unvented cylinder problem

Hi. I've got a Pullin Evolution 250l indirect unvented cylinder, connected to a Vaillant ecotec plus 637 system boiler. It heats from the gas boiler normally, but also has an electric immersion for emergencies. My boiler flow temp is set to 75, the HW dial on the boiler is set to 70, the stat...

Hi guys, need a little help! I've been working on a house. They had an ensuite with shower. In a separate room (dressing room) also has a bath. Their system is an unvented cylinder! Customer has removed the ensuite, I have removed the bath. The bath had 22mm pipe feeds. Here my dilemma starts...