Pinhole leaks in radiators - a domino effect?

psicic

Hi, bit of a weird one here. The gas-fired central heating in my parent's house has developed a bad habit of radiators developing pinhole leaks. It seems to be snowballing as a problem. I understand that pinholes are usually the result of corrosion and wearing exaserbated by metal fragments in the system.

My parents had 4 out of seven radiators in their house replaced 4 years ago - 1 of the old radiators developed a pinhole leak about a year and a half ago(we replaced this), then three months ago, one of the 'new' radiators went(which we also replaced), then a month ago another of the 'new' radiators went and now the radiator we put in a year and a half ago has gone. So we basically have two radiators out of commission now and are worried there may be more problems ahead!

We're slightly confused about the cause. We added a rust inhibitor three months ago, and suspect this may have something to do with things - we're in a softwater area in Dublin, so water acidity shouldn't be a big issue. And we haven't done any major pipe-cutting on the system, so we don't know where any metal shards may have entered the system.

I figure that we should drain the system, then go to each radiator one-by-one, disconnect it and 'flush it out' using a hose pipe connected to the mains. My Dad used micro-bore throughout the system (stepped up to 1/2" at each radiator), so that's why I figure we need to do each radiator one-by-one. Then I'd try and repair the pinholes in the radiators with self-tapping screws and plumbers tape if possible rather than spend another couple of hundred on radiators.

But I'm wondering if anyone else has had a similar experience? Would flushing out the radiators the way I described achieve anything worthwhile, or is there a better solution people have used? (To be honest, it's a plan I've just pulled out of thin air after giving the issue a bit of thought, so I'm happy to be set straight if it won't achieve anything.)

Outkast_IRE

Is it an open or sealed system ,if its open you should tie up the ballcock for a week in the expansion tank and keep an eye on the water level see does it drop much .

If its a sealed system does he need to top up the pressure often ?

Rads will rust a hell of a lot quicker if theres a leak somewhere and freshwater is constantly introduced.

Another thing to check for if the system is an open one with an expansion tank in attic , when the system is running is there any water coming up the vent or cold feed ?

psicic

Thanks. Just found two more of the radiators have gone. :eek: Must have happened sometime in the last two or three weeks.

It's an open system.

We'll tie up the ballcock and see what happens. (I can't really do any work on the system for a few weeks as I have an injured hand, so this is probably the best thing to do for now anyways).

Outkast_IRE

psicic wrote: »

Thanks.

It's an open system.

We'll tie up the ballcock and see what happens.

Just found two more of the radiators have gone. :eek:

Just check it every day for the next few days , if theres any major drop then you know its a leak

psicic

Huh.... I went to tie up the ballcock and found the expansion tank filled with quite hot water!

I'll check tomorrow evening whether it's coming through the vent or back up the feed pipe.

I have my fingers crossed it'll end up being the circulation pump is turned up too high.