How to find a steam leak

Steve Garson

I have a minor steam leak near one of my radiators. I know this because of the very mild odor when the boiler is steaming. I cannot see the leak. I tried using Mega Bubble Leak Detector to see if a bubble would form, but the temperature just made it quickly evaporate. I laid a tissue over the fittings to see if they would pick up moisture and I sensed that boiled smell. I aimed a flashlight to try to see steam to no avail, but I know it is leaking.

I tried to loosen the union to re-do the joints with fresh pipe dope, but cannot budge the nut. That leaves the sawzall as the alternative, which I would like to avoid if possible. This was installed by a plumber three years ago when we redid the bathroom.

My questions:

1. Is there any bubble agent or other substance to find exactly where the leak is?

2. Assuming that I find the leak, can I use some type of leak sealer on it?

Thanks for your advice.

Steve Garson

Photo

Here is the photo. The other file was bad.

Steve

gerry gill

try

a mirror..see if it fogs up.

JimGPE_3

I was going to say

A clear glass full of ice water and, again, watch for fog.

Steve Garson

Good ideas. Now assume that I determine which joint is leaking, is there anything I can seal it with that won't require sawing off the pipe to unscrew the joints?

JimGPE_3

Oh....

For that answer you have to wait for the smart guys to weigh in.

It is, however, difficult to imagine the union is frozen already. Is that the nut you are considering going after with the power tools?

Mike T., Swampeast MO

Are you certain that the odor isn't coming from the radiator's air vent? (Forget that statment if it's a two-pipe system.)

Steve Garson

I tried using a mirror and had no luck. The nose test tells me that the leak is at the union. I can't budge it.

Any suggestions?

gerry gill

I dont know about your nose,

but if you have a steam leak you wont be able to keep your hand in close proximity to the pipe..close but not touching..

Steve Garson

Of course. The pipe is 215*. Slow leak. Low Pressure. Only occurs after the vent closes from a hot radiator, at which point the boiler typically has stopped boiling. I'm only losing about a 1/2 inch+ on the watch glass a week.

tls_9

breaking the union

Tap on the nut with a hammer.
Use two wrenches, one as a back up.
Use pull pipes on your wrenches.
Heat the nut with a small soldering torch.

tom

gerry gill

okay, if its that small

try spraying talcom powder or the like on the pipe and watching to see if a certain area gets wet..

Christian Egli

Steam is pure

It's the God intended way of heating! Now, with that in mind, steam should have no odor, again, the stuff is pure, it's sterilized, it's hygienically clean and it's hot, nose burning hot.

Is it possible that what you smell is trapped air leaking out and not steam? Is it possible this radiator is not heating properly? Is it air bound? Check its air vent.

That said, a tiny steam leak will just fizzle away and since the air just around the pipe is very hot it can absorb a lot of moisture. The same way we emit no smoke when we breathe in the summer, but we do in the cold winter. Magic.

New piping assemblies are prone to tiny leaks. With water, the holes eventually get plugged with lime build-up but since we're talking extra virgin pure steam, we may be waiting for eternity.

Unions leak for two reasons.

First, if not properly machined or nicked during assembly, the mating surfaces will not mate and will never hold tight. No amount of tightening will do. Neither will gunk. It is best to change it for a new one.

Secondly, if the pipes the union joins are not aligned to begin with, then the twisting imposed on the union will cause it to leak. Unions are not flexible as they would seem. No amount of tightening will do.

To find out what is going on, just simply unscrew the union...

I suspect the misalignment. To unscrew more easily, lift or jiggle the whole radiator in the way that will align it while unscrewing. Get help, use a crow bar, use wedges, use little muscle and don't drop or break anything. Particularly your tiles. Then before reattaching anything make sure mating surfaces are perfect and everything is aligned the way a chiropractor would do it. Maybe this job calls for higher help.

To put a crimp on the suspected leak so that you may check if it is really the cause for the boiler water loss, try wrapping the whole union and attached piping in Saran wrap, tightly, many times around, which you'll then shrink wrap with a blow dryer. It won't be cute and it won't be perfect. Maybe with some luck it will slow the leak enough to make you happy.

Steve Garson

Gerry:
Great idea!

Thanks.