New vs. Old Boiler Energy Use Differences Suprising to Us

cubicacres

Part of our research was that the old EGH-85 was an older series ( 4?) than our new EG-75 (5, I think), and WMC told us they reduced the heat output between those series after a review by the Dept. or Energy or something like that. That had them telling us the old series EGH 85 was equal to the new series EGH-95 or EGH-105 today. After counting & measuring all the rads, we thought the current EGH-75 was big enough-some say we should have gone with the EG-65 to get a less than 32% pickup factor. Here's a pic of our only wet return area next to the boiler. All 3 dry return loops coming back to the boiler room at the ceiling of the basement 6-7 feet up from the floor until the drop next to the boiler shown in my avatar pic & here. Was shortening the wet return lines by 5-8 feet with the new boiler a problem if it now doesn't have enough reserve water capacity? The condensate seems to return about 5-6 min. after low-water shut off this season (at least prior to our skim last week).

PMJ

> @cubicacres said:
> 5 uni apartment building with 4,900 sq ft total all 1-2 BR aprts. No condensate return tank. New boiler is on a few cinder blocks, no pad. Boiler room gets very cold with intake air, especially at floor level.

How much the boiler itself cools between firings is a big deal. Time from fire to full steam production is often overlooked. Combustion air source needs to be automatic and not lower the boiler room temperature or your jacket losses increase for no reason.

This is the area where I see my greatest efficiency gain with vacuum between cycles because time to full steam is so much faster with the burner firing in the deepest part of the vacuum. Really pretty dramatic difference in time to full steam.

The 2 places cycling steam boilers are most wasteful is the time they run at the start of each firing not making any steam at all(because the machine itself has cooled so much) and the time they run building pressure that is not needed for anything.

Your now colder boiler room may be subtracting more than you think.

MilanD

After what you said, I don't think the piping rearranging is the culprit. Smaller steam chest/boiler water capacity may be. But, I would think that, if you have enough of dry return piping to accommodate extra needed water capacity, you should be able to add water to the system and it should store in the dry return.

What I don't know is if this would affect overall water level in the boiler. If you have pipe capacity, you may need to convert part of the dry return into a false wet return, by piping it something like this attached pics1.

For this, I'd get someone more knowledgeable about this topic than me to confirm.

Fred

He says, in his other post that he loses a gallon of water a day. Find that loss and he is probably well on his way to solving a good portion of the low water issue. That amount of water loss coupled with normal amounts of condensate out in the system, on a boiler with a small water capacity to begin with. It's a combination of those things. I don't think the small amount of wet returns has anything to do with it. In fact it probably is an asset. I'm sure you have some pitch on the dry returns but is it enough, given the length of those returns to help speed the condensate along? May not have been a problem with the old boiler because it had a larger water capacity but may be more critical now. Still doesn't explain the water loss.

MilanD

Didn't catch there was an actual water loss of that proportion. Thanks!

Gallon a day is indeed indicative of a leak somewhere on the system, whether water or steam side: vents, valves, drips behind walls... that one might be hard to find if not in exposed spaces...

MilanD

Ok, just reread the post: replace spitting vents and see if that takes care of both water loss and condensate delay. That would be sweet if it's all there was to it.

As to energy use question, see if this solves it too.

cubicacres

Ok, we made a list of about a dozen things the water loss & higher energy use could be caused by, and replacing the last 4 long line gorton D/maid-o-mist D radiator vents with new ones (or smaller hoffman vari-vents) on that 2in loop we're planning on splitting sounds like the easiest first way to see if that was the problem with 1 gal/day water use.

Some people advised against such large D size vents on 9 EDR (1 wall hung), 25, or 40 EDR size 4-5 old column style radiators. Is the theory that too fast a vent allows too much steam & condensate in the rad, causing vent failure & possible water loss through the rad vent?

On the other hand, we made up half the difference a split in that 2in long main loop would make just by adding 4 D size vents to the last 4 rads on that long line if they can stay functioning where they are.

