Oil Smell from Air Vent on Radiators

ColdNights

Help! What is that oil smell from our steam radiators and how do we get rid of it??

We recently had a residential gas-fired steam boiler installed in our home with some new piping around it but all of the house piping and all of the radiators are the same. The radiators have a weird motor oil smell coming from them when the air exits the vents. It's like a steamy auto shop. The smell is pretty bad, and we aren't sure what it is.

We had the boiler skimmed and blown down a week after installation (today), but the smell persists from the radiators. The installation company has never heard of or experienced this before.

Any hypotheses and ideally remedies?

Thank you!

Fred

None of the installers ever heard of or experienced the smell from radiator vents. If it smells like oil, it probably is. A new boiler and new piping may have to be skimmed several times to get all of the oils off of the surface of the boiler water. If it was skimmed today (and skimmed properly) wait a couple days and skim it again and maybe again after that. Make sure you are skimming it properly, from a skim port above the boiler water line and very slowly. Draining the boiler won't remove the oils. They will just cling to the sides of the boiler as the water drains.

Big Ed_4

Agree .

ColdNights

Thanks! What is your recommended pace for doing the skim? Both in terms of flow rate and overall time to do it for?

Fred

ColdNights said:

Thanks! What is your recommended pace for doing the skim? Both in terms of flow rate and overall time to do it for?

Water Flow should not be any larger than the diameter of a pencil and at least five or six 5 gallon buckets. If you have a nearby floor drain, I like to set the flow rate and then connect a garden hose and run it over to the floor drain and let it drain for an hour or two.
Start the boiler and get the water hot but not boiling/steaming and shut the power off and start the skim.

ethicalpaul

Did they run the boiler with TSP or similar in it for awhile after installation? I think most manufacturers recommend that step also

Dave T_2

@Fred is right on. I have also poured vinagar in and steamed boilers to clean heavy oil and skimmed with success (smells like salad for a while)

nicholas bonham-carter

I wouldn’t use vinegar, but just the washing soda, recommended by Peerless. Acid is bad for cast iron.—NBC

New England SteamWorks

Sure sign you need skimming.

ColdNights

OK team - a follow up problem I am hoping you can help solve.

Skimming has helped get a lot of the oil out of the system, but the smell persists (although it seems not as strong).

I tried cold skimming first and found that less oil came out of the system, so moved to "warm" skimming where I'd fire up the boiler until right before it steams, then shut it off to skim. This produced the best results for getting oil out.

However, I think mostly the new water is coming to the top vs. pushing up the older oily water. I can tell this because the water I skim becomes cooler whereas if I blow down to finish there is a lot more warm/hot water in there.

See attached photo for boiler set up, and excuse my less technical descriptions of the various components.




Questions for you all:
1. What is the reason for the cold water coming to the top even though the entry point is near the bottom?
2. Should I be doing anything differently to get the oils out more effectively?

neilc

that's not a terribly large boiler, it doesn't hold that much water,
what does the manual suggest it holds?
and how many 5 gallon buckets are you filling when the water cools off?

skimming is a repeated hours long process, and could take any where to a couple, to several skims, on multiple days / possibly weeks apart,
since you have the smell throughout the system, you will need to continue diluting the system from each next skim,

skim, then running the boiler for heat will then steam clean the system, and bring more oils back to the boiler,
another thing,
when done skimming, drain the whole thing from your return blowdown, this will pull some dirty oily water from that wet return which is being held back by the Hartford loop,
refill and fire up,

how many skims have you done, and for how long each?

ethicalpaul

Did you run a couple cycles with tsp? I feel it breaks up and encapsulates the oily gunk, freeing it up to let it skim out.

if you run it with tsp and a higher water level, the boiling splashing water will wash the higher areas in the boiler.

Neild5

Can you move to the right side of the boiler showing the return and Hartford Loop?

mattmia2

If it has oil on top of the water it could have been throwing water and oil up in to the system and it will take several skimmings between running it to bring that back to the boiler where you can remove it.

SlamDunk

One thing I did when I experienced the same smell after skimming was to vent the main that feeds the radiators a lot faster than the radiator. The smell will stay in basement instead of living quarters.

ColdNights

Thanks all. I'll try to answer all of the questions as whole here:

The boiler was not cleaned with any chemical cleaners at the time of install. It was supposedly skimmed at install, about a week afterward, and then 4x in the past 7 days (six weeks after install). Each skim has been 2-5 hours, and I follow the guidance of having the water be no larger than a lead pencil. All skimmings are followed by a few blow downs. This is exactly what is recommended by the manufacturer (Carrier). The manual also says don't use chemical cleaners in it.





At the end of today's skim (#6 total), the water at the top was clear but the return was pretty murky. It seems like there is a lot of built up oils/lubricants in the return. See attached photos.

