Questions on New Gas Boiler

mroberts5

I recently had my V85S replaced with an IN7 and have a few questions:

1. I am planning an addition to my house for next year and sized the boiler considering this. I have about 350 EDR now and will be adding another 150 with the addition. Because of this the boiler is currently quite oversized. The contractor downfired it by throttling the isolation ball valve in the gas line. He did run all draft and combustion tests both full and throttled and was comfortable with what he got. Does this sound acceptable and do I have any better options to run a 70% oversized boiler for the season?

2. When I ran my calculations I asked for a IN6, but the contractor recommended an IN7. I listened and now I'm worried I made a mistake. 500 EDR x 240 BTU/EDR x 1.2 pickup (fully insulated pipes, rather direct runs) = 144 - exactly the DOE rating of the IN6. Do you think this is a big enough deal to considering swapping out? I'm running ~1psi out / 0.5psi diff on the pressuretrol, with big mouths on the mains and Hoffman 40s or 1As set low on the rads. Hissing vents drives me nuts, and I'm worried thats what I'm in for...

3. Can you share any opinions on the near boiler piping? Two things jumped out as odd to me: 2" pipe was used as a mini riser to get from the header to a 2.5" counter-flow main. Is this restriction ok? And a plugged tee was used instead of an elbow - any concerns there (photos attached - note - I've since insulated all of this piping





4. Third random question: From the previous owner a number of radiators have glass plates sitting on the radiators. Any thoughts on why and what the effects are? They are tightly inset into the wall, so my only thought was to protect the wood paneling near them (photos attached).



5. Below Ironman raised concerns that the oil water heater is sharing the same flue. Do you all agree?

Thanks!
Matt

Ironman

Open that gas valve all the way!

The size of the mains depends upon the connected EDR, not necessarily what's already there. Was a radiation survey done?

Ironman

Also: that gas boiler should not be common vented with the oil burner.

Fred

From what I can see, the near boiler piping looks pretty good. My only question is, from the picture, it looks like the header may be slightly pitched away from the equalizer. Is it? Maybe it's just the angle of the picture. It should pitch towards the equalizer. The Riser tappings on the Burnhams is 2" so he used the full size of the tappings and it should be OK. I see he installed a skim port. That is good. I also see what looks like two mains tied together on nearest the wall, where one goes up and the other turns the corner. It would have been better if each of those were tied, individually into the header but at least it's not a Bull Tee and it should work alright.
I also see you have labeled that one main as a counter flow. If so, where is the Drip for that main? You don't want the condensate flowing back down the riser and into the header to get back into the boiler.

mroberts5

Last time I opened it fully I was getting terrible hammering. I've been flushing & skimming quite a bit since then. I'll try again, but if it continues...then what?

That 2" pipe will handle 225EDR. Per the charts I'm looking at 2" riser is good for 288 and 2.5" main is good for 260. So I'm good? That little section of elbows and unions isn't exactly a riser though...

As for the oil water heater - it will eventually be replaced, but I was under the impression oil and gas could be combined (both from my research and the contractor). Separate note: When I had the oil boiler there was an interlock on the water heater, which cut it out if the boiler was running, but that has since been removed.

Ironman

Something's wrong if you can't open a gas cock all the way. You need a pro with a manometer and a digital combustion analyzer that knows what he's doing.

Is that a 2 psi gas system?

mroberts5

Here are two more photos (not very good).

The header pitches down towards the equalizer pretty aggressively, its just hard to tell in the photos.

The "main" that comes into the counter flow main only feeds one small radiator (22.5 EDR, which may be removed anyway).

There is no separate drip. Where would you tie in the drip line?
Does it matter/help that the counter flow header is AFTER the wet return header?

mroberts5

I'm reading more about counter flow piping - I see multiple references to having the header come DOWN into the main. Should I have gone up and then back down, and then dripped the end of the main like below? And if so, what will doing this gain me?

Ironman

The way the counterflow is connected right next to the Ell of the equalizer is effectively doing the same thing as a drip. The plugged Tee should be removed and wouldn't be necessary if the Ell before it was rotated.

If there are no issues, I'd leave the steam piping alone.

The gas! You've got a major issue!

nicholas bonham-carter

Here is one of the excellent documents produced by Peerless boilers. Page 1 shows the ideal, and required piping for a counterflow system.—NBC

https://www.peerlessboilers.com/wp-content/uploads/2017/12/Survey_Stm.pdf

mroberts5

I see it now. And I checked photos of the piping on the old boiler and it was right. I spoke with the contractor already and he's coming to look this week. Fingers crossed that he's agreeable to redoing it.

I opened the gas valve fully and while I'm getting quite a bit of "water" noise on the counter flow side, it's no where near as bad as when the water was dirtier.

So what I'm hearing is there's really no good way to down for this until next year?

Also, any thoughts on those glass plates?


Thanks everyone. Super helpful!!

mikeg2015

I agree that the IN6 would have been better. Especially with a counterflow that will have less header piping than a parallel setup. Until you add 150 EDR extra, you are very oversized. If nothing else it's 10% cheaper. I would have installed an indirect tank and gotten rid of that other water heater.

