Steam Boiler Help

Bomba

Hi all,

I bought a new house (first time homeowner) and it came with a Utica steam boiler (PEG150CDE). I was wondering if anyone can help me and tell me if my steam boiler is running the way it should. The house is around 1400 sqft, (2 floors, 9 radiators, all vents are working) and the boiler input is 150,000 btu. On the sticker on the boiler, the output is left empty, the D.O.E heating capacity is 120,000, the steam is 375 sqft, and the steam BTU/HR is 90,000.

My Cut-in is set between .5 - 1, and my Diff is set to 1. The heat was off all day so when I got home from work it was 61 degrees in the house. I set the thermostat to 70 and I watched the boiler. The run times are as follows:

Run: 50:39
Off: 1:09
Run: 5:08
Off: 1:03
Run: 3:54
Off: 1:12
Run: 3:20
....and then it continues in around 1 minute off, 3 min run times until 70 degrees hit.

The only things I notice when the boiler is running is that:

During start up I can hear the water being to boil, but while its running the boil sounds seem to lessen. While its running the water in the sight glass surges, and although I tried to clean the boiler and flush many times it still surges a lot (might skim the boiler to remove the stuff floating on top).

Thanks everyone, any input would be greatly appreciated!

Ryan

KC_Jones

Coming back from a 9 degree set back I would expect that. You are bouncing off the pressure limit because it's running for so long trying to do that recovery.

By the way 9 degrees is a massive setback, why are you doing that?

Bomba

That was an error; I work 24 hour shifts and my wife turned the heat off before she left for work in the morning.

My main concern was; is the boiler supposed to turn off (no flame) and then turn back on that much? And if so, is it supposed to only stay off for a minute each time? Im assuming this is happening because the pressure is reaching the cut-in? My pressure gauge never reaches any numbers, but I'm assuming this is because the gauge is 0-30psi, I need to change it to a 0-5.

I forgot to mention, this is a 1 pipe system.

KC_Jones

Steam system pressure is a function of boiler size to radiator size and amount of venting. If the boiler is oversized and the venting is poor it will bounce off the pressure limit.

When you recover from big setbacks the radiators will fill all vents will close and you are at the mercy of the boiler size compared to radiation this is essentially worse case. That is what you were seeing and that's what I would expect. IMHO under normal circumstance and with proper sizing you shouldn't ever hit pressure limit. It's a safety not an operating control.

Bomba

KC_Jones said:

Steam system pressure is a function of boiler size to radiator size and amount of venting. If the boiler is oversized and the venting is poor it will bounce off the pressure limit.



When you recover from big setbacks the radiators will fill all vents will close and you are at the mercy of the boiler size compared to radiation this is essentially worse case. That is what you were seeing and that's what I would expect. IMHO under normal circumstance and with proper sizing you shouldn't ever hit pressure limit. It's a safety not an operating control.

Thank you for your opinion. Is there anything you think I should do/can do to help this problem?

Its possible that I don't have a main vent. The only vent that I see is Tee'd off the water fill (the pipe bringing fresh water into the boiler). I can't see this being correct.

Whether or not the boiler is oversized is something I cant change, at least not until I plan on replacing this one. If all my vents are working on my radiators, with the absence of a main vent, maybe thats why I am having constant starting and stopping.

Jamie Hall

If it's running 3 minutes on, 1 minute off at the end of a nice long run, that's not bad. Many boilers are -- or were -- sized with a 33% additional factor over the measured load -- the radiators -- to allow for initial heating of the system -- and that is just about what you are seeing.

A 0 to 3 or 0 to 5 pressure gauge -- in addition to the 0 to 30 which code usually requires -- would be interesting, but not really necessary. What pressure do you have it set at to turn off?

Bomba

Jamie Hall said:

If it's running 3 minutes on, 1 minute off at the end of a nice long run, that's not bad. Many boilers are -- or were -- sized with a 33% additional factor over the measured load -- the radiators -- to allow for initial heating of the system -- and that is just about what you are seeing.

A 0 to 3 or 0 to 5 pressure gauge -- in addition to the 0 to 30 which code usually requires -- would be interesting, but not really necessary. What pressure do you have it set at to turn off?

If thats the cut-in, plus the DIFF; then it should be around 1.5-2.

KC_Jones

If you want to discuss venting, first step is post pictures of what you have.

Second step would be to measure the length and diameter of the mains. With that we could recommend amount of venting and let you know how inadequate what you have is. I haven't seen anyone post yet that had proper venting, except for people who have been here first, or had a contractor from here first.

Bomba

KC_Jones said:

If you want to discuss venting, first step is post pictures of what you have.



Second step would be to measure the length and diameter of the mains. With that we could recommend amount of venting and let you know how inadequate what you have is. I haven't seen anyone post yet that had proper venting, except for people who have been here first, or had a contractor from here first.

