Is Main Vent (Vent-rite 75) large enough on this one pipe system?

Fred

Jack M said:

Won't I loose a ton of boiler water if I let the LWCO just flow out the bottom through the blowdown valve? The I'll have to add that same huge amount of (oxygen laden) water back into the system. Is there a shutoff from the boiler that would just let the LWCO drain without draining the boiler?

You may loose a half gallon or so of water but that's all. Replace the water after testing and fire the boiler up for about 15 minutes. That will drive off any extra oxygen in the added water.
I have a float type LWCO also and I blow down and test once a week. Safety comes before any concern over a little water that has to be boiled for a few minutes.

Jack M

OK, so that worked. The LWCO stopped the boiler when I opened the blowdown valve. When I do my once a week purge of the LWCO should I be letting that much water out? Should I be letting out enough water to trigger the LWCO and kill the burner?

Fred

Typically if you let water out until it runs clear, that will be a half gallon to a gallon. and that is about what it takes to test the LWCO.

Abracadabra

Jack M said:

Won't I loose a ton of boiler water if I let the LWCO just flow out the bottom through the blowdown valve? I'll have to drop a lot of water before I get down to the shutoff line on the LWCO. Then I'll have to add that same huge amount of (oxygen laden) water back into the system. Is there a shutoff from the boiler that would just let the LWCO drain without draining the boiler?

The float chamber empties faster than it refills. You are basically just emptying the float chamber plus a bit more. You're supposed to flush the chamber once a week anyways during heating season.

Jack M

Looking at replacement boiler options I see that the Crown FSZ100 Freeport Boiler (3 pass cast iron/ retention burner) doesn't have a Hartford Loop in the dropped header. What's up with that?

Abracadabra

The Hartford Loop is there. It's the wye item #14. The wye replaces a close nipple & tee.

Jack M

The wye? That small device attached to verticle pipe above the return?

Abracadabra

yes

Jack M

If that lower return rusts out, won't all the water flow out of the boiler and onto my basement floor? I understood that the Hartford loop was intended to prevent the water from leaving the boiler should that return fail. How is the wye going to prevent a failed return from creating a dry boiler problem?

Fred

That Wye is a plumbing fitting. Instead of being a TEE (T) shape, it is a Wye (Y) shape. Your wet return plumbs into that Wye. If the wet return leaks, it won't keep the all the boiler water in the boiler, just what water is below the Hardford loop connection. Some water will be on the floor but the boiler won't be dry.

Jack M

I get it now. It sure takes a keen eye to understand these pipes. All the systems have their nuances. I was looking at this Crown Bermuda boiler that is sized for my system but the pipes seem wrong compared to what Crown provides in their near boiler piping kit.

Abracadabra

Indeed... mainly it's all copper, which is a no-no for steam.

KC_Jones

Piping is wrong and so is the material. Copper should never be used on steam carrying pipes.

Jack M

Do people ever install used steam boilers? There are so many people running from steam to condensing boilers, minisplits, and heatpumps. Used high quality wet boilers show up frequently with only 2 or three years of use (most of them oil fired). Do all those used boiler just get scrapped? Do they ever find their way back into service?

Fred

There probably is a very small market for used boilers. Why? Probably because the labor costs to install it correctly is a major component of any steam system and those costs are the same, new or used (maybe more on the used system if it needs missing components or any repairs).
The end result is an unknown.
There is no warranty on used units (even though it may be only a couple years old) most warranties say "To the original owner, at the original installation address".
Shipping costs from a private owner to your address pays a portion of the difference in costs (New Vs. Used).
Most people are leary of buying someone elses problem(s)
I'm sure there are other reasons and that others will chime in.
Of course if a person can't afford a new unit, plans to install it themselves and a neighbor, that you trust, close by, is giving it to them or selling it for little or nothing, a good used boiler is better than no heat. It's the luck of the draw.

Jack M

I have two choices for installing a low pressure gauge and vaporstat. The threaded hole where the existing 0-30 gauge is installed or there's a bronze plug just to the right of the gauge.
I'm sure neither of these have been removed in 15 years. Is either of these a better option than using the threaded hole on the LWCO? If I strip something out I'm be kicking myself.

Fred

Spray a little penetrating oil on the threads of the old pressure gauge and it should come right out. I moved mine from the top of the LWCO to where the old gauge was and it was a piece of cake.

Jack M

If I use a penetrating oil will I need to skim the boiler afterward?

Fred

No, it will stay on the outside threads and maybe one thread in the boiler block not enough to wash into the boiler.