Fred

The typical problem with large vents on a radiator is that the steam can race across the top or bottom of that rad and close the vent before the air is pushed out so the rest of the rad stays cold. I don't see a large rad causing any extra condensate and certainly the rad won't take any more steam than it can hold. The faster times you see on the mains where those four vents are seems to me like it would mean you don't have enough venting on that main. Maybe the tapping that your main vents are on can't support the vents you already have on there and another tapping would be appropriate. Another option might be to drill and tap a hole on the riser(s) that feed those four radiators (before the radiator) and put your large vent there or as an alternative, tap the divet on the supply side of the radiator and put the large vent there (it will close when steam hits it and the smaller vent on the opposite side will vent the air in the radiator. I personally prefer the tap in the riser/supply pipe.
In any case, if you are splitting that main, it is a moot point.

New England SteamWorks

I am getting confused here, but if we are losing/cycling on low water I think that needs to be the first priority?

cubicacres

Update: we noticed it used 4 gallons of new water yesterday after going over there tonight! Looking back at the log the past 14 months, 0-5 hrs of boiler run time has about 1/20 gal/day water use(fall/spring season), 5-10 Hrs run time about 1/4 gal/day, 10-15 Hrs run time about 1 gal/day, and yesterdays 16 hrs run time was a record & used a record 4 gallons of new water in 24 hrs. The tekmar 279 showed a 63% boiler percentage for this most recent cycle, if that means anything. Temp was steady at 68F on the indoor sensor.

After swapping the front hall C size gorton radiator vent to a smaller new hoffman 1A vari-vent on level #5, our tennants in unit 1 happed to tell us that for 2 months they've been adjusting their bedroom rad vent since it kept spitting noisily & wouldn't close, along with a steam bubbling leak from the smaller bathroom radiator supply valve. We'll replace the BR vent tomorrow and research how to replace that bathroom supply valve or tighten the packing nut with that string stuff? we heard about.

We hope the wet steam pre-skim last week was why our energy use was so high in Dec, and these unit 1 leaks are why our water use was so high. If this fix doesn't do it, we'll be moving on to the next possibility after looking at the other radiators in the building.

Just curious, if we're at 111 gallons since install in Nov. 2015, how much new water can boilers handle (10, 100, 1,000 gallons before rusting out?)

MilanD

Man, I'd fire up the boiler an walk through all the units. Btw, what's your op pressure? This can be why vents are failing.

Steamhead

Tighten the packing nut first. 95% of the time that will stop the leak.

I think it's time to inspect all the radiators in the building.

MilanD

And pop in a few Steamaster tablets every few days until you figure this out.

Btw- depending on the age, these packing nuts can split if over tightened so get a few exras if you can, and few replacement valves before you start tightening. They also may need to be repacked. Grafite packing rope or there is now Teflon packing.

cubicacres

ok, here's a video I saw that goes over tightining the packing nut & the 2nd video uses teflon tape to tighten it up after shoving some in a few times & screwing it down to fill the gap https://youtube.com/watch?v=V9OkCbCRkL4

Is the first step to simply unscrew the handle on top of the radiator supply values or use small wrench if the handles broke off years ago and tighten the first nut down the spindle/shaft? Is this tightining the packing nut, or is teflon tape or that rope stuff need to be used?

We could also replace the whole valves & get new handles for the ones that are missing (we see old broken wooden handle pieces around the floor from 1900 when the building was constructed.) Do we simply shut off the boiler & use pipe wrenches to remove the old elbow supply valves & swap them with new ones? We're a little hesitant to do this in heating season in case something breaks

cubicacres

After looking at our boiler again today, we notice it starts the igniter, short loop with first rads gets steam 4 min after ignition, long loop with last rad steam established 9 min after ignition, then shuts off 10 minutes after steam established on long loop, so 19 minutes total run time with available water supply or from tekmar on 27% boiler % with our 40 min cycle.