Im unable to edit these pictures but I'm sure you can see what I have going on. I would like to add a skimmer valve with a T into a vent on the left side of the boiler where the 2 1/2 inch cap is located.

Which vent would you recommend I use?

Fred

Based on the water bouncing and surging, like you indicate, I suspect some of that on and off activity is because the boiler needs to be skimmed. When the water level drops enough, the Low water cut off will shut the boiler down, then the water rushes back into the boiler and the heat cycle resumes. Draining the boiler will not get the oils off of the surface of the water. As you drain, the oils just cling to the side walls and when you refill the boiler, they float on the surface again. That oil will make it very difficult for steam bubbles to break through the surface of the water and burst, producing steam.
There should be a skim port on the boiler somewhere above the water level that is used for skimming. Post some pictures of each side of the boiler and we can see if a skim port was installed. If so, we can tell you how to skim. It is easy but can take hours because you have to remove water from that port very slowly so that the oils drain off. If you don't have a skim port, we can probably tell you where it should be installed.

Dave0176

Wow the amount of poor piping pictures of late is unbelievable. SMH

Fred

@Bomba , I see, on the left side of your first picture that there is a pipe that is capped off. That pipe should have been used as a riser to a proper header. As @Dave0176 says, the boiler is piped completely wrong. Having said that, that capped pipe can be used to skim the boiler.

Neild5

The cap you are referring to would work to skim but is not where a vent needs to be. With a one pipe system the vents need to be after the last riser off or the main, you have 2 mains, follow both pipes coming off the attempt at a header, both the copper pipe and the white pipe. The main vent needs to be right before they drop to the floor.

Bomba

@Fred well that sucks. I mean its great I can skim the boiler, but I would much rather it be piped right.

How bad is it?

According to this image from the manual it shows only one pipe leaving the system - using only one supply tapping.

Bomba

Also,

After much searching, there is no vent. I do however, have a cap on where perhaps a radiator used to be. Can I put a vent there?

ethicalpaul

Hi there-- Your system has a lot of similarities with mine. I also had no main venting, also a Utica (although mine is 112K input), 1500 sq feet, 8 radiators, two story. See the helpful comments on my thread: https://forum.heatinghelp.com/discussion/167241/no-main-vents

I was really interested in your timings. I recorded mine the other day after returning home from a weekend away when I had turned down the heat to 60. Here they are for your info, but keep in mind there are some differences in our systems:

Cycle time during heatup from 65 to 70 degrees (Nov 11, 2018):
Outdoor temp 40 degrees
Living room and Bedroom radiators off due to leaking to be repaired
Minimal basement pipe insulation (all asbestos was removed)
These times are after the initial warm up burn from cold which I didn’t record:
1:57 burn time
1:09 cool time
1:57 burn time
1:12 cool time
2:07 burn time
1:10 cool time
2:10 burn time
1:10 cool time
2:10 burn time
1:08 cool time
2:15 burn time
1:03 cool time
:35 burn time (target temperature met)


Same day, but normal heat request from thermostat:
18:43 initial burn time
:58 cool time
1:41 burn time
1:00 cool time to 1 psi, then thermostat stopped calling for heat

ethicalpaul

KC_Jones said:

When you recover from big setbacks the radiators will fill all vents will close and you are at the mercy of the boiler size compared to radiation this is essentially worse case. That is what you were seeing and that's what I would expect. IMHO under normal circumstance and with proper sizing you shouldn't ever hit pressure limit. It's a safety not an operating control.

Sorry to jump in, KC, but I was really interested in your statement about not hitting the upper pressure limit. So I think you are saying that with ideal sizing (something that no original installation seems to have, all apparently being grossly oversized), what you will have is a "runup" from firing start to getting the thermostat from let's say 68f back up to 70f (with a 1 degree swing around 69f let's say?)

and that temperature gain has to happen before or shortly after all the vents close up.

Is that what we're shooting for with correct sizing? According to my observations, I am somewhat oversized because it takes me 2-3 cycles to get to the top of my swing. And that's with no insulation on my basement pipes. If I insulate those, then I think I will effectively oversize my boiler even more. I'm kind of looking forward to it failing so I can buy a (presumably) smaller one.

joshpjost

I have the same boiler. NBP should look like this:

Fred

@Bomba , see @joshpjost picture, above. That's what your piping should look like. On boilers with side tappings for the Risers, to the header, both should be used because those boilers are very sensitive to the velocity of the steam exiting the boiler. With just one riser, that velocity is higher and that carries more water (wet Steam) into the system. Some of it would drop out in a large header, but you don't even have a header.

To your second question, Yes, you can use an abandoned radiator run-out to add a vent to the main if it is at the end of the main. If it is near the beginning of the main, steam will close the vent before all the air can be removed and, for the most part, any air in the main beyond where you mount the vent will still act as if no main vent is installed.