Abracadabra

Make sure the replacement gauge has an internal siphon or add a pigtail.

Jack M

The new gauge is on. After 40 minutes only two of the radiators has heated across and closed its vent. The pressure has not changed at all from what I can tell.

Jack M

Once all the radiators filled I could hear their vents close (except for the new gorton) Once those radiator vents closed the pressure started to climb. This all happened at the 50 to 55 minute mark. Watching the pressure gauge and checking the radiators, the radiators were pretty much full of heat when the pressure gauge read .5 pounds. Does that mean I could set a pressuretrol or vaporstat to shut the burner down at .5 psi instead of keep trying to run? I did not let the boiler run until shutoff only because I had no idea how long that would take. The highest the gauge got was 1.2 or 1.3 psi at the one hour mark. Then I went to bed

nicholas bonham-carter

Your time to the heating of the radiators seems abnormally long. Have you tried timing it with the main vent removed [use caution]?--NBC

Mark N

Why is the boiler running so long as to heat the radiators all the way across? The weather has been some what mild. Was the thermostat set to maintain temp or was it turned up a few degrees? Radiators should only heat all the way across on the coldest days. At zero out mine still don't heat all the way across.

Jack M

Yes, I turned the thermostat up two degrees (to run the test of of the gauge). Also, my wife set the dishwasher's timer to run without me knowing it (I can never hear the dishwasher). Not sure if the dishwasher draws hot water. With some pressure in the system I was able to find and fix a radiator valve that was leaking. And I now know my system is not running at 15 psi like the old gauge said. I still don't know if the old pressuretrol would have shut the boiler down on its own. I think I may understand why the radiators should all have vents by the same manufacturer. The Vent-rite and Gorton vents seem to open and close at slightly different temperatures.
Tried everything again this morning.
The outdoor temperature is 38F.
I started the boiler this morning at 7:45am the room temp was 60F. The main vents were at 60F as well (used an infra-red thermometer). I watched the main vents and they both closed at 7:52 am. (Only 7 minutes from the boiler start time). Their temp (closed) climbed to 130F (gorton 2) and 87F (Vent-rite 75). By 8:04am the first 2-3 sections of the radiators were filed (20 minutes from start time). At 8:08am (23 minutes from start time) all the radiators were heating half way across (4-5 sections depending). The room temp has climbed 2 degrees at the 24 minute mark and the boiler has shut down. Never any movement at all on the pressure gauge. Dead zero.

Fred

23 minutes to raise the temp 2 degrees is not bad at all. Just remember the goal is to get the temperature in the house to the temp you set on the thermostat. Not to heat all radiators all the way across. To your comment about using all the same radiator vents, that's not something you have to do. Any working vent will close when the steam hits it. Even the same brand vent may vary a few degrees to close and the size of the vent will also affect closing times.
The fact that you did not build any noticable pressure during that 23 minutes is a good thing. Any boiler that runs for an hour will build some pressure.
You need to make sure your Pressuretrol is working. You don't want to set the Cut-Out pressure at .5PSI. That is what your Cut-in pressure should be. Cut-out should be set at 1 to 1.5PSI. Setting a Pressuretrol too low often cause them to not reset after the initial boiler run. Keeping the pressure at or below 1.5PSI should be your goal.
It sounds like you use a fairly deep setback on your thermostat. That doesn't play well with Steam heat. Any setback more than 2 or 3 degrees makes the boiler run longer and builds unwanted pressures and causes short cycling, especially if the boiler is over-sized.

Jack M

I'll abandone the deep setback and see how things go. I read Dan Holohan's comment about not needing to worry about deep setbacks in a column here:
grist.org/living/ask-umbra-whats-the-most-efficient-way-to-heat-the-house/
I have also been reading through this very long thread here on the Wall on the subject of setbacks:
forum.heatinghelp.com/discussion/152822/is-there-fuel-savings-with-deep-setback-with-steam-heat/p1
Can I go with a one or two degree setback at night, just so the boiler is cued up and triggered to run when I go to take a shower in the A.M. and the kids can leave their sweaters and pants on the radiators while they get dressed for school? Would that be ok?

Fred

Oh yes, that link. You're opening up yet another Can of worms!

Mark N

Most people who do set backs never keep comprehensive enough records to quantify their savings. I've been keeping records for 6 years now, ever since converting from oily to gas. What needs to be tracked is the amount of gas or oil used just for heating, not total usage. Over the last 6 years I've averaged 659.016 therms for heating per year. The cost has gone down every year since I converted. I don't use set back. The thermostat is set at 70 from the middle of October until beginning of May.

