Radiators Keep Needing Bleeding? Here's the Real Reason

Bleeding a radiator now and then is normal. But if the same radiators fill with air week after week, no matter how often you bleed them, something more is going on than the odd air pocket.

Where the gas is coming from

When you constantly get air back, it is often not air at all but gas being produced inside the system. As the water corrodes the steel in your radiators, the chemical reaction releases hydrogen gas. That gas collects at the top of radiators exactly like air does, so you bleed it out, only for more to form. The corrosion is the engine that keeps producing it.

Why it should not be ignored

Constant bleeding is a symptom of active corrosion, and corrosion is what creates the sludge that blocks radiators, causes cold spots and strains your boiler. So while bleeding solves the immediate annoyance, the underlying process is quietly damaging your whole system. It also means you are regularly letting water out, which can affect your boiler pressure. If yours drops often, see our guide on boiler pressure that keeps dropping.

How to actually stop it

The way to break the cycle is to stop the corrosion. A power flush clears out the existing sludge and, crucially, refills the system with a corrosion inhibitor, a chemical that stops the reaction producing gas in the first place. Once the inhibitor is protecting the system, the constant gas build up stops and the endless bleeding comes to an end.

We carry out power flushing across Sunderland, Durham and the North East, with fixed pricing from £495 including VAT. Get a free quote or call 0191 540 2051 and we will get your system properly protected.