Baxi 105e Why

FromMyWay · Jan 22, 2013

Can someone throw some light on this. I have a baxi 105e two weeks ago the CHE changed the pcb as it would not fire up etc. All seemed to work fine, then I noticed that in the mid afternoon I could hear the boiler start up etc. on looking at the panel neither the CH nor the HW was on, only the boiler burner led. Firstly I thought maybe it was the timer set wrong or something, checked that all OK and the boiler comes on at the times selected. Can anyone tell me why the boiler would start up and presumably just preheat the boiler, is there something different about this new PCB, genuine replacement, is there some kind of ECO or other mechanism for this. Any help would be appreciated if someone can point me to where I can get a schematic for the PCB that would also be appreciated.
Thanks in advance

lame plumber · Jan 22, 2013

is it a 105e instant that keeps water hot and ready for instant use?

FromMyWay · Jan 23, 2013

Lame Plumber,

Can you explain how I verify that the 105e is an instant, it never used to do this with the old PCB board installed.

street elbow · Jan 23, 2013

Easy way to tell: is the word "preheat" above the hot water control knob, along with the words "off" at the 12 o'clock position and the word "on" at 9 o'clock if it has it is the 105 E instant if not its just the plain 105E.

David

warrington · Jan 23, 2013

Is boiler in garage?

Plumb Ugly · Jan 23, 2013

As stated by lame plumber most likely the pre heat function for the hot water tha simply wasn't turned on before (its optional). If not call your engineer back

diamondgas · Jan 23, 2013

Integral frost protection or pre-heat if an 'instant' as mentioned .... They'd be my best guess without attending 🙂

FromMyWay · Jan 23, 2013

Well it is a standard then, as there are no markings on the HW switch etc. This problem was not seen when the old PCB was installed only since this was replaced. The new item was genuine part sealed bag etc., although the new board layout was not exactly the same as old, was told this is update. Could it be that the new one is for an 'instant', can you disable this feature on the board with a link or something. Can I obtain a schematic of the boards from anywhere

Billy Bob Bob · Jan 23, 2013

FromMyWay said:
Well it is a standard then, as there are no markings on the HW switch etc. This problem was not seen when the old PCB was installed only since this was replaced. The new item was genuine part sealed bag etc., although the new board layout was not exactly the same as old, was told this is update. Could it be that the new one is for an 'instant', can you disable this feature on the board with a link or something. Can I obtain a schematic of the boards from anywhere

a instant pcb will not work on a 105e they are very different,there is a modification to the new pcb mainly the earth link,i would get your GSR guy back,if you dont have the boiler fitted in a cold place the pcb is at fault

FromMyWay · Feb 3, 2013

Update, I had the board changed by the supplier and had them check if there were any other options like same board for instant, all confirmed this was the correct board. The problem still persists, engineer has again looked and cannot find a fault. Yet the boiler still switches on, boiler only, at differing times as if it is preheating. Any help appreciated.