This suggests tekmar shuts the boiler off naturally when weather is above 30F or so, but in colder weather it would need to run more than 10 minutes, so we're interrupting the steam production & losing several minutes of steam at the end due to running out of water, right? Is this the short cycling that uses 30% more energy than if it could run several minutes longer using the tekmar specifications without low water interuputions? Heating those pipes again seems wasteful as we're effectively making 2 shorter cycles instead of 1 adequately long one since it has to wait 5 min for the condensate to return after shutting off, then is still 1/2 inch low due to rad leaks & waits for both the cycle to end 40 min after ignition and then more time for the lockout differential to fall a few more degrees before starting up again since the tekmar only allows one start & stop per cycle. While the last week was only 5F it still heated the rooms 65-68F, so does this also prove our boiler is large enough if it can keep up with no more than 19 minutes run time each "short"cycle?

Fred

Having the boiler shut down for five minutes isn't going to allow the mains to cool enough to waste 30% of your fuel.
The best advice, at this point, since you said you have a list of about a dozen items to check out would be for you to Prioritize that list and work through each of those issues until it is resolved, beginning with where the water is going. Check each rad, vent,valve, run-out for leaks, risers(look for wet spots on apt. walls and ceilings, and all fittings. Once you have that problem resolved, move on to the next highest priority on you list but don't move on until you are satisfied you have resolved the higher priority problem. You are jumping between problems to much. You'll never get to the source of each that way. When you fix the higher priority problems, you may find that some of the other items on your list disappear.
If it were me, When you get to cycle times on your list, I'd start with the basic controls (no tekmar) and see how the boiler performs and then add that component back into the mix and note how it changes the general performance. Also, when you get to the Low water issue, on your list, you may find you will have to add a condensate tank. There may not be an option given what WM says in their manual.
Take it one item at a time and stay focused. You'll get there!

EBEBRATT-Ed

@Fred I agree with most of your last post but I don't agree with "Having the boiler shut down for five minutes isn't going to allow the mains to cool enough to waste 30% of your fuel"

Short cycling can kill a fuel bill.

I agree with as I said in an earlier post "tekmar, low water or pressure control find out what is causing it to short cycle and then you can fix the problem.

every time you fire up you fill he piping with steam. You don't want the steam condensing in the piping and loosing all the latent heat you just burned fuel to make. You will have a warm basement and burn more fuel to heat the radiators

Think of it this way, every time you make steam you need to heat the building fully and drive steam to the radiators sure you will condense latent in the piping 1 time per cycle.

Increase he # of cycles beyond what keeps the home comfortable and you waste fuel.

Fred

@EBEBRATT-Ed , I took a swag on that. 30% just seemed to high to be just related to a five minute shutdown once or twice a heating cycle, at least in my opinion but I have nothing to back that up. It just seemed to me that if a cyclegard shuts the boiler down for 10 minutes, every 10 minutes that we would hear a lot of people complaining that their fuel bills have jumped significantly and the Cyclegard would never be used.

EBEBRATT-Ed

@Fred, I know, who's to say? We haven't seen the job. But it's strange to burn more fuel with a new smaller boiler that is supposed to be the correct size.

If the piping is right and no wet steam and the vents are right

I can't think of anything else but short cycling.............

Fred

@EBEBRATT-Ed , he lost 4 gallons of water yesterday. He may be burning more fuel bringing the water back up to temp than anything else???? That's why I suggested he give that top priority but, like you said, who knows?

MilanD

I replaced some vents and installed a vaporstat at work. From last to this year, better venting and smaller psi = lower bill for same comfort. My bills went down significantly comparing dec 2015 to dec 2016, and Nov to Nov. (I know apples and oranges, buy hey, makes me all warm and fuzzy.)

Psi came down from about, oh 2.5 to 3 psi (never measured it but trol was way off when I replaced it set at 1 with 1 diff showed 1 on 3p psi garbage gauge), to, I just bumped it from 8 to 9.6 oz per 3 psi gauge (0.6 psi).

