switching British Gas RS1 to MEROSS MTS200

[fabioz]

Hi everyone, I've an old RS1 from british gas. I want to switch to Meross MTS200.
this is my RS1

Is it possible i need to connect like wrote here ->https://www.diynot.com/diy/threads/help-wiring-a-new-thermostat-meross-mts200b.618681/

so like:

"
Blue to N
Red to L
Yellow to NO
Additionally...
Add a short link wire between L and COM

Safely isolate the earth wire in a separate terminal block." ??


in my case:
N Blue -> in number 1 in MEROSS
L Brown - > in number 2 in meross
and 3 black cable with little brown -> in number 3 in meross

and bridge with little cable in meross's box between 2 and 5(COM)?

I think I did but it wasn't working. the boiler does not starting when changes in temperature....
Now i've little doubt maybe i've attach in wrong place 3 to 5 and not 2 to 5. In theory I'm sure I got it right but better ask now... before try again...

 

[EFLImpudence]

in my case:
N Blue -> in number 1 in MEROSS
L Brown - > in number 2 in meross
and 3 black cable with little brown -> in number 3 in meross

and bridge with little cable in meross's box between 2 and 5(COM)?

Looks right if I have found the right diagram.

 

[fabioz]

Looks right if I have found the right diagram.

View attachment 321901

I was very silly... I've put 3 with 5 and not 2 with 5. oh dear... thank you for you help and confirm it!

 

[EFLImpudence]

 

[ericmark]

Looks right if I have found the right diagram.

View attachment 321901

It seems there are three versions, this PDF shows all three it would seem version you show is for "water heating" I would assume using a heat pump? It seems this one

is the version for a gas boiler. Not a clue why "water heating" and "water gas boiler" are different? The electric version I think the contacts are rated higher, 16 amp instead of 3 amp, the gas version has volt free contacts, the water heating only has NO and NC contacts but not volt free.

The same problems exist with programmable thermostats able to use the universal back plate, again with three different wiring diagrams for the same back plate depending on it single, duel, or triple zone. with only single zone volt free, just asking for problems.