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cgreen69

I have an old Honeywell st 499 controller with a battery back up that no longer works. I purchased a new battery and asked my plumber to fit it. For some reason this did not solve the problem. I am therefore considering replacing it with the newest version, the st 699.

As someone with no plumbing experience I was debating doing the job myself, assuming that the old unit would pop out and the new one slot into the backplate however have I underestimated the complexity of this task? Should I get a technician to do it?

Thanks
 
As long as you follow the instructions that come with the controller you should be ok. You don't have to be a plumber to connect it. The plumber or the electrician will probably do it a lot quicker though.
 
If you decide to do it yourself take a photo of the existing before you play around with it, then at least you have some reference if things don't go to plan.

Also remember depending on how it's been wired their may be some live wires that aren't Colour coded correctly!
 
The ST699 uses the same backplate and wiring as the ST499. So all you have to do is remove the 499 and replace it with the 699.

Turn the power off while you make the change.
 
The ST699 uses the same backplate and wiring as the ST499. So all you have to do is remove the 499 and replace it with the 699.

Turn the power off while you make the change.
Backplates can also fail, so be prepared to change both and as said, memorise the wiring configuration if you change the backplate
Or ring a heating guy
 
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