S
sargan
Baxi Barcelona, under service contract - in May this year started giving intermittent ‘explosive ignition’ … when it happens gives a seriously loud bang. This boiler had been upgraded to 100HE spec some years ago.
Multiple visits and loads of parts … fault just got worse – was also now failing to ignite and going into Lock out .. every couple of days.
Another load of parts … including upgrading the burner door so new style 1 piece electrode assembly could be fitted. (and replaced several times)
After multiple no -improvement visits – one engineer found electrodes shorting to Air Box door panel … I supplied him with high temp sleeving …. Stopped shorting but still locking out.
After about a dozen visits one Tech noticed that every time it failed to ignite he could see a flash over on back of ignition board … multiple board changes, individually and as a pair with control board.
Lockout frequency increased to every start cycle – so boiler 100% down for 1 week.
Another Tech found that the harness to the transformer had been badly burnt (burner box seal leak ?) .. and all insulation burnt off harness – replaced transformer & harness. Could be as a result of all the work rather than root cause.
After lot of investigation – Tech found electrode wires had been interchanged (presumably during one of many electrode changes) – causing wrong direction of spark – and maybe damage to cct boards. Baxi really should have non-interchangeable plugs on these leads to prevent such a mix up.
Today again another Tech visit – another pair of cct boards and ignition board harness, still the same …. Intermittently boiler fails to ignite on first strike and as you hear each ‘click’ of attempt you can see a flash over on rear of ignition PCB … in area to rear of where electrode connects.
My assumption is electrode failing to arc … the energy is built up and has to dissipate somewhere – and flashes over on back of board.
This flash over may be the cause of the damaged the boards – or the effect of damaged boards.
List of parts so far …
Initial fault – Explosive ignition
New burner box door seal
New style ceramic burner
New electrodes (twice)
New flame sensor
New electrode harness
New ignition board
Increased to – also intermittent lock out
New burner box door to allow new style electrodes (folded edge type)
New electrodes (new longer style)
New flame sensor
New condensate trap (new style)
Replaced heat exchanger
Replaced flow thermistor
Replaced Ignition board cct board (twice)
Replaced Control cct board
Increased to 100% lock-out every start (flash over)
Replaced flow thermostat
Replaced Ignition board cct board (twice)
Replaced Control cct board
Replaced ignition transformer
Replaced ignition harness
Replaced main harness
Back to – explosive ignition (flash over)
Replaced Ignition board cct board
Replaced Control cct board
Replaced ignition harness
Fault free for 6 weeks
Back to explosive ignition (flash over)
Replaced Ignition board cct board
Replaced Control cct board
Replaced ignition harness
So significant cost of 10 circuit boards, heat exchanger, burner, burner door upgrade … still ongoing.
Has had 23 Tech visits, 9 different individuals, and more than 60 Hrs on site.
Anybody experienced such a fault – thought I would ask as this is dragging on for so long, about the only items not changed are gas valve and fan.
Multiple visits and loads of parts … fault just got worse – was also now failing to ignite and going into Lock out .. every couple of days.
Another load of parts … including upgrading the burner door so new style 1 piece electrode assembly could be fitted. (and replaced several times)
After multiple no -improvement visits – one engineer found electrodes shorting to Air Box door panel … I supplied him with high temp sleeving …. Stopped shorting but still locking out.
After about a dozen visits one Tech noticed that every time it failed to ignite he could see a flash over on back of ignition board … multiple board changes, individually and as a pair with control board.
Lockout frequency increased to every start cycle – so boiler 100% down for 1 week.
Another Tech found that the harness to the transformer had been badly burnt (burner box seal leak ?) .. and all insulation burnt off harness – replaced transformer & harness. Could be as a result of all the work rather than root cause.
After lot of investigation – Tech found electrode wires had been interchanged (presumably during one of many electrode changes) – causing wrong direction of spark – and maybe damage to cct boards. Baxi really should have non-interchangeable plugs on these leads to prevent such a mix up.
Today again another Tech visit – another pair of cct boards and ignition board harness, still the same …. Intermittently boiler fails to ignite on first strike and as you hear each ‘click’ of attempt you can see a flash over on rear of ignition PCB … in area to rear of where electrode connects.
My assumption is electrode failing to arc … the energy is built up and has to dissipate somewhere – and flashes over on back of board.
This flash over may be the cause of the damaged the boards – or the effect of damaged boards.
List of parts so far …
Initial fault – Explosive ignition
New burner box door seal
New style ceramic burner
New electrodes (twice)
New flame sensor
New electrode harness
New ignition board
Increased to – also intermittent lock out
New burner box door to allow new style electrodes (folded edge type)
New electrodes (new longer style)
New flame sensor
New condensate trap (new style)
Replaced heat exchanger
Replaced flow thermistor
Replaced Ignition board cct board (twice)
Replaced Control cct board
Increased to 100% lock-out every start (flash over)
Replaced flow thermostat
Replaced Ignition board cct board (twice)
Replaced Control cct board
Replaced ignition transformer
Replaced ignition harness
Replaced main harness
Back to – explosive ignition (flash over)
Replaced Ignition board cct board
Replaced Control cct board
Replaced ignition harness
Fault free for 6 weeks
Back to explosive ignition (flash over)
Replaced Ignition board cct board
Replaced Control cct board
Replaced ignition harness
So significant cost of 10 circuit boards, heat exchanger, burner, burner door upgrade … still ongoing.
Has had 23 Tech visits, 9 different individuals, and more than 60 Hrs on site.
Anybody experienced such a fault – thought I would ask as this is dragging on for so long, about the only items not changed are gas valve and fan.
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