Should I replace boiler, or just leaky nipple.

DavidK_2

I've got a 30 year old single pipe steam heating system. Boiler is a Dunkirk "blue circle". I like it just fine. Except when they remodeled the house, they took out some radiators, but then did not add a radiator to the addition, we use electric in that room. By my calculations the 150k btu boiler is a little big for existing radiators, but would be about right if we could manage to get steam heat in the addition. Which is probably possible, but not easy. House is from 1938, boiler was replaced just before I bought house.

Since then, we've added a minisplit system to the house, mostly for cooling in the summer, but in winter we use it to heat the addition. Has worked fine so far. I'm sure it is more efficient than the radiant electric heat they installed in that room. And it might be even more efficient than steam, as long as it was not really cold outside.

Anyway, last winter a nipple in the water return pipes started leaking. It appears is has rusted out from the inside. I patched it with epoxy putty. For now all is good, but I suspect it would be a good idea to at least replace that nipple. So then I started thinking, maybe if I'm going to have to replace near boiler piping, I should consider getting the boiler replaced at the same time.

Then I started getting estimates. Replacing the nipple will be 2-3 hours labor, baring unforeseen issues, plus a few dollars in parts. About what I expected. Replacing the boiler was about twice what I expected. But now days everything seems to cost more than I expect.

The newer boilers have auto fill, and a vent damper. Things I'm not sure I want. I like single pipe steam since it takes essentially no electricity to run. I can run it for several days on a car battery if needed. I don't mind going down once in a while and making sure the old girl has water. I'm sure vent dampers increase efficiency, but how much, and what happens if they fail?

So, what would you do in my shoes. replace the boiler, or just the leaking pipes?
Thanks

Jamie Hall

For me that would be a complete no-brainer. Replace the leaking pipes. Even if you find more of them. That boiler could well have years of life in it.

EBEBRATT-Ed

I agree with @Jamie Hall

Snowmelt

I agree fix the leak

JUGHNE

Even if you changed the boiler you would have to fix the leak.
Do you have wet returns and do you have to add water very often?

What is your procedure to power the gas valve with 12 VDC battery...inverter to 120 VAC?

ethicalpaul

I agree with just fixing the leak, but on the other topic, don't fear dampers, they are good. You can lock them open if you are in an extended "running from a battery" situation.

Now to give us something nice, send some pictures of your near boiler piping from about 6-10 feet away, we love to see it

DavidK_2

I currently have no leak. But I'm not sure if an epoxy patch is a long term solution. Maybe it is. Epoxy is cheap. And strong. But I think a new pipe is likely better.
Assuming no leak I check about once a month for water, or when I'm down there. I'm estimating I add a cup or so each time, so, maybe a quart a year. Furnace holds about 1.5 buckets. Each bucket it about 3 gallons. I flush and fill in the fall, then fire her up. I'm just guessing with water use. It was not a problem in the past.

The leak is in a wet return. I only noticed it because the low water shutoff did its job. While I was waiting to do patch, I checked daily, I topped up once in week. It is a slow leak, now no leak, but who knows what might happen.
I currently use a battery, then an inverter to AC, then a transformer converts that to 18V. Not very efficient. But it works. I've been told I could probably run my furnace on 12v DC but have not tried it.

I've heard 3 good reasons to replace the boiler at the same time.
1) if pipes have failed, the furnace might not last much longer.
2) The boiler is probably filled with sludge, so even if it does not need to be replaced, you might gain efficiency.
3) when the boiler fails, and it will, you'll have to buy new pipes again

DavidK_2

I used to be able to post pictures, but, can't seem to do it now. I don't see an add pictures button.

DavidK_2

I fear dampers. That is why I have a CO detector down there. I assume they are safe. But they scare me. Do they fail open or closed? Likely my fear is unfounded.

Jamie Hall

Sorry, but in my humble opinion, @DavidK_2 , none of your three "good reasons" is all that good.

1. Wet returns are notorious for leaking. Pinholes from the inside. While it is quite true that if you have one leak in a length of pipe you are likely to have others -- which is why one should replace the entire length of pipe all at once -- it is not true that a leak in a wet return has any bearing on problems with a boiler.

2. There may well be some sludge in the boiler. Wouldn't be a bit surprised. That's why the boiler drain valve is there. Open it up, flush it out, close it and be happy.

3. That may be valid -- but not a reason to replace an otherwise good boiler. Yes, if it failed next fall, you'd be out the cost of that lovely new pipe. Maybe. Maybe not. But as you have discovered, the cost of a new length of pipe is considerably less than the cost of a new boiler...

As to adding pictures. If, when you writing a comment, you look at the set of icons above the editing area, you will see a group of them with down arrows. Hover over the one farthest to the right (just to the left of the three alignment icons on the far right) and it will say "Attach image". Click on that, and then select the image file from your computer.

dopey27177

The leak you have in the wet return is beginning of cancer in the wet return system.

Be smart! epoxy is a temporary repair and only should be used during the heating season to get you through the repair till a more permanent can be made.

it is summer now drain the boiler to remove all grit and grime from the boiler and the wet return system.

Replace the entire wet return piping. the pipe replacement can be done with type L tubing.

As per redoing the boiler piping, if you did not have a problem with banging or condensate water being pushed up into the steam piping system do not do anything with that because when you need a new boiler all that piping will changed with the new boiler.

When the boiler is replaced make sure you you have the installer pipe the boiler by the manufacturers instructions.

Jake

neilc

Fixing the nipple, NOT with epoxy, but by replacing and minor pipe work makes sense,
IF,
the rest of the boiler is good,
no better time than now to flood the boiler, up to the header, and make sure there are no other section leaks above the normal water line.
if there are other boiler leaks, then you can rightsize a replacement

ethicalpaul

Yeah, by "fix the leak" I meant with a new pipe, not epoxy

The damper has a position sensor in it, so the boiler won't fire unless the damper is open. It's quite safe and there must be millions of them out there.

I probably wouldn't replace the whole wet return system, but instead, I would probe it and inspect it to see if there are other areas close to failure. The nipple on the return where it enters the boiler is typically the very first place a failure occurs and in my experience, anyway, many of the other pipes can be in fine shape even though this one nipple rots out (I think my hartford loop was about to go so I replaced it also).

DavidK_2

Good idea to flood the boiler to see if thre are other existing leaks.