We have a Biasi Prisma 280SE combi boiler fitted. When the hot tap is opened fully (really good flow) the boiler maintains a temp of 60 C but when just the shower is used (big rain can head with mixer on a cool as it will go but still runs very warm) the temp rises to 90 C before it cuts out. I assume this is the high safety setting. The temperature doesn't respond to the position of the settings on the control dial and will do as described no matter what the position of the dial. I have swapped out the main PCB for a known good one and fitted a new thermister on the DHC but the problem persist. The central heating appears to work as it should.
Any advice greatly appreciated.
John
Any advice greatly appreciated.
John