Our Linea 28 has performed faultlessly for the first 3 years but recently it started playing up.
The design is such that if the boiler fails to ignite within 8 - 12 seconds of DHW or CH demand then the boiler will shutdown and go into "lockout". The status LED will turn red and the code "01" will flash on the temperature display. The boiler can be reset by switching it off at the mode selector switch and then back on again.
Occasionally our boiler will behave as if it is in lockout mode, except that the status LED remains green and no error code is flashing on the display. Resetting the boiler via the mode selector switch/dial fixes the problem and the boiler will then fire up instantly.
I have followed the flow charts in the Vokera manual and testing with a DMM shows that the DHW flow switch is closing but the pump is not being energised. The manual suggests that this is a PCB fault and this makes sense, the pump relay being the obvious suspect.
I replaced the PCB a few weeks ago and all was fine until last week. The problem now appears to have returned and testing again shows that when a hot water tap is opened the DHW flow switch is closing but the pump is not being energised. The boiler runs fine after resetting.
I am reluctant to believe I am unlucky enough to receive two PCBs with the same fault. I guess the processor on the PCB could lock up if the power supply to the PCB was dirty but that would be very difficult to prove.
Does anyone have any other suggestions?
The design is such that if the boiler fails to ignite within 8 - 12 seconds of DHW or CH demand then the boiler will shutdown and go into "lockout". The status LED will turn red and the code "01" will flash on the temperature display. The boiler can be reset by switching it off at the mode selector switch and then back on again.
Occasionally our boiler will behave as if it is in lockout mode, except that the status LED remains green and no error code is flashing on the display. Resetting the boiler via the mode selector switch/dial fixes the problem and the boiler will then fire up instantly.
I have followed the flow charts in the Vokera manual and testing with a DMM shows that the DHW flow switch is closing but the pump is not being energised. The manual suggests that this is a PCB fault and this makes sense, the pump relay being the obvious suspect.
I replaced the PCB a few weeks ago and all was fine until last week. The problem now appears to have returned and testing again shows that when a hot water tap is opened the DHW flow switch is closing but the pump is not being energised. The boiler runs fine after resetting.
I am reluctant to believe I am unlucky enough to receive two PCBs with the same fault. I guess the processor on the PCB could lock up if the power supply to the PCB was dirty but that would be very difficult to prove.
Does anyone have any other suggestions?