Faulty central heating programmer

[tshen1bu]

The programmer is a Grasslin Towerchron QE2, purchased from B&Q some years ago. It will not run either a pre-set programme or own set programme, the display is ‘frozen’ and jumbled. It will not accept any effort to reset the day and time.
Any ideas of what the problem may be? I am not technically minded.

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[Animal]

On Saturday, 5 March 2022 at 21:45:08 UTC, tshen1bu wrote:
> The programmer is a Grasslin Towerchron QE2, purchased from B&Q some years ago. It will not run either a pre-set programme or own set programme, the display is ‘frozen’ and jumbled. It will not accept any effort to reset the day and time.
> Any ideas of what the problem may be? I am not technically minded.

Most common problem on small LCD displays is not enough pressure on the edge connectors. If pressing the LCD toward the board unscrambles it, just need a spacer added (eg bit of card) to keep it connecting. Of course there will be live voltages in there so don't do this unless sufficiently expert.

[Martin Brown]

Display jumbled and frozen might be just a contact issue with the LCD
display itself iff the controller still worked and responded to button
presses (or at least *some* button presses). If it has locked up then
either the CPU or working memory is no longer reliable.

Failed electrolytic capacitors tend to cause this sort of fault 10 years
or so from new (ISTR shorter MTBF for some dodgy batches around 2005).
Official policy is no user serviceable parts inside and if you are not
technically minded you are much safer just buying a new one.

Worth trying cycling the power a few times with progressively longer
delays between switching it on again but if it doesn't recover by doing
that then it is WEE scrap and you will need a new CH controller.

ie 10s delay, 1 min, 15 min, 1 hour (then scrap it if no go)

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Regards,
Martin Brown