LIMESCALE IN YOUR BOILER?
by John Welham
You will all be aware of lime scale deposits forming in your kettles at home and in your motorhome. After 5 years’ use we started to see scale forming on tap outlets in both the kitchen and bathroom sinks of our motorhome. Not surprising, given that we have drawn water from many sources over that time, and some of these will have been hard water. These deposits suggested that there would also probably be some limescale deposits within the boiler unit itself. Although the unit does not actually boil water like a kettle, (max temp usually around 60C), there are bound to be local hotspots where scale will form more readily.
Ours is a typical Truma water heater so I turned to the user manual for information. It was very brief, and recommended the use of a Truma proprietary descaler, but gave no advice how best to do it. I then rang the Truma customer care centre at Burton upon Trent. The chap there was very helpful, as I have always found them to be. He recommended a solution of White Wine Vinegar and water, in the ratio of 1 to 5 respectively. Apparently, Truma Germany recommends equal parts of vinegar and water, but he said a weaker solution worked well enough. The process is to fill the boiler with the solution, then heat it up to the maximum temperature ~60C. Leave it to cool, and then drain it and flush through with a couple of refills of fresh water.
Why white wine vinegar and not some domestic descaler? Apparently the latter contain strong chlorates that attack the internal seals of the boiler, whereas vinegar will do the descaling bit without the problems. I recall reading an article in the French Camping Car magazine a couple of years back recommending white wine vinegar, and it appears in the various web forums, where a solution of 1 to 10 is cited as being adequate.
The next trick is how to get it into the boiler. The boiler holds about 12 litres, so I bought 4 litres of vinegar, made up the solution at about 1 to 4, slightly stronger than recommended, and poured the 20 litres into the holding tank. I switched on the pump and opened a hot tap to draw the water into the boiler. The problem was that as the tank level dropped to near empty the pump started to suck air, and as yet there was no steady flow from the hot water tap. I added another few litres of water to the tank, and finally got a steady flow from the tap indicating the boiler was full of solution. The additional water would have diluted the solution, but I was happy that it was still strong enough. The French article recommended disconnecting the vent tube that comes out of the side of the boiler and filling the boiler using a small funnel to introduce the solution to the boiler. If you have a water system that uses a submersible pump, then it should be quite easy to dunk the pump into a container of solution to fill the boiler.
I went through the heating and flushing processes, and job done! There was no after-taste left by the vinegar, and in theory at least, the boiler should be more efficient. As you cannot seeing into the boiler, there is no way of knowing if there was significant limescale deposits in the first place, nor whether the vinegar dissolved them, but I felt better about trying to remove them.
by John Welham
You will all be aware of lime scale deposits forming in your kettles at home and in your motorhome. After 5 years’ use we started to see scale forming on tap outlets in both the kitchen and bathroom sinks of our motorhome. Not surprising, given that we have drawn water from many sources over that time, and some of these will have been hard water. These deposits suggested that there would also probably be some limescale deposits within the boiler unit itself. Although the unit does not actually boil water like a kettle, (max temp usually around 60C), there are bound to be local hotspots where scale will form more readily.
Ours is a typical Truma water heater so I turned to the user manual for information. It was very brief, and recommended the use of a Truma proprietary descaler, but gave no advice how best to do it. I then rang the Truma customer care centre at Burton upon Trent. The chap there was very helpful, as I have always found them to be. He recommended a solution of White Wine Vinegar and water, in the ratio of 1 to 5 respectively. Apparently, Truma Germany recommends equal parts of vinegar and water, but he said a weaker solution worked well enough. The process is to fill the boiler with the solution, then heat it up to the maximum temperature ~60C. Leave it to cool, and then drain it and flush through with a couple of refills of fresh water.
Why white wine vinegar and not some domestic descaler? Apparently the latter contain strong chlorates that attack the internal seals of the boiler, whereas vinegar will do the descaling bit without the problems. I recall reading an article in the French Camping Car magazine a couple of years back recommending white wine vinegar, and it appears in the various web forums, where a solution of 1 to 10 is cited as being adequate.
The next trick is how to get it into the boiler. The boiler holds about 12 litres, so I bought 4 litres of vinegar, made up the solution at about 1 to 4, slightly stronger than recommended, and poured the 20 litres into the holding tank. I switched on the pump and opened a hot tap to draw the water into the boiler. The problem was that as the tank level dropped to near empty the pump started to suck air, and as yet there was no steady flow from the hot water tap. I added another few litres of water to the tank, and finally got a steady flow from the tap indicating the boiler was full of solution. The additional water would have diluted the solution, but I was happy that it was still strong enough. The French article recommended disconnecting the vent tube that comes out of the side of the boiler and filling the boiler using a small funnel to introduce the solution to the boiler. If you have a water system that uses a submersible pump, then it should be quite easy to dunk the pump into a container of solution to fill the boiler.
I went through the heating and flushing processes, and job done! There was no after-taste left by the vinegar, and in theory at least, the boiler should be more efficient. As you cannot seeing into the boiler, there is no way of knowing if there was significant limescale deposits in the first place, nor whether the vinegar dissolved them, but I felt better about trying to remove them.
