Radiator Heating Through Vent / Boiler Pressure

Kev3b

Hi all.  Thanks in advance for the responses.  This is my third heating season with steam.  I rent the second floor of a two-family home that has a one-pipe steam system powered by a Burnham low-pressure boiler. The house is owned by my fiance's aunt so I am able to change some things, but since I do not own I am limited in what can be done.  When we first moved in the system was loud and unbalanced.  I have installed adequate main venting in the basement and replaced all the radiator vents in the house.  Currently, I have two issues that I'd like some further information on. 



Issue #1 - The majority of my radiators are smaller (between 20-32 EDR).  Recently I noticed that 2 of them (Kitchen and 2nd Bedroom) have been heating up through the bottom of the radiator to the vent first.  I've tried to search for some answers, but have come up a little dry on the board.  I believe I read that when the radiator vents this way it is being vented too quickly, but I'm not 100%.  If this is the case, I'm a little concerned because all of my radiators have Vent-Rite #1 adjustable vents, which according to Gerry's Venting charts are already extremely slow vents already.  I adjusted the vents down around the house and that seems to have alleviated some of the issue, but it's an extremely slow vent rate.  They were currently set around 4-5, now they are around 2-3, on the Vent-Rite dial.  Is this the correct approach to the issue? 



Issue #2 - I also noticed when in the basement during a firing cycle that the boiler shuts off for a minute or so after around 20 minutes of running.  The boiler is slightly over-sized and the the waterline does move a little (maybe between 1/4 inch and an inch) while the boiler is steaming.  It seems the system being cut off by the pressuretrol, but not sure what the cause is.  There used to be a radiator at the front entrance that has been capped.  Could having that pipe not being heated in the system effect the overall pressure?  The boiler does not have a skim port, could oil in the water cause this?  If so, is there a way to clean it without a skim.  Space is kind of tight, as the boiler controls are installed up against a partition in the basement.  I assume this was done because the old boiler was plumbed this way, and it involved changing less when the new boiler was installed.



I realize that I may not be expressing my concerns coherently, so if anyone needs more information or has additional questions, please fire away.



System Settings:

Burnham Boiler (PIN5SNI-HE2)

Input: 140,000 BTU/HR

Output: 358 sq.ft.             

              86,000 BTU/HR

Rads                                      EDR

Kitchen                                    20

Master Bedroom                   25

Bathroom                               18

2nd Bedroom                        25

Dining Room                         21

Living Room 1                       31

Living Room 2                       51

Sunroom                                45

Attic Hall                                 34

Attic Bed                                 32

Total EDR - 302 sq.ft.

*Boiler is 18.5% over-sized



MainTotal - 1.025 cu.ft.

Vented with 3 Gorton #1s



Rads

All the radiators have Vent Rite #1 adjustable air vents. 

Jamie Hall

On issue No 2

The boiler is slightly oversized -- but no worse than most, so I wouldn't fiddle with it.  It is very likely, though, that what you are seeing after 20 minutes or so of running is that all the radiation is as hot as it's going to be, and the pressure starts to creep up.  Then the pressuretrol shuts the boiler off, exactly as it is supposed to do.

Steamhead

And on #1

some radiators just behave that way. The original American Corto units with 2" section spacing are a good example. After the vent closes the steam will rise to the top, displace the air downward and the vent will re-open. 

Kev3b

Type of rads

Thanks for the input guys. Here is a pic of the radiator.



When I turn the venting rate on the affected radiators down, they fill normally. But, like I said it's at a very low setting. I just don't want to be paying for extra fuel consumption if I don't have to. One of the rads is in the room with the t-stat.

Kev3b

Boiler Water Line

After searching a little more through the wall last night I found a post Rod had made in regards to Burnham's desired water line.  In the manual it states that the "normal water line" should be 28 5/8" off the ground (Figure 24 on Page 17).  This is about 5/8 of the way up the sight glass.  Before moving in, the water level was 1/2 way up the sight glass, about an 1"-1 1/4" lower than what is recommended in the manual. 



Since living here, I've never varied from the water level that was previously set, as I assumed it to be correct.  I guess that is what you get for assuming.  I'm going to adjust it, but could this be part of my pressure problem?

Kev3b

Thanks guys

Appreciate the responses.  My Burnham IN5 is equipped with a Hydrolevel Cycleguard CG400, and that is what is shutting down the boiler.  Good to know it's not high pressure, but it's still annoying as hell.  I understand the functionality, but there's no way that shutting down the boiler every 20 min. is good for efficiency.  Seems counterproductive to me. 



Unfortunately, I'm going to have to live with it.



Thanks for the help guys.