Steam Boiler Crack/Leaking Water - Can Temporarily Patch?

josepha

We have a single pipe oil-fired steam boiler that has been losing water for the past month, all the way to empty about every 7-10 days. No underground return and it has not been creating steam only for only for domestic hot water use via coil since April (no not losing steam through the system). Also, no visible leaks around the boiler. Auto water filler does not refile the boiler (I'm told because it trips when filling multiple times in a small window to avoid any floods), so I've manually been refilling the water about every 5-7 days. Presumably it will only get worse as we start creating steam next month.

Service tech advised that there is a crack above the water line on the back section (total of 4 sections I think) and wants to replace all 4. Problem is that we are already getting a new boiler in April and I would really love trying to avoid spending the money to repair now.

I plan on taking the jacket off and getting a look at the size of the crack myself, but would it be possible to cool the boiler now and try and epoxy the crack and manually refill every week if needed. I only need the boiler to limp along for this one heating season. Was also thinking to lower the pressure gauge to like 1PSI... might take a little longer to heat, but help any crack stay closed?

Any suggestions on an epoxy or sealant?
If I have to replace the sections now, will trying to replace one section be worth while or is the labor the driver of cost and might as well replace all 4?

Thanks!

Danny Scully

Well first explain to us what you mean by your getting a new boiler in April.

josepha

lol, sorry. In the process of converting to gas and installing a new boiler, but alas waiting for the new gas line proved too long and not going to make it before this heating season, so have to wait until spring to put the new one in.

Jamie Hall

Ah... if it's losing water to nearly empty, the leak can't be above the normal water line, can it? Although there may well be one there, there has to be leaking lower down. Water, despite our best efforts, does not run up hill! Unless it really is steaming, which... it should not be just for domestic hot water. The aquastat should shut it off at around 180, if not less.

So. Step one is to shut if off completely -- yes, cold showers for a bit -- and fill it to a known mark on the gauge glass and let it sit. If it holds at that level, then your leak is indeed above the water line as you tech suggests. If not... if it holds,

Step two is to overfill it at least a little way up into the header and see if it holds. If it doesn't, you do indeed have a leak above the water line.

Now. Can you fix the leak with epoxy? Or, more likely, JB Weld? A big maybe. Sometimes one can, and have it hold for a little while. Sometimes not. The key is in surface prep. For the epoxy to hold at all, the surface must be absolutely completely clean. Bare metal. No rust at all. That's not easy to do.

If you can get it to hold, it will hold for a while. Will it hold through the heating season? I'd be very doubtful, although strange things do happen. If you want to try to limp along that way, though, install a second low water cutoff with a manual reset. You don't know when it's going to go, and you don't want even a chance of dry firing the boiler.

josepha

Thanks for the insights!
"Water, despite our best efforts, does not run up hill!" ...lol

Perhaps a secondary leak below (smaller), point towards wanting to change all 4 sections. We did have a couple complaints earlier in the summer in making steam so theory is when water drops below coil in summer (and not submerged) coil doesn't get hot enough until runs long enough to create steam (not sure what the aqua stat set to now but will check). Going to watch a couple hot water heating cycles to see for sure.

I did try to fill the boiler past the (higher) summer line (above the DHW coil) when cold and for sure I could hear water draining inside the boiler immediately and did not stabilize until it reached the high water line (don't know if that was a feature or leak). Then drained slowly for a week. Funny thing is I never see any water on the floor anywhere around the boiler.

I do have both an electronic and manual low water cutoff already.

The limping along thinking was that if did drain too quickly, sections wouldn't be too difficult to source and can likely get someone out within a day to change in an emergency. Obviously less than ideal.

Thanks again!

Robert O'Brien

A boiler with a tankless coil rotted out above water line will lose water during DHW operation. Evaporation.

KC_Jones

Install the new oil boiler now, then when ready to convert to gas put a gas power burner in it.

You’d be out the cost of the burner worst case, but I’d bet you the cost of the whole job, that will be much cheaper than having an emergency in the dead of winter.

Danny Scully

Where are you located @josepha?

Fred

That water is going somewhere. If it is above the water line, the boiler water doesn't boil to heat DHW so it isn't steaming away. If it is below the water line, it should either be visible, on the floor or it is being boiled away by the burner, when it fires to heat DHW. It could be a combination of both above and below the water line but, if you look in the firebox/burner section, you should see signs of where water has dripped onto the burner.
It is not clear to me what you mean when you say "you could hear water draining inside the boiler". It has no place to drain too, especially when the boiler is cold. A leak or rotted hot water coil will cause water to be added to the boiler and raise the water level, not drain it. If you put a little effort into investigating, you will find the leak(s). I personally would not go into the start of a heating season hoping that an epoxy/Jb weld patch will hold through the entire heating season. It is not worth the risk.

retiredguy

About 15 years ago, before I retired the company was called to a job that had an H B Smith model 4500 boiler with leaking sections. No one could find the leak/leaks but the boiler continued to leak water. The leakage and water usage would only happen the boiler was "on-line" and being used. We removed all the sections, took them to the shop and pressure tested numerous sections. We raised the pressure in the sections to about 150 psig and still no leaks. One of the welders happened to be using what he called a "rose bud" acetylene torch nearby. He applied the heat from the torch to the upper part of the cast iron sections and leaks immediately appeared at the point of the flame contact. the leaks would stop as soon as the torch was taken away. This was the only time any of us ever witnessed that type of leak. It would not leak cold, it would only leak hot. If your boiler leaked only when firing the water could evaporate with the heat and no sign of water leakage could be present. One last thing, are you sure that the leak is not occurring in the wet return piping. my 2 cents

mikeg2015

KC_Jones said:

Install the new oil boiler now, then when ready to convert to gas put a gas power burner in it.



You’d be out the cost of the burner worst case, but I’d bet you the cost of the whole job, that will be much cheaper than having an emergency in the dead of winter.

I agree with this. Just out the cost of a burner and labor to install it. Might.... might get a company to give you a small credit for hte used burner.

Still better than the safety risk of a severe leak like this.

pecmsg

josepha said:

lol, sorry. In the process of converting to gas and installing a new boiler, but alas waiting for the new gas line proved too long and not going to make it before this heating season, so have to wait until spring to put the new one in.

There are issues with getting new gas service in several areas. Don't wait replace the boiler before the winter!

SuperJ

why not install a propane boiler, since the propane to NG conversion is pretty straightforward. You could get a couple temporary propane tanks to get you thru the winter. Seems like it would be cheaper than going fuel oil to NG. And if NG never comes, it's better to be stuck on propane (in most areas).

Intplm.

@josepha One thing you can try as a temporary fix. And I do mean temporary ! Is to use a type of boiler seal liquid. This type of product can buy you some time before installing the new boiler. Look for "Boiler Seal".

But ! If you can get the new boiler in now, do it.