My sister has a Baxi Solo 2 80PF wall-mounted boiler installed and has been working OK for about 4 years. She recently said that the system had packed up therefore she got some plumber round to have a look. What a waste of time. He said he had fixed it but the boilerwas exhibiting the same symptoms. Let me explain...
I had a look over the system and had noticed the fuse on the PCB for the pump was blown. When the PCB was turned on and CH and HW was called for, the boiler on light would come on and that was it! Nothing else happened. A plumber came and replaced the PCB and Hey presto, the system sprung into life. He therefore left (10AM in the morning). The system was turned up full to 6 on the boiler. At approx 4.30pm that afternoon the same day, I was aware of this horrible shreaking sound coming from the boiler. First thing was to turn the boiler off, so turned off the CH and HW switch on the wall, no change the boiler stayed on exhibiting this awful noise. Turned off the switch on the boiler PCB hence to reset it, no change... Eventually had to pull the fuse out of the mains fuse box to stop the system completely. The boiler did feel quite hot and it stopped!!! Left the system for at least 20 mins to cool down. I did notice that with all the radiators turned up full and with the boiler on all the time, there was not once when the boiler turned off with the Overheat LED lit, not once... This horrible noise was so loud and deafening it was obviously coming from the boiler... I then hard-wired the pump directly to 240V AC and checked it's impedence 45 Ohms, pump started with no problems. Then I dismantled and removed the Fan, hard-wired it too and it was working perfectly. A friend suggested that I bleed the system from the highest point in the house which I therefore did and yes, quite a lot of air came out. Started the boiler up again and it was fine for about 2 hours then the same problem occured again. CAN ANYONE PLEASE HELP AS THIS PROBLEM IS DRIVING US NUTS!!!!!!!!! If anyone requires any further info, please don't hesitate to ask...
I had a look over the system and had noticed the fuse on the PCB for the pump was blown. When the PCB was turned on and CH and HW was called for, the boiler on light would come on and that was it! Nothing else happened. A plumber came and replaced the PCB and Hey presto, the system sprung into life. He therefore left (10AM in the morning). The system was turned up full to 6 on the boiler. At approx 4.30pm that afternoon the same day, I was aware of this horrible shreaking sound coming from the boiler. First thing was to turn the boiler off, so turned off the CH and HW switch on the wall, no change the boiler stayed on exhibiting this awful noise. Turned off the switch on the boiler PCB hence to reset it, no change... Eventually had to pull the fuse out of the mains fuse box to stop the system completely. The boiler did feel quite hot and it stopped!!! Left the system for at least 20 mins to cool down. I did notice that with all the radiators turned up full and with the boiler on all the time, there was not once when the boiler turned off with the Overheat LED lit, not once... This horrible noise was so loud and deafening it was obviously coming from the boiler... I then hard-wired the pump directly to 240V AC and checked it's impedence 45 Ohms, pump started with no problems. Then I dismantled and removed the Fan, hard-wired it too and it was working perfectly. A friend suggested that I bleed the system from the highest point in the house which I therefore did and yes, quite a lot of air came out. Started the boiler up again and it was fine for about 2 hours then the same problem occured again. CAN ANYONE PLEASE HELP AS THIS PROBLEM IS DRIVING US NUTS!!!!!!!!! If anyone requires any further info, please don't hesitate to ask...
andyou want to know what to do about a noise. WHich bit of boiler is it coming from 
