The V8 Owners Forum -

I managed to get a load of crud out of my radiator with a good blast of water (narrow pipe off a mains pressure hose).

But the bottom 2 or 3 rows in the core are still blocked.

Any tricks to getting these clear?

A fairly safe de-scaler is citric acid. Plug the rad outlets bar one, and fill it with the mixture boiled in a kettle. One tablespoon per litre. If you can keep the rad hot with say a fan heater, it will work quicker. But some can be so blocked only rodding it through will work.

DaveEFI wrote: ↑

Mon Jul 26, 2021 10:40 pm

A fairly safe de-scaler is citric acid. Plug the rad outlets bar one, and fill it with the mixture boiled in a kettle. One tablespoon per litre. If you can keep the rad hot with say a fan heater, it will work quicker. But some can be so blocked only rodding it through will work.

I have got some proper descaler for kettles/coffee machine ect. but I wasn't sure if what ends up in radiators was limescale.

The stuff I got out so far looks more like sand! It seemed to have packed together tight enough not to move when just shaking the rad about with water in. It only budged when I got a high pressure jet of water in there.

I saw a video where a guy just used central heating flush fluid and a big drainage pump to power flush his radiator.

'Sand' sounds like someone has used a leak sealer.

Yep, most gritty or small particle type residue is likely some sort of leak stop type product.

This seemed to work!