First figure out water loss. 4 gal/day is way way off. Then, vent vent vent... Then lower that psi... way way down on a vaporstat...

cubicacres

Today at 30F the tekmar shut the boiler down, but yesterday it was low water. About 5 min after low water shut down the condensate came back to 1/2 inch under the normal level, so we lost some water, then it took about 10-15 more minutes for the 40 min cycle to end, then another 10 min or so for the lockout differential to allow the next cycle to start. Maybe it started up about 20+ minutes later due to the interruption on low water?

Even with these delays due to leaks/low water shut down/short cycling causing inefficiencies, the indoor sensor is within 3-4 degrees of the target each day (even when 5F outside last week), so does this at least rule out one of the potential issues being that our boiler is too small to properly heat the building (if is has heated ok while short-cycling)?

PMJ

Fred said:

@EBEBRATT-Ed , I took a swag on that. 30% just seemed to high to be just related to a five minute shutdown once or twice a heating cycle, at least in my opinion but I have nothing to back that up. It just seemed to me that if a cyclegard shuts the boiler down for 10 minutes, every 10 minutes that we would hear a lot of people complaining that their fuel bills have jumped significantly and the Cyclegard would never be used.

You are right about this @Fred. I think a more precise definition of "short cycling" is required. Cycling to hold pressure when it is not needed for anything is what is wasteful. Just shorter cycles with no pressure at all doesn't waste anything. Using evenly spaced shorter cycles to spread the runs out so there is never any pressure I believe is the most efficient with the least overshooting. This is basically what the fancy controls do. Insulated mains take quite a while to cool enough to be a factor in anything during any period when you actually need heat. There is no way just extra cycles are causing a 30% increase in the bill unless the system is cycling to hold a pretty significant pressure. Extra cycles can't cause water to actually leave the system either. Something else is wrong here.

Fred

@cubicacres , I believe you boiler is sized fine for the connected EDR you have and I would not spend one minute of my time trying to validate the sizing. Find where the water is going and you will likely allow the boiler to make steam rather than heat cold added water and may also solve your low water shut downs, in that process.

cubicacres

Does tightening the packing nut simply mean using a wrench to tighten the first nut below the top of the shut-off valve at each radiator if it's loose? If we add the handle if it's missing on top & it spins loosley after tightening the packing nut below, does that indicate the packing washer needs to be re-packed with that rope-type material we read about?

Fred

cubicacres said:

Does tightening the packing nut simply mean using a wrench to tighten the first nut below the top of the shut-off valve at each radiator if it's loose? If we add the handle if it's missing on top & it spins loosley after tightening the packing nut below, does that indicate the packing washer needs to be re-packed with that rope-type material we read about?

Yes, the nut below the valve handle. The handle should not spin freely. There should be a little resistance. May indicate the need to be repacked or the stem has come loose from the disc inside or both.

cubicacres

Here's a pic of our typical radiator shutoff valve areas (about half are missing handles). This was the one our tennant mentioned & it had water leaking down the stem today, so we suspect this is part of the problem.

Fred

Looks pretty rough and judging from the looks of the grout line around the perimeter of that floor and the rust on that chrome escutcheon, I would guess water runs down the pipe and onto/under the flooring and has for quite some time. If there are many in that shape, they all should be fixed.

cubicacres

Thanks for the suggestions & advice everyone! I think we'll visit all the rads as our next step and see what we can find. Is the list below a good way to proceed as we visit each one?

1. tighten packing nut if lose
2. Add teflon plumbers tape to bottom of shaft on top of nut & turn handle (after adding a new handle or just use a pliers) a few times to work it down in there to seal the gap with 3-4 applications of tape
3. If it still feels lose with the handle after this & spins without some tension, add rope to re-seal the washer (is boiler shut-down needed for this step?)
4. If this doesn't work, replace the whole valve after measuring what size replacement we need & shutting down the boiler (simply use a pipe wrench to remove the union on the radiator side, then remove it from the vertical riser?) If we're doing this, would be want to try and clean out the bottom of the radiators as well somehow, or just leave them alone?

