Future-proofing an unvented cylinder for a future heat pump
I currently have a vented hot water system with a loft storage tank and a heat-only gas boiler, but as part of my renovation I want to upgrade to an unvented cylinder. Longer term, I’d like to switch to an air-source heat pump, so I’m considering buying a heat-pump-compatible unvented cylinder with a larger coil now and simply running it from my gas boiler in the meantime. My understanding is that the larger coil is needed for the lower flow temperatures of a heat pump, but I’m unsure whether there are any disadvantages or problems with using one with a gas boiler initially. Is this a sensible way to future-proof the system, or would I be better off buying a standard unvented cylinder now and replacing it when I eventually install the heat pump?