Help please! Dan Foss TP4000 series thermostat

Hi. I'm hoping for some advice. We have a very ancient thermostat for our radiators in a very old building.

This morning there was no heat and the display was blank, so I've changed the batteries and reset, but I can't change the time to allow the program buttons to work.

After the reset, I get 3 displays in succession. The first says 03:00 Sr, then it quickly moves to 11:00:00 (but it won't let me change this, even if I press + or the up arrow really quickly). It moves on again very quickly to the 3rd display which just has a flashing colon, like the one in the middle of a time display but doesn't show any numbers and won't allow me to add numbers by pressing any of the buttons.

I have managed to change the temperature so the heating has come on but I won't be able to program until I can set the time. Watching the YouTube video Getting Smart with Dad didn't help and ringing DanFoss customer service didn't either. Are there any experts out there please? Thank you

Could just be knackered. Does it have a button cell battery?

ChrisB1982 said:

Could just be knackered. Does it have a button cell battery?

Click to expand...

We know how that feels! No, it works on 2 x AA, replaced this morning.

Have you tried both resets?

ChrisB1982 said:

Have you tried both resets?

Click to expand...

Yes, we've done all of this.

If none of my fellow forum members can help, it might just be time for a new one. Nothing I’ve seen/encountered before.

ChrisB1982 said:

If none of my fellow forum members can help, it might just be time for a new one. Nothing I’ve seen/encountered before.

Click to expand...

Thanks for trying!