Why boiler
pressure keeps dropping

The correct pressure on a boiler is, when cold, between 1 and 1.5 bar. If it keeps dropping, water is being lost somewhere. Here's where to look.

A leak on the system

Most often, a slow drop means a small leak somewhere: a connection, a radiator, a pipe. Sometimes it's visible, other times hidden in the wall and needs tracking down.

The expansion vessel

If the pressure swings a lot between hot and cold, it may be a tired expansion vessel. It's a part that's checked and recharged at the service, without big costs.

Don't keep topping up the water. It's like pouring fuel into a leaking tank.

Why not to ignore the problem

A boiler left without water can be seriously damaged. If the pressure drops often, stop topping up endlessly and call a plumber, so we find the cause. See how I find leaks.