Recent content by jrling

Thank you both JohnD & David Lewis. As you say, I have the system boiler (actually with the CH pump external not in the case) and it does not have the rubber hoses, but all copper tubing. See attached picture. I have read the flow sensor (black plastic fitting top left), can get gunked up and...

I have a Viessmann Vitodens 100 WBIA open vent system boiler (not combi) 24KW Natural Gas running CH only with a dozen rads, so a high heating load. About 10 years old. Until recently it worked perfectly and the system is unchanged. I run the boiler thermostat at just above the 60C mark on the...