Hello All,
I have an issue with a customers system. Gravity HW, pumped CH (pump on return). Combined feed and vent. Boiler is a Potterton Kingfisher MF, only HW control is a TRV linked to a sensor on the cylinder (tapstat?). The cylinder also has a solar coil fed by collectors on the roof.
It's intermittent, but becoming more frequent. With HW demand, after about 20 minutes the system begins to overheat, quite noisy and much air. Much noise is accompanied by hot water 'pumping' over and the bottle vent I installed on the cylinder flow hissing air. This cycle continues until the boiler locks out. I am suspecting a blockage, would I be right? The combined feed/vent enters the system on the flow quite close to the cylinder. There is a towel rad on this circuit, presumably a heat sink, and it gets very hot and noisy.
I had considered upgrading the whole system to fully pumped with full controls, but for various reasons this is not a simple solution, so more of a last resort.
Any input gratefully received.
I have an issue with a customers system. Gravity HW, pumped CH (pump on return). Combined feed and vent. Boiler is a Potterton Kingfisher MF, only HW control is a TRV linked to a sensor on the cylinder (tapstat?). The cylinder also has a solar coil fed by collectors on the roof.
It's intermittent, but becoming more frequent. With HW demand, after about 20 minutes the system begins to overheat, quite noisy and much air. Much noise is accompanied by hot water 'pumping' over and the bottle vent I installed on the cylinder flow hissing air. This cycle continues until the boiler locks out. I am suspecting a blockage, would I be right? The combined feed/vent enters the system on the flow quite close to the cylinder. There is a towel rad on this circuit, presumably a heat sink, and it gets very hot and noisy.
I had considered upgrading the whole system to fully pumped with full controls, but for various reasons this is not a simple solution, so more of a last resort.
Any input gratefully received.