Cast Iron Radiator Explodes

Ron Scheff

I have a house with hot water heat. About 5 years ago we replaced the water in one zone with antifreeze (glycol). The cast iron baseboard radiator is bout 12 years old. It popped a half moon dime size hole in the middle spraying glycol all over. We replaced that section and the remaining 14 foot section exploded leaving a 40 sq. inch hole. Anyone have any idea what would cause this?

kk_2

Interesting email address... is this really about your house? Sorry, couldn't resist asking that.

What temperature and pressure was the system running with?

Ron Scheff

Yes - It reallyis my house

The heating company said they set it at 12 PSI. The boiler normally runs at 180 degrees. The heating company is very reliable and we were able to clean up fairly quickly. I have been using this same company since 1978. The glycol that was in the system for both losses was fresh this year.

Art Pittaway

Is the glycol zone separate?

Does a heat exchanger isolate the zone you are having trouble with, or is the glycol in the entire system? If a zone is isolated with a heat exchanger, it needs a relief valve and expansion tank just like the main system. I saw a school installation where a hot water system was installed off a steam system and everyone forgot to put a relief valve on it. The expansion tank flooded and with no relief it broke two pump volutes $$$ before they called us. It takes well over 500 psi to break a volute on a B&G 1510 series. Just a thought....Art

Ron Scheff

You very well could be onto something. The glycol zone is separate and their is no relief valve or expansion tank. I am wondering if their is some new type of glycol as we did not have the issue until now when they introduced the new glycol to the system. We have had the glycol system for about 3 or 4 years. Thanks

Earthfire

pressure

this time they bleed all the air out and that left no expansion room. My guess

Aidan

Well spotted, Art.

I'm impressed! Possibly it didn't do the heat exchanger any good either.

ScottMP

cast iron BB

I had a job about five years ago that had the same thing happen.

It was a quarter sized hole and it was decided that the baseboard might have been dropped before it was installed making a weak spot that popped. Hereing your story maybe this is the way cast iron baseboard freeze. I have seen large CI rads freeze and it blows out a whole sliver.

Scott

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kevin coppinger_4

I would have to ....

agree w/ Scott.. sounds more like a freeze up...I had that happen to a customer two years back during a very windy cold snap on an cast iron rad...wind will freeze up water very fast. kpc

Aidan

Freeze up?

It's not likely to be a freeze up if there is glycol in the water. Either way, it's the same effect, water (or ice) expanding and no means of accomodating the expansion. Something has to give.