P
pyxyuk
Hello,
My first post and I'm straight into a problem! I have checked the focums but couldn't find an answer so I will try and give as much detail here inthe hope someone can help!
🙁 I have a sort of creeping death in the boiler :
Boiler had been working fine, then the hot water would sometimes not heat up, then over a day or so the HW stopped working and the flame failure light was flashing (twice per second). After a short while longer the CH also stopped heating.
My initial investigation was to check of loose wires etc and performing a reset saw the CH come on for very short periods - such as 10 seconds before the boiler cut out and flame failure flashed. In this state the start sequence for CH was working to the point that the flue fan started and air pressure switch could be heard to operate but then boiler went to flame failure with no ignition - I could not confirm if there had been any spark at the electrode.
The flashing light indicates 'blocked flue or internal failure'. At this point I got an engineer out however neither him nor me have got to the bottom of the problem. In fact, when the engineer came out the next day after boiler had been off all night both the flame on and flame failure lights were slow flashing - a different error - indicating some over temp problem and now, right now, the boiler doesn't even get as far as starting the fan.
So what we have now is:
Demand CH -> pump starts -> hydraulic switch moves and makes on microswitch. Power light is on and both other lights are flashing at a slow rate. A reset does nothing. Boiler doesn't start the fan and no attempt to ignite.
Troubleshooting to date:
The following sensors/switches have been checked:
The microswitch on the hydraulic unit, the flow sensor, the temp sensor - these appear okay although the engineer has questioned the microswitch so he is replacing that tonight.
As a second test on the circuit board connector M2, these switches/sensors have been by-passed in turn (and together) which in theory means if the mircoswitch was faulty then it has been by-passed. However doing this has made no difference the boiler still fails and doesn't start the fan.
The engineer previously thought it was the circuit board and replaced this but again no difference in the error or progress of the start sequence.
There is no difference if HW is demanded (apart from connection across the three way microswitch). Again, no change if the first microswitch/sensors are by-passed.
Final test, perhaps meaningless - the electro-mechanical timer was disconnected from the circuit board and the mircoswitch was by-passed. This resulted in the flame failure light slow flashing - seemingly this is a pump failure - however suspect this is because the timer was disconnected.
The engineer has also checked the flue temp sensor - there is no reset button on this sensor as the manual suggested but a check with the meter suggests this is okay.
The flue is not blocked, the wiring to the fan is correct, the air switch can be heard working and seems okay (but then we are not getting that far now).
Sorry for the long post but trying to give the information that might help. What has been missed, needs looking at etc. The engineer is back tonight to replace the microswitch but I suspect that since by-passing the switch made no difference I am at a loss how replacing that switch will help and the engineer is seriously scratching his head now 🙁
Gas pressure I guess hasn't been checked - engineer has said that the boiler isn't getting far enough for that to be part of this initial problem.
Any advice/suggestions etc?
.....we are approaching a week with no boiler......😡
My first post and I'm straight into a problem! I have checked the focums but couldn't find an answer so I will try and give as much detail here inthe hope someone can help!
🙁 I have a sort of creeping death in the boiler :
Boiler had been working fine, then the hot water would sometimes not heat up, then over a day or so the HW stopped working and the flame failure light was flashing (twice per second). After a short while longer the CH also stopped heating.
My initial investigation was to check of loose wires etc and performing a reset saw the CH come on for very short periods - such as 10 seconds before the boiler cut out and flame failure flashed. In this state the start sequence for CH was working to the point that the flue fan started and air pressure switch could be heard to operate but then boiler went to flame failure with no ignition - I could not confirm if there had been any spark at the electrode.
The flashing light indicates 'blocked flue or internal failure'. At this point I got an engineer out however neither him nor me have got to the bottom of the problem. In fact, when the engineer came out the next day after boiler had been off all night both the flame on and flame failure lights were slow flashing - a different error - indicating some over temp problem and now, right now, the boiler doesn't even get as far as starting the fan.
So what we have now is:
Demand CH -> pump starts -> hydraulic switch moves and makes on microswitch. Power light is on and both other lights are flashing at a slow rate. A reset does nothing. Boiler doesn't start the fan and no attempt to ignite.
Troubleshooting to date:
The following sensors/switches have been checked:
The microswitch on the hydraulic unit, the flow sensor, the temp sensor - these appear okay although the engineer has questioned the microswitch so he is replacing that tonight.
As a second test on the circuit board connector M2, these switches/sensors have been by-passed in turn (and together) which in theory means if the mircoswitch was faulty then it has been by-passed. However doing this has made no difference the boiler still fails and doesn't start the fan.
The engineer previously thought it was the circuit board and replaced this but again no difference in the error or progress of the start sequence.
There is no difference if HW is demanded (apart from connection across the three way microswitch). Again, no change if the first microswitch/sensors are by-passed.
Final test, perhaps meaningless - the electro-mechanical timer was disconnected from the circuit board and the mircoswitch was by-passed. This resulted in the flame failure light slow flashing - seemingly this is a pump failure - however suspect this is because the timer was disconnected.
The engineer has also checked the flue temp sensor - there is no reset button on this sensor as the manual suggested but a check with the meter suggests this is okay.
The flue is not blocked, the wiring to the fan is correct, the air switch can be heard working and seems okay (but then we are not getting that far now).
Sorry for the long post but trying to give the information that might help. What has been missed, needs looking at etc. The engineer is back tonight to replace the microswitch but I suspect that since by-passing the switch made no difference I am at a loss how replacing that switch will help and the engineer is seriously scratching his head now 🙁
Gas pressure I guess hasn't been checked - engineer has said that the boiler isn't getting far enough for that to be part of this initial problem.
Any advice/suggestions etc?
.....we are approaching a week with no boiler......😡