Tempus 7 - Heating & Water not working independently

[russbow]

Hi, i wonder if anyone can assist?

I have a Suprima 60 boiler which used to have a potterton EP2002 programmer. I replaced the programmer for a Tempus 7 as i wanted to control the HW & CH seperatly and was used to this programmer from a previous house.

The system also has a digital room stat and a cylinder stat. I replaced the room stat some time earlier with no impact (except a consistant temperature ).

The wiring guide for the tempus advised on the wiring change required when moving from the EP back plate and it was dead easy to do. however it doesn't work quite as expected.

The HW works independantly and doesn't need the CH on, however when the CH comes on the HW also comes on and cannot be switched off until the CH is switched off. This is the same whether done by the clock or using the boost button.

Could this be because the old EP back plate had no wires to the connections for either the CH OFF or the HW OFF, only N, L, HW ON & CH ON? Or, is it likley to be a faulty programmer

Any help would be appreciated. RussBow...

 

[Softus]

...when the CH comes on the HW also comes on and cannot be switched off until the CH is switched off.

The rest of your post is very clearly put, but this sentence doesn't convey very much.

By "comes on", do you mean that a zone valve operates, or that a light on the programmer is lit, or what?

Also, on the Tempus 7, there's a jumper that determines whether the programmer operates a partially or fully pumped installation - have you set that jumper correctly?

 

[russbow]

By "comes on", do you mean that a zone valve operates, or that a light on the programmer is lit, or what?

Sorry , i mean that the lights on the programmer for the operation of the CH & HW come on and both the rads and hot water are heated.

i'm sure i set the jumper correctly as per the instructions, but i'll check.

Thanks

 

[Softus]

OK. So do you have either a three-port or two two-port zone valves?

If not, then the hot water in the cylinder is bound to heat up when you have the central heating on.

 

[russbow]

Sorted now thanks, a simple issue of the PUmp or gravity switch. I had it on gravity as it has a loft tank but it works fine when set to pump.

My mistake.

Thanks for your help