vent damper question. Does it have to go vertical right off the top of the boiler?

PeteA

The crown boiler has an inline automatic vent damper that comes with the kit. Every picture in their manual shows the vent damper sitting right on top of the exhaust outlet of the boiler.
My problem is if I put it in that spot then sit a 90 on top of it I will come in too high to make it into the existing chimney opening with the nice 5 inch sleeve I'm reducing down to catch the 4" vent. But if I put a short straight piece then the 90 and then the vent damper I can make it the rest of the way to the chimney with a straight piece and have some upwards pitch which would obviously work best for me, but again the drawings all show the vent damper right on top.
To me it shouldn't really matter since the roll out switch and fresh air draft intake is well below this part. Hopefully the pictures explain better at what I am thinking.

Steamhead

Been there, done that. It'll work fine horizontally. Make sure you position the drive motor so it is on either side of the damper- NOT on the top or bottom. This should be covered in the manual for the damper.

PeteA

Thanks @Steamhead
I appreciate you getting back to me. I'll make sure that the motor/shaft is not towards the top or bottom.
I've seen in many videos these inline ones horizontal in the vent pipe but I wanted a sanity check in case that was a no no.

EBEBRATT-Ed

The boiler manual specifically states the damper is supposed to be mounted directly on the flue collector. You have plenty of room to make a new hole in the chimney and patch the old. This would have been better off found before the boiler was set and piped for easier access to the chimney.

Also. When the flue pipe comes off the boiler straight up that is called "self venting" , Any riser in the flue pipe should be at the boiler so it vents properly.

By putting an elbow on the boiler you are reducing the boilers vent capacity

EdTheHeaterMan

I also have done that. but @EBEBRATT-Ed is correct about having some riser on the draft hood before the first elbow. Mounting the damper on the draft hood sort of guarantees that there is a 6" riser direcly off the vent hood. I would cut a 4" (6" including the crimp) riser on yours as long as there is a 1/4" per foot rise in the horizontal pipe.

That boiler does not need a vent damper to operate safely. It only needs it to operate efficiently enough to pass the certification process for the minimum efficiency government regulations. Placing it on the horizontal will not compromise the safety, It may however be an issue if there is ever a problem with home damage as a result of the boiler operation. If it ain't like the instructions say, then it goes back to the installer who done it. Are you properly insured?

Or as it says on some contractors trucks "Fully Insured".

I have always been partial to "partially insured". (that was a PUN)
I have never used the "not insured". But they don't put that on there trucks

I have seen those that are "Licensed and Insured"
While others are "Fully Licensed and insured"

Does that mean they are Fully licensed and partly insured?
Are the other guys only partly licensed and partly insured?
I think that if they are fully licensed and fully insured, they should say so on the truck.

Unless they pay for the lettering on the truck by the letter. That would add to the cost of the truck and make my price go up.

Am I starting to sound like George Carlin? RIP. Sorry! I'll shut up now.

PeteA

Thanks @EBEBRATT-Ed but do you feel that I'm really losing that much draft? I only ask because I was thinking that a short straight piece to the 90 to the damper is actually taller than the damper itself but not too tall as putting the 90 on top of the damper is. Just **** to blow out the cemenet and brick to gain a couple of inches.
The old boiler was much bigger and had nearly zero pitch to the vent and had an elbow immediately out of the top but it did NOT have any type of damper so I was really hoping to do something similar. Here is the old vs the new. There would be a small straight piece under the elbow, just not sure how tall yet.

PeteA

Thanks @EdTheHeaterMan
That's exactly what I would probably end up with which is a few additional inches below the 90 with a small straight piece added but enough to maintain a slight upwards pitch since the fireplace and the unit is close together. But if worst comes to worst I'll have to pick up some brick and mortar

EdTheHeaterMan

PeteA said:

Thanks @EdTheHeaterMan
That's exactly what I would probably end up with which is a few additional inches below the 90 with a small straight piece added but enough to maintain a slight upwards pitch since the fireplace and the unit is close together. But if worst comes to worst I'll have to pick up some brick and mortar

Will you get that stuff online or pick it up at a brick and mortar store?

Sorry, I couldn't help myself

PeteA

good to know folks still have a sense of humor
really appreciate the info @EdTheHeaterMan

Steamhead

Well, I've never seen a boiler manual that says NOT to move the damper to a horizontal position. If there is such a thing out there, I'd appreciate seeing it.

If a building is old enough to have gravity hot-water heat, it's also old enough to have had a coal-fired boiler. Chimneys used with coal boilers had to develop a lot of draft to pull air through the bed of coal on the grate. Some of these chimneys could probably pull pets and small children up to the roof. This level of draft is way too much for oil or gas burners, which is why we have draft hoods and barometric draft regulators.

Perhaps this explains why, when we see an elbow on top of a draft hood, there's never a drafting issue. If there was, the combustion test would reveal it.

EBEBRATT-Ed

I would say it comes down to this.

1. Put the damper horizontal and be done with it. Will it work? Yes Will it ever be a problem? probably not.

2. Put the damper vertical and chop out the chimney. More work


On this forum we try and do thing right and follow the MFG instructions. You have to draw the line somewhere.

Where do you draw the line?? When do you let something cross the line and when do you not cross the line?

If it was impossible to raise the flue opening maybe that would be a reason to put the damper horizontal although it still wouldn't make it right.

In this case I think about sitting before a judge. Why didn't you raise the flue opening in the chimney? Answer: Because I didn't want to. The extra labor was 2 hours including doing the extra work and picking up the material and cleaning up and the material cost was $50

Steamhead

EBEBRATT-Ed said:

On this forum we try and do thing right and follow the MFG instructions. You have to draw the line somewhere.

Where do you draw the line?? When do you let something cross the line and when do you not cross the line?

