I have Vaillant Ecotec plus 418 heat only boiler. It’s fitted in the loft. The pump and bypass are in the downstairs airing cupboard so approx 10m flow/return combined run. I’ve just lagged all my pipes so the only uninsulated section is approx 2m in the airing cupboard. I know the factory standard overrun time is 5 minutes and I’m wondering if that now the pipes are insulated, will 5 minutes be enough to dissipate enough residual heat before shutting down? Is there a way to test this - is there a preferred temperature I need to get down to before allowing the pump to shut off?