Truma Combi Cleaning

Truma Combi Cleaning

So, we finally tackled the task of Truma Combi cleaning in our beloved Lance 2075.   The process descales the water heater (removes hard water deposits) and should be done periodically.   The Truma manual recommends cleaning every six months.  

Because this was our first time to do this, we were quite late to the task.  I was a little intimidated by it, but it was surprisingly easy.  Additionally, we combined the Truma Combi cleaning with our annual Fresh Water Sanitation process.

Reasons for Truma Combi Cleaning

Unquestionably, the cleaning and decalcification process brings many benefits.  It:

• Reduces sediment buildup which can limit heat transfer and make the heater work harder.
• Improves heater efficiency and also lifespan.
• Reduces the likelihood of leaks related to sediment corrosion on the inside of the tank.
• Promotes a more consistent water temperature.
• Helps prevent clogged pipes and faucets.

Needed Items

• White Distilled Vinegar
• Clean Gallon Jug
• Funnel
• Measuring Cup

Vinegar, citric acid (1 Tablespoon per liter of water), or decalcification tablets can be used.  Because we had vinegar on hand, that was what we used.  So, we were happy we didn’t have to buy anything special for this purpose.

Truma Combi Cleaning Process

Preparation

1. Firstly, drain all water from the fresh water tank and from the Truma Combi.  There is a yellow plastic lever on the bottom left in the Truma compartment that opens and closes the drain.  When empty, close  the fresh water tank and Truma drains.
2. Next, using a gallon plastic container,  mix a solution of water and vinegar that is 1 part vinegar and 5 parts water.  My reference to the mix is in a screenshot below and a link  is here.
3.  The ratio worked out to be 2.66 cups of vinegar for each gallon container.  Per the Truma Combi manual (see screenshot below), the Combi holds 2.64 gallons.   Therefore, we used 3 gallons of the mixture to ensure we had an adequate amount to fill the water heater.

Filling the Tank

3. Pour the mixture into the fresh water tank using a funnel.  You will need a total of three gallons of the mixture. 

4.  After that, draw the water into the hot water heater by turning on the water pump and briefly turning on a single faucet for hot water.  You will hear the water pump run for a short while and ultimately stop.  This means it is filled with the solution.

5.  Use the water pump to circulate the solution through all taps including the shower, toilet and also the outside water sprayer.  Pump just enough water to begin a flow.

6. Leave the solution in the heater for 4-5 hours.

Rinsing

7. Again, drain the Truma Combi and the fresh water tank and then close the drains.

8.  Now, put at least 3 gallons of water into the fresh water tank for rinsing the Truma Combi.

9. Turn on the water pump and draw some fresh water through all faucets and the toilet.

10.  Lastly, empty the Truma and the fresh water tanks and then close the drains.

YOU HAVE NOW CLEANED AND DESCALED YOUR TRUMA COMBI!

I did a good bit of research on line and reviewed the Combi manual.  The reference below apparently has information from Truma via an email.  It was most helpful and contributed to our process.

Reference 

In Conclusion 

I am so glad we have taken care of this maintenance item.  The hardest part was determining just how we would accomplish it.  Therefore, it is going to be a routine task going forward.

Happy Camping!