TS715si to TS710 Wiring Question

[dan....]

I self-disgnosed my TS715si died (red light on, nothing else happening, display dead) after a couple of flickering power cuts last week - apparently a common issue in those circumstances.

I ordered a TS710 to replace it, believing the backplate was a straight swap. It isn't. The 715 was wired N and L and 1(COM) and 4(NO) with an additional link from L to 1.

NO is 3 on the 710, so I assumed it'd be the same, swapping 4 to 3 and linking L to 1.

It's not. My friendly electrician can't swing by, and I'm fairly sure it's just a case of correctly identifying where to link the terminals. Can anyone help?

 

[CBW]

It would seem that what you did was correct, why doesn’t it work? Unless the common terminal is linked inside, try without the link?

 

[dan....]

Well that's even worse! No power to the unit. Doesn't switch on.

 

[CBW]

Does it take batteries as well?

 

[dan....]

I should add, with the link installed it tripped the fuse, so I removed the link hoping I could safely close up and ask questions. Without the link I'm getting no power, but no trips either.

I assume it has a battery in the unit. There was a red "remove before installation" tag that I pulled out which I'm guessing was the battery isolator.

 

[CBW]

If it tripped the fuse, you may have shorted the new unit and fecked it, or there’s a fuse in a spur that’s popped.

 

[dan....]

I did consider that! Have ordered a second switch so that I have a backup, but wanted to double check it might not be something else

 

[dan....]

Unfortunately I didn't get a TS710, they'd sent an FP720, so I'll never know.

I bought a Honeywell unit which has nicer connections and all seems to be right in the world. It appears to be calling for hot water and the boiler seems to be responding, so hopefully it's sorted.

I appreciate the help though.