Changing/Wiring Boiler Programmer

[tntcoder]

Hi,

I'm thinking of changing my boiler programmer, mainly because the current one can't just turn the heating on in the morning... it's either all day or both morning and evening and it has to be on for the same time as the hot water.

This doesn't seem very cost effective, so was thinking of swapping it out. Is there anything to be warey of when doing this? My electrical skills are able to wire a plug but not too much more

I currently have a Honeywell st699 and was going to change to something like this: http://www.amazon.co.uk/Drayton-LP522-Heating-Water-Programmer/dp/5666035363/

Looking at the wiring diagrams for each, it looks like the Honeywell i have now doesn't have a direct earth connection? Is this going to be a problem?

Current Box, no earth?:

Drayton - Junction box needs an earth?

Is that likely to work without me blowing anything up? Hopefully fitting the new backing plate isn't rocket science...

 

[novaenough]

Its been a long day but surely that's an earth connection shown at the top left of the honeywell diagram.
It should be straightforward as all your doing is swapping like for like, just make sure you turn off the power and label everything before you strip out the old programmer. You don't want to get everything mixed up.

edit:
Apologies if that sounds condescending, it wasn't meant too!

 

[HardwareGeek]

Neither programmer requires an earth, the new one just has a terminal to put the earth to keep it neat if you have an earth, the old one might just have the earths in a connector block or have a terminal not shown in the diagram because its not relevant to how it works