In the meantime, we could try adding a few steamaster tablets into an open port (or 8-way?) like the skim port per the manufacturer's instructions. Since we can't boil more than 20 minutes or so with the current leak before low water cutoff occurs, we won't be able to do the full 1-3 hr steam cleaning treatment for dirty boilers, just the maintenance level one per the product sheet instructions? Are there any risks to adding the steamaster tablets or 8-way to our system? (Smelly radiators, clogs, etc. other than being careful handling the product)

Fred

If the valve leaks around the stem and tightening the packing nut a bit doesn't stop that leak, teflon tape is only a temporary fix. The valve needs to be repacked with either graphite packing or teflon packing.

Boiler does not need to be shut down to tighten the packing nut but does to safely repack.

If the valve has to be replaced, the boiler must be shut down and you must also replace the spud, in the radiator, that comes with the new valve. They are a matched set. The union connection will leak if you try to use the new valve with the old spud.
You don't need to try to clean out the radiator.
I would not use more than one or two Steamaster tablets in the boiler. More than that and most people see pressures rise, foaming, and very unstable water levels. I personally would not worry about adding the Steamaster tablets until I was comfortable I had virtually all the water loss corrected. Cleaning the boiler right now is not a priority and has nothing to do with the water loss.
Remember, fixing the valves that leak may not be the only source of water loss so continue to survey all the other potential sources of leaks as well but start with the valves if you feel that is the source of significant water loss.
Stay focused on finding and fixing the water loss. THEN See if that helps with the Low Water issue and maybe even the fuel consumption.

cubicacres

Thanks Fred. Might the temporary teflon tape fix get us by until the heating season is over for replacement of the entire valves if the simple tightening of the nuts doesn't stop the leak?

I called Hoffman/Xylem/Gossett and they said they no longer make iron/black steel valves, so just the brass ones I saw at supplyhouse seem available so far. Is brass ok with our current iron risers & radiators to avoid diaelectric union issues? They come with a short nipple pipe-is that the spud you mentioned?

Fred

@cubicacres , the teflon tape may get you through this season, maybe??
Yes the brass valves are fine, better actually. That pretty much all you can get anymore. No problem with mixing those with the black iron pipe at all. And yes, the short nipple that comes with the valves is the spud.

EBEBRATT-Ed

But the radiator valves leaked with the old boiler as well. Something else going on.

I am not suggesting that they are not important to fix every little bit helps.

@PMJ said" Just shorter cycles with no pressure at all doesn't waste anything."

I don't agree. You want the longest cycle you can get without "swinging" the building temp excessively.

like I said previously, every time you make steam you fill the piping with steam. What ever doesn't make it to the radiators looses it's latent heat to the basement.

Lets say you start the boiler and when the steam gets to the end of the main you shut the boiler off. The rads and branches are cold and the building is cold. wait 20 min and start the boiler again. repeat...repeat.

isn't the boiler short cycling and burning fuel for nothing??

Same thing that happens when you have plugged vents a lot of fuel burned but no heat.

Fred

I am soooo trying to get the OP to focus on the highest priority item on his list, which is the water loss, and not get side tracked. Per my earlier post, he needs to check/find/fix leaking valves, vents, pipes, fittings, anything that can potentially leak. Losing 1 to 4 gallons of water on a new boiler is extraordinary especially when all his wet returns are above ground and that much water should be visible, even if it's a wet wall or ceiling, otherwise, it is quite possibly/likely a combination of small leaks.

PMJ

EBEBRATT-Ed said:

But the radiator valves leaked with the old boiler as well. Something else going on.

I am not suggesting that they are not important to fix every little bit helps.

@PMJ said" Just shorter cycles with no pressure at all doesn't waste anything."

