Toilet full light on your caravan

The Caravan Toilet Full Light: Troubleshooting and Solutions

The “Toilet Full” light in a caravan is a helpful indicator designed to alert you when the waste cassette is nearing capacity. This light is triggered by a simple mechanism within the cassette, primarily a float that rises with the fluid level. As the float rises, a magnet attached to it aligns with a reed switch on a small circuit board, often located at the front of the cassette housing, causing the light to turn on.

However, there are several reasons why this light may not function correctly. Here’s a guide on common causes and troubleshooting methods.

Common Reasons for the Toilet Full Light Malfunctioning

1. Toilet Paper Obstruction
   • One of the most common reasons the “Toilet full light” doesn’t activate is due to toilet paper getting wrapped around the float. This can prevent the float from rising as the cassette fills, keeping the light off even when the cassette is nearly full.
2. Float Damage from Vigorous Shaking
   • When emptying the cassette, it’s natural to give it a good shake to ensure it’s completely emptied. However, vigorous shaking can sometimes dislodge or damage the float, or even cause it to flush away completely, meaning it won’t rise with the fluid level.
3. Rusty Magnet
   • The magnet on the float can become rusty over time, especially if exposed to moisture for extended periods. Rust can weaken the magnet’s properties, preventing it from triggering the reed switch. In this case, the float may rise, but the magnet’s strength may be insufficient to activate the light.
4. Corrosion on the Circuit Board
   • The circuit board, located under the blue flush button or label, can become corroded over time due to exposure to moisture or chemicals. This corrosion can interfere with the connection, stopping the reed switch from receiving the signal when the float rises.

Troubleshooting Steps for the Toilet Full Light

If your toilet full light is not coming on, follow these troubleshooting steps:

1. Test the Light with a Magnet
   • To check if the “Toilet full light” is functioning, hold a small magnet near the circuit board at the front of the cassette housing. This should activate the reed switch, triggering the light to come on. If it does, the issue likely lies with the float or magnet.
2. Check the Fuse
   • If the “Toilet full light” does not come on when testing with the magnet, inspect the fuse located in the cassette housing. A blown fuse could be the reason the light isn’t working. Replace it if necessary and retest.
3. Inspect the Circuit Board for Corrosion
   • Check for any visible signs of corrosion on the connector of the circuit board beneath the blue flush button or label. Corrosion can disrupt the connection, preventing the reed switch from activating the light. Clean the connectors gently if you spot corrosion, or consider replacing the circuit board if the damage is extensive.
4. Examine the Float Mechanism
   • If the “Toilet full light” comes on with the magnet test but doesn’t when the cassette is nearly full, the issue is likely with the float. Open the cassette to check if the float is stuck, missing, or if the magnet is too rusted to activate the reed switch. You may need to clean the float area or replace the float or magnet.
5. Replace the Circuit Board if Needed
   • In some cases, the reed switch itself may be faulty. If you’ve ruled out issues with the float, magnet, or fuse, it might be time to replace the circuit board. A new circuit board with a working reed switch can resolve the issue entirely.

Preventative Tips

• Regular Cleaning: Make it a habit to clean out the cassette thoroughly, as toilet paper can easily become tangled around the float. This helps ensure the float remains free-moving and unblocked.
• Gentle Handling: When emptying the cassette, avoid excessively vigorous shaking, which can damage the float. Instead, tip the cassette carefully to empty it.
• Check for Corrosion Periodically: Regularly inspect the circuit board and connectors for any signs of corrosion. A quick wipe-down can help prevent buildup and keep your light working.