Boiler Guides

Your boiler’s condensate pipe is the plastic pipe that carries waste water from your boiler to a drain. Every modern condensing boiler has one. If it’s leaking, the cause is…

A dripping boiler overflow pipe usually means your boiler pressure is too high, the expansion vessel has lost its charge, or the pressure relief valve is worn and no longer…

If your heating is not working but the hot water is, check the room thermostat, the heating timer and the boiler pressure first. Those three cause a lot of cold…

If your heating works but there’s no hot water, the cause depends on your boiler type. On a combi, it’s usually a stuck diverter valve or a faulty flow sensor.…

If your boiler is not firing up, the most likely reasons are no gas getting to it, low water pressure, a frozen condensate pipe in cold weather, or the boiler…

Your boiler pressure should be between 1 and 1.5 bar when the heating is off, rising to roughly 1.5 to 2 bar while the heating is running. Under 1 bar…

To repressurise a boiler, turn it off and let it cool, open the filling loop slowly until the gauge reads between 1 and 1.5 bar, then close it again and…

A boiler that keeps losing pressure nearly always has one of four problems: water escaping through a small leak, air let out when radiators were bled, a pressure relief valve…

D1 on a Worcester Bosch is a return sensor fault: the boiler can’t get a sensible reading from the sensor that measures water coming back from your heating system. We’re…

C6 on a Worcester Bosch is a fan fault: the fan that pulls air through the boiler and pushes exhaust gases out isn’t running at the speed the boiler expects,…

E9 on a Worcester Bosch means the water in the boiler got hotter than it should, so a safety limiter tripped and shut the boiler down. We’re Clever Energy Boilers:…

An A1 on your Worcester Bosch is a pump and water fault: the boiler has detected that the pump is stuck, running dry or working against air, and often that…