M
MrMad1966
Folks .. REALLY REALLY appreciate some thoughts here I’m a little demented ATM. Let firstly get out of the way I am not gas reg but do have a significant engineering background so feel more than comfortable tackling the jobs I am allowed to do. I make apologies in advance for a little long winded post but I feel a comprehensive description of actions taken to date are important.
I have a Biasi Riva Advance HE M110B.32SM combi fitted a few years ago. Currently, the CH works fine no problems but DHW fails to heat. Using the service manual and the temp/relationship graphs I quickly discovered I had a faulty DHW probe which was duly replaced (at this point I discovered I had a dirty system too L), so ALL radiators have been removed/jet washed/ Sentinel X400 and flushed through thoroughly. The DHW will now work fine if I manually depress the primary circuit flow switch that is attached to the diverter valve, but I quickly found the spindle on the diverter valve is NOT extending in DHW mode, after previous experience on other boilers I then decided next course of action would be to replace the diaphragm and other diverter components using the diverter repair kit. I was surprised to find the old one was still intact with no tears, so no resolution so far. As it was a “dirty system” I then removed and cleaned the plateX some but not a massive amount of iron oxide rubbish in there so took the decision to just replace instead of clean to rule out any potential restriction issues, still no resolution, not even the smallest sign of extension from diverter spindle. Biasi tech help although very helpful advised me to feel the top left of the plateX (incoming primary flow) and compare with top right, as the top right was cooler they suggest a restriction in the system. As everything works fine in CH mode I am at a bit of a loss as to where this possible restriction could be. Only really the pump and primary heat exchanger left or am I totally off base ?
I have a Biasi Riva Advance HE M110B.32SM combi fitted a few years ago. Currently, the CH works fine no problems but DHW fails to heat. Using the service manual and the temp/relationship graphs I quickly discovered I had a faulty DHW probe which was duly replaced (at this point I discovered I had a dirty system too L), so ALL radiators have been removed/jet washed/ Sentinel X400 and flushed through thoroughly. The DHW will now work fine if I manually depress the primary circuit flow switch that is attached to the diverter valve, but I quickly found the spindle on the diverter valve is NOT extending in DHW mode, after previous experience on other boilers I then decided next course of action would be to replace the diaphragm and other diverter components using the diverter repair kit. I was surprised to find the old one was still intact with no tears, so no resolution so far. As it was a “dirty system” I then removed and cleaned the plateX some but not a massive amount of iron oxide rubbish in there so took the decision to just replace instead of clean to rule out any potential restriction issues, still no resolution, not even the smallest sign of extension from diverter spindle. Biasi tech help although very helpful advised me to feel the top left of the plateX (incoming primary flow) and compare with top right, as the top right was cooler they suggest a restriction in the system. As everything works fine in CH mode I am at a bit of a loss as to where this possible restriction could be. Only really the pump and primary heat exchanger left or am I totally off base ?
