hedonist222 Used to be 1 to 1.2 and 88°
Now after descaling:
89° celcius and 1 bar
I expected the descale to improve the thermosyphon and increase the temp. The problem with a low boiler temperature on an HX is that it affects steaming. Now I did do some testing work years ago, because u had the idea of doing something like the MaraX about 12 years ago, but without a PID in the HX circuit and the ability to boost the boiler from time to time.
What I found was that very low pressure in the main boiler not only affected recovery times, but depending on HX volume could cause the shot temperature to decline. With a boiler running at 1.25 bar, the group gets hot and is flushed down, but then stabilises the water from the HX to a reasonable temp for the shot. When the group is cooler than normal and the HX is smallish, then declining temperature can happen. If you come to the Forum day and want to bring it, we can put my Scace II on it.