Ben at Nialls finds blocked heating system. Get your system flushed before it kills your boiler. Just like a blocked artery causing a heart attack.
This is a 15mm pipe reduced to 5mm. This will cause a heat build up in the boiler until it eventually burns out all the systems parts.
Jason at Nialls. Before, during & after install of unvented hot water cylinder heated by Air Source Heat Pump. #niceonenialls