Convert to Y plan

Hi I'm converting a heat only boil to a y plan as only doing the heating, hit water is from the Aga, question is what do I do with the Aga hw connections, take out? Loop? Cap? Regards

The Aga needs a flow of water, on the narrow boat we had to use two 12 volt pumps with auto change over to ensure if one failed the other would always ensure a flow of water, it was a pain and likely it would have been better to remove the boiler altogether. No water flow = big bang.

In a house normal method is to use thermo syphon so not relying on pumps, unlike gas or oil, loss of power does not auto cause flame out, so one can't rely on not having a mains failure, even with the narrow boat where power was from batteries not sure if it would pass a RCD check.

I know you can't use a S plan with a back boiler, not sure about Y plan, normal was a C plan without a motorised valve, the motorised valve was only added to latter versions of C plan.