Pin hole leak in radiator

Hello , I have just discovered a pin hole leak at the bottom of a radiator, It is not coming from the valve but from the bottom of the rad itself, The water is a rusty colour, I am just about to head off on holidays and could do without this happening now, Is it do-able to just turn it off and flush it , If so how, Thanks for any info.

The problem with one rad having rusted through ( which it sounds like) is that others may follow suit soon.
If you don' t a have time to get a plumber in before you head off, then for complete peace of mind while you' re away I would drain down the system and obvioulsy leave the heating off.

Failing that, at the very least, turn off both valves on every rad, so if one springs a leak while you' re away it will be contained to the contents of that rad only.

Pinholes in rads are usually an indication of another issue, such as with open vented systems incorrect plumbing of the cold feed in relation to the pump, a leak that is continuously being topped up by the f & e tank or an automatic filling valve in sealed systems.

It is generally caused by two things, oxidisation from continuous fresh oxygen being introduced into the system or electrolysis from the many different metals within the system.

Are you having to bleed rads frequently?

Some simple tests can be done to see what is happening. For electrolysis, when venting a rad, hold a carbon monoxide alarm at the rad vent. If it alarms, it is hydrogen, which false alarms a CO cell. A powerflush will be required & a decent inhibitor added which will prevent electrolysis from re-occurring.
If not, then it is air & further investigations are required. Either way, a powerflush should be done & an inhibitor added.