Back Boiler common in UK question

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Moved this question to your own thread, it may get views and answers from others familiar with the problem.

Back boilers are very common throughout Europe and when people ask how to heat more area or get more out of their stove in the US, it's usually a waste of time explaining how much heat can be extracted with water. It seems most here only use water circulation with a dedicated boiler instead of adding it on an existing stove. There was no factory hydo system here or in Canada. I believe they were fitted by the owner. Fisher did not make a boiler here like the "Wood Lord" you have available there. We call them "water jacket" or "coils" here. I personally like to use 3/4" stainless pipe as a U shape coil above or on the side of the fire to heat the water directly.
This isn't Fisher specific, but I have experience with steam boilers on locomotives and steam traction engines. Ph is tested and chemicals added to prevent this. I can tell you the copper coils do get sluged up from minerals in the water. Keeping the same material everywhere in the system helps with corrosion from dissimilar metals. A copper coil, copper or iron lines and iron radiators connects the materials together with the minerals in the water. If it has an expansion tank and air seperator, as the water heats, the oxygen in the water comes to the top and is removed. More water (and minerals) is added to keep system filled. This allows the minerals in the water to become more concentrated. With time, the more water is added and oxgen is removed, the higher the concentration of these minerals. (dissimilar to the minerals the iron and copper is made of) This cooks onto the hot heating area as a scale that can clog the system. I never tried automotive radiator flush, but running the system with it in may claen it up, then flush well with plenty of water. I don't know if the stainless doesn't allow the scale to stick, or the heat from the flame direcly on the pipe prevents it from sticking, but mine stays clean. I only have the stainless heat absorbtion area and copper radiation, so keeping dissimilar metals to a minimum may prevent it. If you do have iron and copper in the same system, boiler chemicals should be added.