Sudden difference in main line heating

ratherbfishing

For a few months both my mains (short /long) would heat about same rate,  meaning radiators would fill on either main fairly close in time.  Now, with nothing being changed,  the short main takes much longer to heat and the all the radiators on the long will fill before the short gets going.  What would cause this sudden change? I can still hear the the short line vent venting, so it's not clogged.

Steamhead

Dirty boiler water?

ethicalpaul

Start a call for heat and use your hands to see where the steam is traveling. See if both mains get steam to their main vents at the same time. If so you'll know you can look beyond the mains.

ChrisJ

ratherbfishing said:

For a few months both my mains (short /long) would heat about same rate,  meaning radiators would fill on either main fairly close in time.  Now, with nothing being changed,  the short main takes much longer to heat and the all the radiators on the long will fill before the short gets going.  What would cause this sudden change? I can still hear the the short line vent venting, so it's not clogged.

Are all of the radiator vents on the short line clear? Any water droplets in them? I'd start by blowing into each vent with a can of air including the main vent(s).

Anything sagged? Holding water?

Did you change any vents on the longer line?

ratherbfishing

Main vent on the long gets hot first. Didn't change anything.  

Dirty water? I did notice this about the same time the pigtail was gunked up.  Cleared that but didn't change it.  After i had the system served in December it was operating so nice.  So maybe dirty water ( it is very dirty) but how would that change it?

ethicalpaul

If there is boiler water getting to one of the mains via surging, that will kill a lot of steam there. How's your water level during firing? How's your near-boiler piping look?

ratherbfishing

Water level is good,  it's not on an auto feeder so doesn't get over filled. I suppose I could try and flush it out and see if that magically does anything.  For curiosity sake,  I switched out one of the gorton 4 s at the end up the short line with a varivent open at full.  Can really hear the air coming out but didn't speed things up on that line

ethicalpaul

I didn't mean the general water level, i meant during firing does the level drop noticeably? That would be an indication of surging.

I wonder if one of the radiators on your long line might have a large capacity vent that is stuck open and stealing the steam from the other main. Check for that.

Then if not that, I guess I'd put my hand on every radiator valve on the "cold main" to see if/when the steam gets to each one to try to find what's up.

You should be able to put a large, fast vent on one of the radiators on the "cold main" that will make that radiator heat up. If it doesn't then you know something is really up.

The important thing to remember is that the steam is going where it's easiest to go. So something is either making it real easy on the one main, or real difficult on the other main for the steam to go there. That's all there is to it.

ratherbfishing

Thanks for suggestions.  How would surging affect main line heating?

ethicalpaul

Because if boiler water is getting sent into the main piping, it can "kill" the steam

PC7060

Do you have a vent on the short main that’s not opening?

EBEBRATT-Ed

Watch the water level when it is steaming? It shouldn't bounce more than an inch or so.

ratherbfishing

PC7060 said:

Do you have a vent on the short main that’s not opening?

I don't think so,  all of the rads heat up

ChrisJ

Oil or gas?
If gas please clock your gas meter with only the boiler running.

dabrakeman

I'd double check the main vent on the slow main. If it is not open the radiators will still heat up, just much slower.

ratherbfishing

I decided to flush the boiler as recommended above. I was draining from bottom valve of sight glass and noticed it wasn't terribly dirty and running clear pretty quickly.  So i stopped draining, just cleaned the sight glass, filled about 1/2 sight glass full of water to restore water level and turned on system.  Huge difference.  The short main heats up much quicker now,  similar to previous.  It seems to have fixed it,  but I'm super confused why that worked. 

ChrisJ

ratherbfishing said:

I decided to flush the boiler as recommended above. I was draining from bottom valve of sight glass and noticed it wasn't terribly dirty and running clear pretty quickly.  So i stopped draining, just cleaned the sight glass, filled about 1/2 sight glass full of water to restore water level and turned on system.  Huge difference.  The short main heats up much quicker now,  similar to previous.  It seems to have fixed it,  but I'm super confused why that worked. 

Oily water tends to get blown up into the piping more.
This can cause big issues.

BobC

If thoseproblems come back in a few fays it means you have oil in the boiler water. That ca;;s for a couple of long skimming sessiond to float those oils out of the skim port.

