlorine solution using one gallon of water and one-half cup of chlorine bleach (5% sodium-hypochlorite solution). Prepare enough of the chlorine solution to administer one gallon of solution for every 15 gallons of tank capacity. Concentrations greater than 50 ppm may damage the water lines and/or the tank.
3. Once the freshwater tank is empty, close the drain valves to the water tank.
4. Connect one end of the vinyl hose to the city water fill port on the sewer board; place the other end of the hose into the solution that has been prepared.

5. Turn “on” the water pump. On the sewer board turn the yellow handle valve to the “fresh tank” position.
6. Open each faucet, in turning “on” both the hot and cold faucets and flushing the toilet until all the air has been purged from the pipes and the water runs freely. The entire system will then be filled with the sanitizing solution.
7. Allow the 50-ppm disinfecting solution to stand in the system at least four hours.
8. Drain the system and flush it with freshwater. The water system needs to be flushed with water repeatedly, until there is no chlorine taste or smell left in the system. To remove any excessive chlorine taste or odor that might remain, prepare a solution of one quart of vinegar to five gallons of water. “Rock” the tank containing the solution; by moving the vehicle forward and backward several times to clean the tank; then drain the tank and refill it with clean water.

Sanitizing Hot and Cold Fixtures Only (Not Freshwater Tank):

1. All faucets should be in the closed or “off” position.
2. Prepare a chlorine solution using one gallon of water and one-half cup of chlorine bleach (5% sodium-hypochlorite solution). Concentrations greater than 50 ppm may damage the water lines.
3. Connect one end of the vinyl hose to the city water fill port on the sewer board; place the other end of the hose into the solution that has been prepared.
4. Turn “on” the water pump. On the sewer board turn the yellow handle valve to city water; this will bypass the freshwater tank.
5. Open each faucet, in turning “on” both the hot and cold faucets and flushing the toilet until all the air has been purged from the pipes and the water runs freely. The entire water lines will then be filled with the sanitizing solution.
6. When the sanitizing process is completed, turn the water pump “off”.
7. Allow the 50-ppm disinfecting solution to stand in the system at least four hours.
8. Drain the system and flush it with freshwater. The water lines will need to be flushed with water repeatedly, until there is no chlorine taste or smell left in the system. To remove any excessive chlorine taste or odor that might remain, prepare a solution of one quart of vinegar to five gallons of water. Repeat steps four, five and six to run the solution through the water lines. Drain the system and flush with freshwater.

Sewer Connection and Camping:

The Tiffin GT Series is equipped with a black and grey tank gate valve and dump outlet (Figure 9-12), strategically positioned on the driver’s side behind the running board and discreetly concealed by a magnetized door for a streamlined and sophisticated exterior. This thoughtfully designed placement ensures effortless access while preserving the vehicle’s modern and refined aesthetic.
While using the van, it is crucial to always maintain the black and greywater holding-tank gate valve is in the closed position, except when actively dumping the contents. This practice helps ensure that enough liquid remains inside the tank, which plays a vital role in facilitating an effective and efficient draining process. Keeping the valve closed allows waste liquids to accumulate, preventing premature leakage and ensuring that the waste materials have ample fluid to mix with.
When the time comes to empty the holding tank, having a generous amount of liquid within it promotes a smoother outflow through both the gate and drain valves. The presence of an adequate liquid volume encourages a swirling motion inside the tank, which is beneficial for loosening and carrying away accumulated solid waste. This swirling action helps break down waste deposits that might otherwise stick to the interior surfaces of the tank, minimizing the chances of blockages and making the overall dumping process more thorough and effective.
Additionally, maintaining a closed valve when not dumping reduces the risk of unwanted odors escaping from the tank and helps prevent clogs by allowing solid waste to mix with the liquid over time. It also extends the longevity of the system by ensuring proper waste disposal and minimizing residue buildup inside the tank. By following this method consistently, van users can maintain a more sanitary and hassle-free waste management system, avoiding common issues associated with improper dumping practices.

How to Use the Black & Grey Tank Gate Valve and Dump Valve (Figure 9-14):
1. Open the Magnetized Door – Locate and open the access panel to reveal the dump station.
2. Connect the Sewer Hose – Attach one end of the sewer hose to the vehicle’s dump outlet and the other to the designated disposal site.
3. Drain the Black Tank First – Pull the black tank gate valve handle to empty solid waste, allowing the tank to fully drain.
4. Close the Black Tank Valve – Once empty, push the valve handle back in to seal it.
5. Drain the Grey Tank – Pull the grey tank gate valve to flush out wastewater, helping clean the sewer hose.
6. Close the Grey Tank Valve – Push the valve handle back in once draining is complete.
7. Disconnect & Store the Hose – Detach the sewer hose and rinse thoroughly before storing it in a sanitary location.
8. Close the Magnetized Door – Secure the panel to maintain a clean and streamlined exterior.