1. Is it possible the oils are stuck as sludge in the bottom of the Hartford Loop? During the 2nd blow down (one week post install) sludge came out to start.

2. Could the pipe dope actually be creating the problem? I have heard both that it is fine to use for residential steam and that it breaks down causing oily gunk.

Thanks again - this forum is the only thing getting me through this as there aren't too many pros in Colorado!

ethicalpaul

I guess tsp is a chemical (what isn’t?) but well, it should help break down any oils I would think.

Don't blame the pipe dope...that way lies madness

JUGHNE

If you are using the full size 2 1/2" side port for skimming, most of the water coming out is from that closest section.
If you look inside the boiler at that point you may see reduced push nipples connecting the upper sections.
So closest section will drain first.

IMO, you should add an 1 1/4 reducer and pipe nipple where the plug is. This will raise the water level up over all the section tops and float more oils out from the entire boiler.
{A rising tide floats all oils}

Where at in CO?

neilc

water has cleared up a bit, eh?

are those, in slab, wet returns, behind the small piece of ciderblock?
or is this all dry return?
are you draining the small wet Hartford loop / dry return completely(that hose bib on the right)?
that would hold back oils also?

ColdNights

The water from skimming has cleared, but not from the blow down and draining the hose bib. Both are pretty oily (dark oil picture above), which makes me think the bottom of the Hartford Loop is filled with gunk.

Where are all of these oils hiding?!

ColdNights

Is "washing soda" an ok alternative to TSP? And what exactly is that?

Also we're in the Denver area if anyone knows pros out here.

EdTheHeaterMan

TSP TriSodium Phosphate is available at a paint store, hardware store, and I just asked Alexa... Yep, it is available on Amazon.com

Here is an informative video published by Weil McLain in the 1980s as part of an educational program. TSP is mentioned around 19:30 mark in the video
https://www.youtube.com/watch?v=aIQSoBysQq0

SlamDunk

Show us a pic of your main vents.

ColdNights

@slamdunk - what does the main vent look like? And where would they be? I don't see anything down here in the utility room, but also nothing closer to the radiators.

JUGHNE

They may be at the end of the steam main where the pipe turns around and heads back to the boiler.
Can you back up and show us more of the boiler piping, floor to ceiling, from other angles?

SlamDunk

What @JUGHNE said. Follow the larger steam pipes in basement as they move away from the boiler. At some point, it (they) will reside on a nipple above the pipe, sometimes between floor joists.

If they are properly sized and functional, steam will push the majority of the smelly air out of these vents, which will close when steam reaches them. Then steam will head to radiators.

I think the rule of thumb is to vent your mains fast and your radiators slowly.

SlamDunk

They can look like this



or this:

ColdNights

OK so I found the main vents. They are at the end of the return line before syncing into the Hartford loop. See below:

ColdNights

The problem persists though - skimming produces a fairly clear output with barely any oils, but there is dark, opaque water coming out of the return (where I do the blow down).



Will the TSP clean resolve this? Or are there alternatives?

MilanD

You can def try to flush that pipe where your short wet return is. Remove the air vent above, shove a hose in there and open the flush valve at the bottom. If you feel adventurous, mix some TSP and pour it in there first, then fill with water and then open the flush valve... Some water will back out of the boiler until it hits the level of the Hartford loop, which is ok and will flush that pipe section too...

MilanD

Btw, you won't get completely clean clean water in there as it will always pick up rust and sludge from old pipes and rads. Is your sight glass water relatively clean? If that's clean, you're fine. Lastly, you can always blow down some water from the bottom of the boiler if that is bothering you. 5-10 seconds and you are done. People with float controls need to do a weekly blow-down, so you doing it won't hurt the boiler too much (a bit excess make up water). 

WMno57

Steam noob here. I know next to nothing about steam. Are those drip legs on the Hartford Loop a bad idea?

I may be a DIYer, but it appears to me the "Pro's" who installed your boiler didn't have a pipe threader. I count SIX unneeded couplers and at least one extra union because they choose to play erector set with a bunch of standard size nipples. 15 unnecessary leak and failure points. Not counting the Hartford Loop drip legs.

ColdNights

WMno57 said:

Steam noob here. I know next to nothing about steam. Are those drip legs on the Hartford Loop a bad idea?

My incredibly novice theory based on days of skimming and blowing down, and seeing where dirty water is, is that there is a lot of sludge (thick, oily gook) stuck in the drip legs, which is making it take forever to clean the system. The oils slowly come off the top of them and into the boiler, which is causing the smell.

In my brain I just want to vacuum them (metaphorically speaking)

neilc

so why don't you uncap the 2 of them, and repipe, to valves, that spill at the pit,
just like the PVC to the left,
more flushes, more better,