Fred

Here we go

Jack M

One radiator is slower to heat. It's the largest radiator and on a north wall. It's an American Standard (3 column/10 section) radiator with an EDR of 50. The radiator is at the end of a 23 foot 1.5 inch pipe. I replaced the vent on that radiator with a larger Gorton #6.
Now I'm thinking that if I could vent that long 23 foot pipe with a "main vent" I might save the radiator and save the vent from all the work of expelling all that air. Is this thinking correct? I have 12" to work with between the pipe and the ceiling. (note: the knob and tube is not live, just there for effect).

Fred

You don't want to put a Main vent on any radiator run. Maybe if you had a multi-story riser feeding multiple radiators it might be an option. Doing that on one radiator run will just throw all your efforts to balance your system off. That radiator will get hot first, over heat that room and then the others will be slower getting steam.
Radiator vents are designed to vent the radiator and a typical run out supply pipe.

Jack M

OK, I'll abandone the idea of adding a main vent to that radiator run. Thanks. I can hear the air coming out of the Gorton #6 that I put on that big radiator. All the other radiators have adjustable Vent-rite (very old ones with no numbers on them). The vent-rites do not make any hissing sound at all. They are silent. Should I not have installed that Gorton #6? Am I throwing things out of whack?

Fred

That #6 will vent twice as fast as a Vent Rite at its highest setting.
50 EDR is not a huge radiator, probably more what I'd consider middle of the range. You are hearing the air escape because it is venting at a higher rate (moving more air) than the others. That, by itself is not a problem as long as it doesn't create any issues at the other radiators, especially since its at the end of the Main.

Mark N

Chris J has added vents to some of his run outs to the rads. He would be able to give some info on its effectiveness. There is an article "It's All in The Venting" in the Heating Museum. Give it a read.

Fred

Keep in mind @Chrisj added regular radiator vents to a couple run-outs, just before the radiator valve, not a Main vent. If he chimes in on how effective that was, hopefully he will tell us what size it was along with the size of the vent on that radiator. I'm going to bet, the two vents together aren't much bigger than the #6 Jack M already has on his radiator.

Abracadabra

You can add a "D" vent to the supply side of the radiator. There should be a boss there that you can drill and tap, similar to the far side of the radiator. I've done this in situations where I needed to vent a long riser/runout.

Jack M

I'm beginning to realize just how complicated these "simple" steam systems really are. During the coldest days of the year, the radiators should fill all the way and the boiler should run non-stop all day and stay below 1 psi, and all the while keep the each room in the house (no matter what the weather) comfortable. Then in early spring the same system needs to boil just the right amount of water to generate enough steam (but not so much to cause fluctuations in temperature from warm to cool). Can a non-modulating boiler really do all this? Is this a realistic expectation? Aren't there sophisticated computerized condensing boilers that struggle to pull this off? Are we asking too much of a steam?

BobC

You probably can't make it perfect but you can make it work pretty damn good. It's a question of balance, you have to shift things around till it works as best as it can for your particular system.

My old boiler was rated at 596 sq ft of steam and I only have 200 EDR but I got that boiler to heat evenly and reasonably efficient as well. It short cycled but the heat was good and it was even.

Bob

ChrisJ

Yes, I did this on one of my bedroom radiators to gain more control over it via the TRV. Basically my objective was to get steam to the radiator very fast but then slow down the radiator it self. This way, if the TRV wanted steam it was there, if not, it didn't get any. Because it's on the second floor a G4 was just way too slow to vent the pipe and still get some heat on mild days.

It worked very well using a G6 on the pipe and a G4 on the TRV. However, I switched things around thanks to the EcoSteam. I plugged the pipe vent and now just have a G5 on the TRV.

Previously, this would cause overheating constantly in the room but since the EcoSteam encourages more, shorter cycles it allows the TRV to really keep things really nice. The reason I switched was with the G4 and the shorter cycles I wasn't getting enough heat in there on really windy days. I have 3 huge drafty windows on the north side of the house and it just couldn't do it. With the G5 I can get a several degree rise in one cycle now when need be thanks to a grossly oversized radiator.

I am however considering doing this on my downstairs bathroom radiator. Reason being I have a G5 on it, but it's long pipe kinda delays things. A G6 causes the steam to take a shortcut across the bottom and shut the vent so I'm thinking a G6 on the pipe side and a G4 or 5 on the radiator side.


Wow, sorry for the long response.