Central heating still not working after 3 port valve replacement

[ErinBates]

We originally had a switchmaster SM805 mechanical timer and we swapped it for the centaur c27 programmer. It has worked for the past 8 months and just now started playing up but do you think it may not be compatible?

 

[jackthom]

Sorry how do i check if it is set up for a fully pumped system? Are you talking about the blue wire in the back of the programme?

I'm not talking about the backplate wiring on the wall.

There's a blue wire link on the rear of the programmer itself which must remain connected for your system.

There's no reason why the C27 should be incompatible with your system.

 

[ErinBates]

There seems to be a black plastic thing no blue wire but it is in place

 

[ErinBates]

We have looked at a compatibility guide and it says
N L HWoff CHoff HWon CHon
Sm805 N L 4 2 3 1
Cent, c27 N L 1 2 3 4

from looking at our backplate can you see if our wiring is correct

Im sorry if I'm going off on a tangent here but just want to make sure

 

[jackthom]

If you are getting a new programmer it will come already set up with the wire/jumper in the correct position for your type of system.

 

[jackthom]

We have looked at a compatibility guide and it says
N L HWoff CHoff HWon CHon
Sm805 N L 4 2 3 1
Cent, c27 N L 1 2 3 4

from looking at our backplate can you see if our wiring is correct

Im sorry if I'm going off on a tangent here but just want to make sure

No problem. You've already checked the heating only wiring when you connected the Live wire links to 1 & 4.

A Live link to 3 should give Hot water Only.

Live Links to 3 & 4 will give Hot Water and Heating.

if they all work as expected the system is set up correctly for the C27.

 

[ErinBates]

Thank you, will let you know how it goes.

 

[ErinBates]

Checked all the links and all fine. Put on the new programmer and all working perfect!

Thank you so much for all of your help there is no way we would have known what to do and where to check without your quick replies! Didnt realise but the original c27 we put on was second hand from my dads and on the back it was made in 2004! Maybe some element had gone in it due to its age.

Thanks so much