"smoke" from chimney -- cracked boiler?

nickr

My single-pipe steam system works, but I noticed the other day this white stuff billowing from my chimney -- does this mean my boiler is cracked? It wasn't a very cold day.

STEVEusaPA

Probably.

Steamhead

Is it refilling a lot?

EBEBRATT-Ed

Are you burning oil or gas?

mattmia2

flood it and see if water leaks out

nickr

Gas fired boiler. The only time I've had to refill it is when I drain a bit out to get the sludge out.

ChrisJ

nickr said:

Gas fired boiler. The only time I've had to refill it is when I drain a bit out to get the sludge out.

Do you have an autofeeder?

nickr

ChrisJ said:

nickr said:

Gas fired boiler. The only time I've had to refill it is when I drain a bit out to get the sludge out.

Do you have an autofeeder?

Nope. Just a valve that I open to fill it up.

EBEBRATT-Ed

@nickr

Sometimes steam boilers leak above the water line and send steam up the chimney and you won't see any water on the floor.

The way to check for this is with a cold boiler add water and overfill it until the supply pipe coming out of the top of the boiler gets cold then shut the water off and let it sit for an hour or so.. Look inside and around the boiler. No water? Drain it down to normal and run it

nickr

EBEBRATT-Ed said:

@nickr

with a cold boiler add water and overfill it until the supply pipe coming out of the top of the boiler gets cold then shut the water off and let it sit for an hour or so.

If I do this and don't see any water in or around the boiler, am I in the clear?

Jamie Hall

The best test is... how much water are you adding daily/weekly/monthly?

EBEBRATT-Ed

@nickr

Between the flood test and what @Jamie Hall posted you will know

nickr

Jamie Hall said:

The best test is... how much water are you adding daily/weekly/monthly?

The strange thing is -- I don't have to add water. I have to take it away. Left to run unattended, the water line eventually rises above the recommended level so I've got to periodically drain some water to keep it at the recommended level. I don't have an automatic water feeder -- just a stupid hand valve that I open up when I need to add water. I keep it closed otherwise.

Could a too-full boiler be the cause of steam coming out of the chimney?

ethicalpaul

Your stupid hand valve must be leaking by, or if you use this boiler to heat your domestic hot water, that coil could have a leak.

A too-full boiler shouldn't affect your chimney output....but how full are we talking?

nickr

ethicalpaul said:

Your stupid hand valve must be leaking by, or if you use this boiler to heat your domestic hot water, that coil could have a leak.

A too-full boiler shouldn't affect your chimney output....but how full are we talking?

The hot water heater is separate. The cheap water valve must have a leak.

This morning, the glass water level indicator was full all the way to the top -- no air. So I've gotta assume the boiler was completely full. About a week ago I had drained some water from the boiler to set the water level to the preferred/indicated level.

EBEBRATT-Ed

What @ethicalpaul said.

SlamDunk

Which brings us back to the steam coming out of the chimney....The fresh water may have rotted through the boiler's crown. May be a pin hole now.

ethicalpaul

I'd say it was at least completely full. After the glass is full, there's no telling how much higher the water went until it starts spewing out of your radiator vents.

SlamDunk makes a great point...how long (weeks? months?) have you been draining this excess water?

nickr

ethicalpaul said:

how long (weeks? months?) have you been draining this excess water?

Just bought the house in July. Previous owner said it had to be drained every week but I thought he was talking about sludge removal.

It was only recently that I noticed the need to drain it; but then again we haven't had the heat on for very long so I wasn't poking around down there until recently.

Intplm.

@nickr
Sometimes you can take the top skin off of the boiler and spot the leak that way. Do this when the boiler is cooled. If you don't see an obvious leak you will have to flood the boiler to see if it's leaking.

nickr

Update: we flooded the boiler yesterday and didn't spot any leak. So hopefully it's not cracked.

MaxMercy

nickr said:

Update: we flooded the boiler yesterday and didn't spot any leak. So hopefully it's not cracked.

Make sure you address the water ingress. Fresh water brings oxygen which will rot the boiler.

nickr

MaxMercy said:

nickr said:

Update: we flooded the boiler yesterday and didn't spot any leak. So hopefully it's not cracked.

Make sure you address the water ingress. Fresh water brings oxygen which will rot the boiler.

The technician thinks one of the returns is clogged (it was slower to heat up than the other return) and so there may be a slow trickle of water back into the boiler from that return, causing the illusion of water ingress from a bad valve. But this guy thought that main vents are not supposed to close even when steam hits them. And the return that heated up more slowly has a new main vent on it (the old one didn't work) whereas the return that does heat up either doesn't have a main vent or has an old and likely clogged one on it.

MaxMercy

nickr said:

MaxMercy said:

nickr said:

Update: we flooded the boiler yesterday and didn't spot any leak. So hopefully it's not cracked.

Make sure you address the water ingress. Fresh water brings oxygen which will rot the boiler.

The technician thinks one of the returns is clogged (it was slower to heat up than the other return) and so there may be a slow trickle of water back into the boiler from that return, causing the illusion of water ingress from a bad valve.

Sure, but that doesn't explain why you have to continually drain the boiler since you don't have an automatic feed and you're not adding water manually.

nickr

MaxMercy said:

nickr said:

MaxMercy said:

nickr said:

Update: we flooded the boiler yesterday and didn't spot any leak. So hopefully it's not cracked.

Make sure you address the water ingress. Fresh water brings oxygen which will rot the boiler.

The technician thinks one of the returns is clogged (it was slower to heat up than the other return) and so there may be a slow trickle of water back into the boiler from that return, causing the illusion of water ingress from a bad valve.

Sure, but that doesn't explain why you have to continually drain the boiler since you don't have an automatic feed and you're not adding water manually.

True. This summer once the boiler's cold I'm going to mark the water line with tape and see if the level changes in 48 hours. If it does, time for a new valve.

ChicagoCooperator

One comment I'd like to make on the white smoke from flues - a few weeks ago we had extremely mild and humid weather, but still heating weather, and a lot of the adjacent buildings with both steam and other (I would assume all gas, I've never seem a fuel oil truck here that I can remember [Chicago]) systems were billowing/spewing white smoke - all of us couldn't have sprung leaks at the same time, so definitely do whatever tests needed to verify a leak is present.