its easy you have to clean the heater exchanger, you will need to remove with an allen key, 2 screws only , and it cames out, after removal add water shake drain ,a few times. garden hose to 1 end and open tap shake . the problem is all the dirt gets stuck inside and there is no room for it to came out, a central heating cleaner is not good enough . i do this every year, and it works.
nelson, December 2009
