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Hello all. Been babysitting an old Baxi105e for three years and it's not a disaster but a bit temperamental. Current niggle : first time in the day, the CH side only fires up if the Hot water is run at the tap first for a few minutes. On turning the hot tap off the CH smoothly takes over and continues to temperature. When the CH fails to fire up, the 'Low pressure / faulty pump' alert light comes one, though the pressure gauge shows just over 1 bar and the pump makes no noise and seems fine. Any ideas ? Thanks.

The diverter primary seal is worn out-stretched or split and the pin is sticking etc.
either way service the diverter with a kit.

First thing baxi will look at is how clean is the system and pump. what i would be testing first is thermisters and flow switches check ok.

eventually, it will pack in all together and be the pcb

Many thanks Redsaw - i have changed pcb before and do have a spare in the cupboard ! Glad you are pointing to the diverter as at least i've re-conned that before with a bit of success. Time to dig into that again then. When you say 'primary seal' i'm guessing you mean the diaphragm - or not ? Thanks again.

molegrip wrote: ↑

December 15th, 2019, 9:47 pm

Many thanks Redsaw - i have changed pcb before and do have a spare in the cupboard ! Glad you are pointing to the diverter as at least i've re-conned that before with a bit of success. Time to dig into that again then. When you say 'primary seal' i'm guessing you mean the diaphragm - or not ? Thanks again.

lol yeah, dont know why i put seal
had one a couple of weeks ago, no hot water when heating on, came on fine without heating demand. then it decided to not work at all.
these boilers will be obsolete in next 5 years.

.... i think they were obsolete last week !