A few signs your boiler may be in need of repair include: Gurgling and whistling sounds; could be air in the system, system running inefficiently, not enough water or lack of maintenance If your boiler looks like it’s been burnt; this could be either a blocked heating system, blocked vent or blocked chimney Your system not reaching the temperature that you’ve set on the thermostat Water on the floor near your boiler; this could indicate a faulty safety system, faulty fresh water feed or the temperature on your system is too