Baxi 105e not going beyond 50deg

[pumpz]

hi there

my baxi 105e boiler has started to play up with the heating.

the heating temperature dial on the boiler used to be midway between 0 and halfway and that would see the temperature LED's rise to 70 degrees - the rads would get nice and hot.

now i have to turn the heating dial right up to the maximum level (turn full clockwise) but the LED's wont go beyond 50 degrees

i can't fathom out why this would happen?

the pressure is fine at 1.5 and hot water is fine too

any ideas please?

thanks for your time

 

[pontered]

has the pcb been replaced recently?????

if so it is a common fault to put the thermostat knob in upside down, therefore when you put it to maximum its only on about a 1/3 of its power, pcb needs re-fittin with the knob turned 180degrees

 

[bengasman]

Any problems with the boiler in the past? Has it been serviced annually? Was it installed to spec?

 

[pumpz]

ah yes now you mention it the PCB board was replaced as had issues with hot water (which is now fixed)

am I able to access the PCB board myself to see if the thermostat has been wrong placed? (will obvioulsy switching off the unit and take out the plug from the mains first!)

 

[namsag]

Just turn the knobs from high to low there should still be full movement on them if not spindles have not bee located right and board needs lifting out and engaged correctly onto spindles of stat knobs

 

[Agile]

If the knob has not been forced then you might gat a higher temperature with the knob turned near minimum.

But if they have been forced past the potientiometer end stop it could have damaged them.

If you view the pcb from the inside face you will see a little cutout on the white rotating part in the centre.

That cutout should not turn so that its in between the metal contacts.

Tony

 

[pontered]

i suppose you could access it yourself

it only needs lifting up and the ch knob turning half a turn then refitting

make sure the power is off

alternativley get the guy back who fit pcb to fit it properly

 

[pumpz]

Hi all thx for call the useful replies

The dial does rotate fully as it stands now so I'll take a look at the PCB and will report my findings!

Thx, Cliff

 

[pumpz]

So i got to the PCB... Looking down on it.

I turned the little white pins (called drive pins in the manual) on the CH dial fully anticlockwise then full clockwise and noticed that it didn't turn very solidly, it felt very loose and uneven when turning which makes me think that the actual thing itself on the PCB board is faulty?. When I do the same on the hw it turns much stiffer and just feels correct. (and the hw temp is fine and relative to where i have the dial set)

So could that be the issue in that the actual little ch control thing on the PCB is knackered?

I didn't fully remove the PCB as all the wires threw me abit!!

 

[Agile]

Thats odd!

You went to all the trouble of looking at the PCB but ignored what I had asked you to look at.

I should not have bothered.

Had you discovered it was wrongly fitted and is now damaged the repairer would have had to fit a new one for you!

Tony

 

[pumpz]

I didnt ignore what you suggested!

it was late at night and thought it best to have another look this weekend in natural light!

I read the Baxi manual again and despite the lack of step by step instruction I can see that the PCB board is easily removed via 4 screws and i need to draw down where each electrical block fits back in

as i said in my previous post, it looks like the actual tiny thing on the PCB board that controls the temp setting is faulty, not the entire PCB

Rgds
Cliff