I don't agree. You want the longest cycle you can get without "swinging" the building temp excessively.

like I said previously, every time you make steam you fill the piping with steam. What ever doesn't make it to the radiators looses it's latent heat to the basement.

Lets say you start the boiler and when the steam gets to the end of the main you shut the boiler off. The rads and branches are cold and the building is cold. wait 20 min and start the boiler again. repeat...repeat.

isn't the boiler short cycling and burning fuel for nothing??

Same thing that happens when you have plugged vents a lot of fuel burned but no heat.

@EBEBRATT-Ed,

Perhaps we should take this up elsewhere if you like. I don't want to cause a distraction to this thread. But I have run for years with deliberately shorter cycles with improved efficiency. I will put it up against any system with longer runs that stops regularly against a vaporstat. I do not think extra cycles are the problem here unless they are stops against pressure.

EBEBRATT-Ed

@PMJ, just my opinion that's all it is. Like I mentioned to @Fred , if we were on the job we would probably all come to the same conclusion on what is wrong.

I used to work with an old timer (now I am one) we would go to the job together and start troubleshooting. Sometimes he went in one direction and I went in a different direction. We usually ended up in the same spot with the same diagnosis.

cubicacres

When we observe the Hoffman vari-vents & Gorton C & Miad-o-mist D rad vents, they should release air as steam fills the rad for a few minutes, then shut off & be silent until they open again when the steam condenses in the rads several minutes later? Maybe a pop or closing sound as they open & close? Other than that, no other sounds from them? If we notice sputtering, water gurguling sounds, constant noise, or water leaving them, they need cleaning or replacement?

MilanD

Yes. Some hissing and popping is normal. Since this is a rental, and you have no way to monitor vents over a few days, I would replace anything spitting water, dribbling, dripping, or otherwise leaking. Sometimes they get stuck and don't seat propperly due to dirt being blown out from the system and just shaking them and rinsing them out can make them seat well and seal back up. Not to make more work for yourself, if I were you, I'd replace.

Did I read somewhere these are fairly new vents? If so, don't throw them away. You can shake out water out of them and maybe even soak them in water / vinegar solution over a simmering boiling water for 10-20 min. Then test them on a visible rad (like a halway), and see if they work. You'll have plenty back up vents.

If these were newer vents, and are in fact blown since new boiler was installed, I'd tackle venting and op pressure next (and at the same time), but not before, and first, checking all pipes and rads to find and remedy any and all leaks.

cubicacres

Thanks-we're heading over there now to check out the apartment rads. All new vents since new boiler install in Nov. 2015. We just got a text that spitting rad in bedroom unit #1 is better now since we replaced it 2 days ago, so we'll see how it looks again in a few minutes.

cubicacres

After checking rads in units # 1, 2 & 5 of 5 units yesterday (still have #3&4 to go tomorrow), we tightened a few valve supply nuts up to 1.5 turns, some were already very tight, checked the pitch of the rads, most were fine and sloped back to the supply side a little with 2 just about level but hard to lift up since too heavy to shim ourselves, and replaced 1 sputtering rad vent-the others looked & sounded ok. A little steam when on our hand-mirror when they were filling with steam, then none after the boiler stopped, so we thought that was ok. The rads all heated up mostly or all the way across the sections. The one room that was a little cold at the end of the long line had a smaller rad, so that could explain it.

If we can't find any other rad /supply valve leaks tomorrow, we might try starting with the near-boiler piping (removing the insulation to watch for leaks on startup) and going up the mains visually to the risers looking for leaks. Would a visual inspection then replacing the insulation with tape be the way to go, or try soap bubble detector, or an IR camera? If no leaks found, next it's the risers in the walls that could be leaking, but that sounds harder to investigate.

One explanation for the EGH-85 over-sized prior boiler rusting out 10 years after install in the late 80's under warranty replacement in the late 90's, then a second block nearly disintigrated when we bought it in 2015 might be a leak that was never fixed? If shut-off on low water occured for the prior owner, that might be why he said he spent twice as much to heat this building as any of his other buildings.