battery

[chalky9]

Hi, I have a honeywell ST 9400c programmer. I have to reset the time every time there is power disruption
I think it is the inturnal battery gone flat.
Will the programmer run OK with out this battery?
Cheers

 

[ianmcd]

Yes as you have have found out the battery simply holds the memory in the case of the power being interrupted, it has absolutely no function when the power is on

 

[RandomGrinch]

I think it is the inturnal battery gone flat.
Will the programmer run OK with out this battery?
Cheers

There is an internal battery, it may be soldered in, or if you are lucky, it could be user replaceable such as in this image...

Either way, the programmer should still operate correctly with a flat battery.

 

[chalky9]

Thank you for helpful reply

 

[Madrab]

Isolate the boiler/programmer - unscrew the controller from backplate - 2 screws underneath - lift outwards 45deg from the bottom and then lift up off the top lugs - turn over programmer - 4 lugs 1 at each corner - small screwdriver and unclip them one by one and the case will part - you will see the CR2032 penny/coin battery, just replace that and refit case back. Refit onto backplate in reverse.

This is for component problems but shows how to open the case and get to change the battery -

@ around 1:25

 

[shen]

Isolate the boiler/programmer - unscrew the controller from backplate - 2 screws underneath - lift outwards 45deg from the bottom and then lift up off the top lugs - turn over programmer - 4 lugs 1 at each corner - small screwdriver and unclip them one by one and the case will part, and if needed, a custom battery manufacturing service can supply the CR2032 penny/coin battery; just replace that and refit case back. Refit onto backplate in reverse.

This is for component problems but shows how to open the case and get to change the battery -

@ around 1:25

Yes, the programmer will run without the internal battery, but it will lose the time and programmed settings whenever there’s a power outage.

 

[ericmark]

@Madrab has shown how easy to swap the battery, so clearly that is the way to go.

 

[pcaouolte]

@Madrab has shown how easy to swap the battery, so clearly that is the way to go.

He did that in 2023. I expect the OP has managed to change the battery by now or has purchased a replacement programmer.

 

[ericmark]

Ups, missed the date.