New Programmer Not Firing Up CH.

[gibson8206]

Finally changed my old mechanical siemans CH and DHW programmer to a sunvic 207 XLS digital display device. My problem is that I can fire up the DHW, but I'm unable to do likewise with the Central Heating. I have a Potterton Primera F using a mid positional valve and one room thermostat which is definately on. I have kept the original back plate for the new programmer. Could it be a new wiring set up or what? If wiring any idea the config. Thanks in anticipation.

Best wishes from,

Gibson.

 

[D_Hailsham]

Which model Siemens did you have?

 

[gibson8206]

Thanks for the reply D_Hailsham. It's a Siemans RWB2E purchased from good old Wicks.

Best Wishes from,

Gibson.

 

[D_Hailsham]

It's a Siemens RWB2E purchased from good old Wicks.

The wiring is exactly the same, so you should have wires in N, L, 1, 3 and 4.

1. Check that all the terminals on the back plate are done up tight.
2. Check that the switch on the back of the Sunvic is set to P

If that's doesn't cure the fault, there is either a fault in the new programmer or somewhere else in the system. Try replacing the old Siemens (hope you didn't bin it). If the problem goes away the new Siemens must be faulty - get it replaced.

But if the fault remains, the fault finding is a bit more involved. You can read how to do it in How a mid-position valve works.

 

[gibson8206]

Thanks once more for your input D_Hailsham. I remade all the connections on the back plate and Bingo all O.K.!!! Must have disturbed the screw tightness on replacement. Thanks again and

Best wishes from,

Gibson.