Programmer - gravity or pumped?

[maread]

Hi

Just replacing my 2 channel programmer as the old one has failed. New one is a Danfoss Randall FP715SI (previous Sunvic select 207 XL). On the back of the new one (and old) are 4 binary switches, one to select gravity or pumped system. We have a Potterton statesman oil-fired boiler, the central heating is a sealed pressurised system and the hot water is a gravity fed hot water cylinder. We have motorised valves which I believe allow us to have CH and HW on/off separately.

The old programmer was set to pumped so I've left the new one the same, but am now wondering if this is/was correct (I "installed" the old one but can't remember if I thought about this at the time ). Can anyone advise as to the correct setting and what the actual difference is likely to be? The previous one seemed to work without issues (that I can tell) for several years.
Thanks, Mike

 

[MTCH]

If you set to gravity then your water will always come on with the heating. If you have two separate valves then your system is most likely fully pumped.

 

[maread]

Thanks, these are the valves from the boiler.

IMG_20180627_060416937

• maread
• 27 Jun 2018

controller

So the fully pumped is just referring to how the how water gets to the HW cyclinder and that the two can be separately controlled? And the fact that the HW cylinder is gravity fed is not relevant?

Cheers
Mike

 

[MTCH]

Yes that's it.

 

[maread]

ah good, many thanks
Mike