Please can you help.
I have a Worcester Bosch 350 Combi boiler that is probably 12 - 14 years old. This used to be serviced by WB on a regular basis before WB no longer wanted to know. The last time it was serviced by WB was probably 3 years ago, I have attempted to keep up the service myself by following WB's online service instructions. I was hoping to squeeze another 2 years out of the boiler before a total revamp. However the boiler has recently developed a problem.
The symptoms are that the boiler fires perfectly on demand from either the CH or the DHW but will then only run for exactly 5 minutes before shutting down. I then have to wait approx a similar length of time before attempting another relight which it will do perfectly well, only to trip again 5 minutes later. These times are fairly consistent. One other feature that I have noticed is that when the boiler is running for the CH and I turn on a hot water tap the boiler responds accordingly with increased burning 'whoomph' however soon as I turn off the hot water tap the boiler immediately trips as if it doesn't like any change in demand (pressure/flow?) The reasons for this tripping are not apparent to me. I should add that I do not have to reset the temperature switch on top to get the boiler away again. The pressure on the gauge (new) is 1.4bar and remains constant through out.
Getting to the limits of my knowledge I called in an 'expert' who 30 minutes later and 70 pounds lighter advised that the Ignition Card needed replacing. I asked him how certain on a scale of 1 to 10... an absolute 10 he exclaimed as I rushed out the door returning with a genuine brand new WB ignition card and another 140 pounds lighter. This was duly fitted by me but alas no difference! I called the expert back who then claimed its 'probably' the gas valve. That was the end of our dealings, I felt I couldn't support his gambling addiction any longer. Another well intentioned expert advised that it was probably the temperature sensors and that I should swap them about to prove this, alas no change. The latest expert advice that I am being offered is that it is probably the heat exchanger (I'm presuming the water to water one?) that is clogged up.
I should add that both pumps appear to be working fine, the air fan and pressure diff switch are also functioning correctly.
I'm getting quite desperate now as this involves the family getting cold and would appreciate genuine help in resolving the issue and that any guidance be limited to purely getting this boiler up and trucking without delay. I appreciate this is not easy from afar. Thanking you in advance.
Date 18-09-2013[/u]
I have a Worcester Bosch 350 Combi boiler that is probably 12 - 14 years old. This used to be serviced by WB on a regular basis before WB no longer wanted to know. The last time it was serviced by WB was probably 3 years ago, I have attempted to keep up the service myself by following WB's online service instructions. I was hoping to squeeze another 2 years out of the boiler before a total revamp. However the boiler has recently developed a problem.
The symptoms are that the boiler fires perfectly on demand from either the CH or the DHW but will then only run for exactly 5 minutes before shutting down. I then have to wait approx a similar length of time before attempting another relight which it will do perfectly well, only to trip again 5 minutes later. These times are fairly consistent. One other feature that I have noticed is that when the boiler is running for the CH and I turn on a hot water tap the boiler responds accordingly with increased burning 'whoomph' however soon as I turn off the hot water tap the boiler immediately trips as if it doesn't like any change in demand (pressure/flow?) The reasons for this tripping are not apparent to me. I should add that I do not have to reset the temperature switch on top to get the boiler away again. The pressure on the gauge (new) is 1.4bar and remains constant through out.
Getting to the limits of my knowledge I called in an 'expert' who 30 minutes later and 70 pounds lighter advised that the Ignition Card needed replacing. I asked him how certain on a scale of 1 to 10... an absolute 10 he exclaimed as I rushed out the door returning with a genuine brand new WB ignition card and another 140 pounds lighter. This was duly fitted by me but alas no difference! I called the expert back who then claimed its 'probably' the gas valve. That was the end of our dealings, I felt I couldn't support his gambling addiction any longer. Another well intentioned expert advised that it was probably the temperature sensors and that I should swap them about to prove this, alas no change. The latest expert advice that I am being offered is that it is probably the heat exchanger (I'm presuming the water to water one?) that is clogged up.
I should add that both pumps appear to be working fine, the air fan and pressure diff switch are also functioning correctly.
I'm getting quite desperate now as this involves the family getting cold and would appreciate genuine help in resolving the issue and that any guidance be limited to purely getting this boiler up and trucking without delay. I appreciate this is not easy from afar. Thanking you in advance.
Date 18-09-2013[/u]
