I would always use quality full bore ISOs on gravity supplies. Flexi tap connectors can be narrower bore than 15mm copper pipe which can affect flow. Also modern taps with ceramic valves can be more restrictive than old fashioned washer valved taps. Restrictive ISOs can be a third restriction that can all possibly add up to disappointing flow - especially hot.
If your head of water is near the minimum required by the new taps, then flexis and cheap restrictive ISOs may have a big impact on flow.
If your head of water is near the minimum required by the new taps, then flexis and cheap restrictive ISOs may have a big impact on flow.
