Hey guys - I have a water heating system run off the CH, but it is simply a microbore coil inserted into the immersion heater hole in the cylinder that has hot water pumped around it to heat the water in the cylinder like a heat exchanger. However, it has become corroded internally and flow is very low and not performing. The best solution is to replace the cylinder and do it "properly" or just stick an immersion heater in the hole. Does anyone know where I can get a replacement microbore heat exchanger like the original for a quick solution? Combined brains of DIY banter should be able to solve this!! Regards, Tony kendall