Saunier Duval 623 Boiler timer

[ITguy_uk]

I have a Saunier Duval 623 combination Boiler which is approx 10 years old (getting on I know) which was in the house I recently purchased. Recently every few days I have found the clock loses (small black digital clock on front) the time of day and all the settings for the different intervals (Heating on and off). I know the power has not failed as our video clock e.t.c still has the same time and is on the same ring main. Initially it cleared the clock to 00:00 and now it resets to 12:00

I am also sure it has also changed from a 24hr clock to a 12hr clock with AM/PM instead of 13:00,14:00,15:00,16:00.

I have looked on the web, spoken to Saunier Duval and spoken to several heating engineers and all they seem to come up with is it has a fault with the timer. I also found on the web and have been told that these boilers timer switches were notoriously troublesome and expensive to replace.

From looking underneath the front panel of the boiler the small black clock in the front is run from a PCB which I assume is the timer unit and has some sort of memory to store the intervals. The connectors seem to just be push fit block connectors and the PCB is just screwed to the chassis of the boiler

Has anyone had a similar problem with this boiler and have the tried replacing the timer unit themselves?

Any hints or info would be appreciated.

[raden]

In message , ITguy_uk writes

Replace the button cell

[ITguy_uk]

Raden,

I didn't think there was a battery in the timer unit (small black digital clock on front of boiler). When I turn the power off to the boiler the display gradually fades and then clears. The timer is a small black digital unit (3-4cm square) and I assumed the power came from the mains ie when the power goes off so does the timer.

I can't see a button cell on the PCB or anywhere else so I assume the button cell you are referring to is in this timer? I did have a look but I think if it does have one it must be inside the case of the timer.

Off to have a look to see if I can find it.

Thanks for info

[ITguy_uk]

After some further investigation the battery for the clock is soldered onto a small PCB (With relay e.t.c for switching boiler on and off) which is attached to the timer clock by three wires. It looks as though to replace the battery the small PCB (not the main one) which I believe is part of the timer unit will have to be replaced (my soldering is not that good!).

Question is does the timer kit include this PCB with the battery?

[raden]

In message , ITguy_uk writes

Ah yes, the other sort ...

I have some at work or can do it for you

phone me -

[ITguy_uk]

Raden,

Thanks for the advice, I got the tagged NiCd battery in the post last week, removed the old one and soldered the new one on. After a slight panic when the digital clock read 88:88 with all the digits on, the battery charged and the clock now keeps it's time, settings and reads correctly.

With your assistance the my boiler repair bill went from £164 (£90 for timer unit and £50 labour+VAT)to £2!!.

Thanks again for the advice and getting the battery to me so quick.

[raden]

In message , ITguy_uk writes

No problems, glad to be of service