TRUMA TT2 IN PLACE OF CALORIFIER. Lateral thinking?

[ianj99]

I've just installed one of these 5L water heaters in place of a leaking 25L calorifier. It works great, though I have my doubts just how effective it would be using hot air from a vehicle heater, which is its other unique feature. (I suppose it could be connected into the hot air outlet from a Eberspacher etc to prewarm the contents)

http://ishop247.com/genuine-truma-t...eater-caravan-motorhome.html?___store=default

The TT2 has a 300watt mains heating element which takes about an hour to heat the 5L to 65C (hand hot).

With such a low wattage, it means I can run it off my invertor when the engine is running and 5L is more than enough for dish and hand washing. (No shower on board so don't need more). Its not insulated at all so I plan to encapsulate it in expanding PU foam.

The old calorifier did have a boss for an immersion element but I've never needed 25L of hot water and even though it was insulated, the water never stayed hot for long.

 

[macd]

We fitted a new calorifier last year, and specc'd it with a 500W element precisely so it can be run off modest-sized inverter when motoring. It's also plumbed into the engine cooling system, although there's no reason it must be.

 

[NormanS]

We fitted a new calorifier last year, and specc'd it with a 500W element precisely so it can be run off modest-sized inverter when motoring. It's also plumbed into the engine cooling system, although there's no reason it must be.

But surely if you are motoring, your engine will be producing waste heat. I thought the whole idea of a calorifier was to make use of the available waste heat to give you hot water. Why use the engine to generate electricity, and the pass the electricity through an inverter, then use the electricity to heat a resistance, which in turn will heat the water? There is an efficiency loss at every step.