Bob

SteamingatMohawk

Serviced the system in December, worked OK, now its not. Apparently there's oil in the boiler. What materials were used during the servicing?

ratherbfishing

Not sure.  Was done by a professional 

ChrisJ

ratherbfishing said:

Not sure.  Was done by a professional 

Fair enough,
Do you know roughly what they did? Piping, vents etc?

ratherbfishing

Clean the pigtail and pressure control.
Clean the probe/float type of low water cut off.
Clean the glass gauge and valves.
Clean the burner tubes.
Inspect the flue passage ways in between the boiler sections.
Perform a combustion analysis and make any adjustments if needed.
Test the boiler water PH and add chemical, baking soda or like to get pH between 7 and 10
Add rectorseal treatment 

No vent work

neilc

ratherbfishing said:

Clean the pigtail and pressure control.

not sure if it's been asked,
what's that pressure set to?
and what's the gage telling you for high pressure when boiling?
pictures?

ratherbfishing

Pressure breaks right before 1.5 psi , cuts in at about 0.5. I installed a low pressure guage to track it.  Builds pressure slowly. 

ChrisJ

ratherbfishing said:

Pressure breaks right before 1.5 psi , cuts in at about 0.5. I installed a low pressure guage to track it.  Builds pressure slowly. 

What does slowly mean?  30 minutes?

ratherbfishing

30-40 minutes last I timed it.  

BobC

Is the 30-40 minutes from a cold start? It's more helpful to know what the time is from a warm start, say 10 minutes after the boiler stops a steaming cycle.

Bob

ratherbfishing

Is a warm start any start after a full cycle when it's still hot to touch.  How would you define the interval post cycle?

ratherbfishing

Just curious,  I hear alot of "swooshing" when it's running and thy gauge water level does jump a bit (always done this). Could it be too much rectorseal?  The water in the guage isn't very pink at all though

neilc

post a picture or 2 of the boiler, floor to ceiling, so we can see attached piping,
and a close up on the controls, and sightglass,
"Whooshing" and a bouncing water line, sounds like dirty water / wet steam,
Do you have a skim port and knowledge to use it?

reggi

Maybe there's a leak in the main that may not be as obvious as this... Was this replaced or taped ? After 4 months of heating the band-aid may need changing. 
 Photos please...
You can "kick the can down the road" 
only so far...
 

ratherbfishing

@reggi taped. But doesn't seem to be leaking.  That's on the short line.  Theoretically, wouldn't a leak in the main cause that Main to heat faster as it's venting quickly?

Will get some pics soon

reggi

It's been 4 days since

@ratherbfishing said:

  Huge difference.  The short main heats up much quicker now,  similar to previous.  It seems to have fixed it,

is it still functioning correctly?

ratherbfishing

@reggi for the time being!

reggi

So the first response 2 weeks ago seems to of been correct , and one of the easiest 
items to do..less than 10 -15 minutes..but because you didn't understand or listen to the explanations of WHY you kept looking for other causes until Finally your halfhearted attempt cleared it up... for now ? 
Here's some more advice... if flushing the sight glass for a bit cleared up the issue expect it to return because you didn't get the oils off the top by draining down .. skimming would do that...  And you didn't get any sludge from the boiler's bottom because you didn't open any drain valves, you got what was suspended in the water from agitation of the boiler heating and circulation... not where it's coming from..
Skimming and flush should be on your list to do to help eliminate a repeat
My 2¢

@Steamhead said:

Dirty boiler water?

ratherbfishing said:
 So maybe dirty water ( it is very dirty) but how would that change it?

@ratherbfishing said:
I decided to flush the boiler as recommended above. I was draining from bottom valve of sight glass and noticed it wasn't terribly dirty and running clear pretty quickly. So i stopped draining,

ratherbfishing

@reggi thanks for the insight. I actually do accept the suggestion it was dirty but I inquired more to learn a bit.  I find steam interesting but very frustrating as I bought a house with a system that wasn't installed "correctly".  From this forum, I got someone very skilled to service the boiler. I'll bring up skimming for next year. I don't think I have a skim port so likely beyond my skill/time set. As always, appreciate your insight.