Glow-worm Low Water Pressure Switches

These tend to be fitted to the older standard efficiency Glow-worm boilers and monitor the pressure of the water present within the boiler, they are designed to switch the boiler off if the pressure in the boiler falls below a pre-set pressure normally 0.5 bar or 0.25 bar of pressure. This prevents the boiler form running at low pressures which prevents damage to the boiler.