Neild5

The glass is restricting the convention heating, I don't have my copy handy but in Dan's book I've Got Steam he covers how to calculate the affect of the cover.
Also it may be the flash but the gas line looks like it is galvanized, some utility companies do not allow it.

Erin Holohan Haskell

Here's more info on radiator covers: https://heatinghelp.com/heating-museum/radiator-enclosures/

mroberts5

I spoke to the installer today. He said he installed it this way on purpose. That because the rest of the system was parallel flow, that tying the drip in the wet return would throw off the pressure balance in the equalizer (???)/

I'm certainly no expert on these (but am an engineer), and have read through Dan's The Lost Art...everything else the installer has said sounded right on to what I've read. But I'm not sure on this one.

So - any further thoughts? Does having a system that's half parallel flow and half counter flow change if you come in from the top and drip it?

Another point you can't really see in the photo - the riser from the header to the counter flow main comes out at a 90 straight up. From what I've read, also not advised...

As for the gas: he says that since he analyzed the combustion and measured the draft, hes totally comfortable throttling down the gas.

On a final note, I installed a vapor stat today to try to keep the pressure down (still fighting loud vents). I'll be tweaking the cut in/cut out and I'll see how that does.

Fred

Where is the drip for that counter flow main? I don't see it in the pictures. If he is calling that riser into the Header a drip, he is wrong. That is a steam supply and the drip should come after where the supply riser ties into the main and drop down into the wet return, below the boiler water line so that returning condensate doesn't fall back into the header, with the steam.

mroberts5

There is no drip on the counter flow main. That is what he's saying he doesn't like using.

1Matthias

Oi vey... It is possible to have both. And the counterflow needs a drip. Period.

nicholas bonham-carter

Here is the Peerless boiler company explanation on piping both counterflow, and parallel flow systems-what a good company they are-NBC

https://www.peerlessboilers.com/wp-content/uploads/2017/12/Survey_Stm.pdf





Sent from my iPad

Fred

He might not like it but he's not the customer or the manufacturer. A counter flow main needs a drip to prevent water from running back into the header. It is going to hammer at some point during the heating season.

Ironman

This guy's making up his own rules which contradict proven ones.

Please hear me: you CANNOT throttle a gas cock to try and correct the firing rate or combustion numbers. SOMETHING IS WRONG if that has to be done!

I would highly recommend that you get a competent technician that knows how to setup a gas boiler. Your safety, and your family's are at risk. You're risking fire, CO poisoning or explosion.

Ironman

As far as dripping a counterflow into a wet return, look at these pics of the boiler that we just did for the lady in CT.

https://forum.heatinghelp.com/discussion/167842/volunteer-work-party-for-a-repiping-job/p4

DZoro

Listen to @Ironman ,
Absolutely cannot throttle the gas like that!!!!! Period...…
D

pecmsg

So what Combustion Tests did he perform with a “Throdled” gas valve?

He did run all draft and combustion tests both full and throttled and was comfortable with what he got.

mroberts5

Yes, he ran co and o2 tests and measured draft full and throttled.
I've opened it fully.

I will reach back out and press harder to repipe it....it just do it myself. It sucks being in the position to have to argue w/ someone who has 20 yrs installing steam systems....

EBEBRATT-Ed

The piping is not right. Counter flow needs a drip. The IN6 is rated 450 square ft of steam so the IN7 is the right boiler if your EDR is going to be 500

The boiler should have 2 2" risers that you have. It should have a 3" header regardless of the size of you steam take offs. Then both steam take offs from the header should match the size of your two steam mains.

The main that is counter flow should have a drip and that drip should be tied into your equalizer below the water line. The equalizer drains the header. The counter flow drip drains the condensate return from the counter flow supply.

The equalizer shouldn't be doing double duty and the condensate coming back down the counter flow supply will kill the steam in the header and could be causing your noisy vents.....panting. Can't bring condensate back into header

mroberts5

Can the drip go into the wet return (copper piping), or must it go into the equalizer (steel piping)?

pecmsg

COPPER?> @mroberts5 said:
> Can the drip go into the wet return (copper piping), or must it go into the equalizer (steel piping)?

EBEBRATT-Ed

it can go into whatever is easier as long as it's below the lowest water line and the correct size

mroberts5

I've seen from what can tell are two variations of counterpitch piping. Do I have this right and is there a preference?

A- The drip is at the end of the main and the header comes down into the tee.
B- the drip drops from just before the end of the main and the header comes up into an elbow at the end of the main.

Also, my contractor is agreeing to repipe but is suggesting to install a F&T trap on the drip. This isn't necessary, correct?

Thanks.

Jamie Hall

As long as the drip ties in below the water line (I prefer the wet return) it doesn't need any traps.

mroberts5

Fixed. Much better. thanks for everyones help.

Fred

Wow, what is going on with that Near boiler piping? a couple pictures from a different angle would help us see what is going on there.

Fred

Ok, I see from an earlier picture, before the insulation how it is piped.