If the manufacturer's instructions said to not mount the damper horizontally, obviously I would not. But I have never seen a specific prohibition of this.

One example of a specific prohibition is found in the attached Dunkirk piping diagram. It specifically states that the steam riser and header be 2-1/2". How many times have we seen this reduced to 2"? Personally, I've repiped several such boilers to spec because it does make a difference, and obviously that's why the manual so states.

EdTheHeaterMan

Steamhead said:

Well, I've never seen a boiler manual that says NOT to move the damper to a horizontal position. If there is such a thing out there, I'd appreciate seeing it.

If a building is old enough to have gravity hot-water heat, it's also old enough to have had a coal-fired boiler. Chimneys used with coal boilers had to develop a lot of draft to pull air through the bed of coal on the grate. Some of these chimneys could probably pull pets and small children up to the roof. This level of draft is way too much for oil or gas burners, which is why we have draft hoods and barometric draft regulators.

Perhaps this explains why, when we see an elbow on top of a draft hood, there's never a drafting issue. If there was, the combustion test would reveal it.

I saw that movie when I was a little boy! I think one of those chimneys actually pulled Dic k VanDyke up to the roof.

EdTheHeaterMan

I just read the manufacturers venting instructions. On page 15 item 14-C states

"Mount the vent damper on the flue collar without modification to either and secure with sheet metal screws. Make sure screws do not interfere with damper blade operation. Vent damper blade position indicator must be visible to users."

But I agree with @EBEBRATT-Ed and believe that there are too many lawyers to worry about a moving a couple of bricks. Do the higher hole!

Here is the link to the instructions. You can look at page 15 yourself, then decide:
https://www.velocityboilerworks.com/documents/9807815-Rev-C-6-22-Aruba-5.1-IOM.pdf

Steamhead

In that case, I'd first call the manufacturer to see if they'd allow a horizontal installation. There are some situations where you just can't get the extra height.

PeteA

@EdTheHeaterMan @Steamhead @EBEBRATT-Ed
First of all thank you all for helping me with this. I really appreciate the feedback and the input from you folks and I'm hoping this question isn't making any bad blood between each of you. I am certainly not looking to violate any laws or rules but I'm just picking the brains of folks like all of you that I'm sure have been in this situation more times that I'll ever be to see how they worked it out.
I did look at the manual and I now see exactly where @EdTheHeaterMan mentions the without modification line. Thanks for that. I will email with my specific situation and give them the measurements to see if they feel the 4" difference in the height to the top of the 90 elbow is an issue to horizontally mounting the damper.
I would have 10 1/2 inches to the top of the 90 with the vent damper horizontal and just about 14 1/4 with the damper before the 90.
I'll let you all know if they give me the thumbs up or if I'm doing some brick and mortar work. The chimney sucks like a vacuum so maybe I'll try and get a draft reading for them to also consider.

JohnNY

Throw that thing in the garbage and jump it out on the harness.
Done.

Steamhead

PeteA said:

........ The chimney sucks like a vacuum so maybe I'll try and get a draft reading for them to also consider.

Just keep pets and small children away from it!

Steamhead

JohnNY said:

Throw that thing in the garbage and jump it out on the harness.
Done.

I happen to like vent dampers. In addition to keeping the boiler from cooling down so quickly between firing cycles, they also reduce air infiltration into the building. Since a warm chimney will continue to pull draft after the burner shuts off, the closing damper prevents air entering the chimney which must then be replaced by cold air from outside.

It's true some of the early dampers were unreliable, but Field makes a good, reliable unit now. Plus, if it does break down, they make replacement drive motors available (part# GVD-RMA) so fixing one takes less than an hour. Every service truck should have one. Ours do.

I once had a call from a lady who had recently bought a house that came with a home warranty. The boiler wasn't working and the warranty company's "tech" diagnosed a failed damper motor, and told her it would take two weeks to get one. I went there, replaced the motor, tested it per instructions, and she had heat. Simple.

EdTheHeaterMan

JohnNY said:

Throw that thing in the garbage and jump it out on the harness.
Done.

One thing to be awair of on that Vent Damper Plug. Most if not All controls that have that vent damper plug have a feature that once a damper is employed on a system, just unplugging the damper and placing a jumper equipped plug in its place will not work.

EBEBRATT-Ed

This is from the Crown website for the Aruba boiler which I am not sure if that is the boiler you have:


Page 14 in the manual


14) Installation of the vent damper supplied with this boiler is mandatory. Install vent damper (see Figure 6.2) as follows:
a) Open vent damper carton and remove installation instructions. Read the instructions thoroughly before proceeding.
Verify that vent damper is same size as draft diverter outlet (Figure 2.1). Unpack vent damper carefully. Do not
force closed damper blade. Forcing vent damper closed may result in damaged gear train and void warranty.
b) Vent damper is factory shipped having approximately ¾” diameter hole in the vent damper blade, which must be
plugged. Use the plug supplied with the damper.
c) Mount the vent damper ON THE FLUE COLLAE WITHOUT MODIFICATION to either and secure with sheet metal screws. Make
sure screws do not interfere with damper blade operation. Vent damper blade position indicator must be visible to
users.
d) The damper wire harness is shipped pre-wired into the boiler. Plug the loose end of this harness into the damper and
secure the flexible conduit to the damper using a connector nut provided.
Provide adequate clearance to combustible construction and servicing.
e) Install vent connector pipe and vent fittings from vent damper outlet to chimney or gas vent. Secure with sheet metal
screws and support as required.

jesmed1

Steamhead said:

It's true some of the early dampers were unreliable, but Field makes a good, reliable unit now. Plus, if it does break down, they make replacement drive motors available (part# GVD-RMA) so fixing one takes less than an hour. Every service truck should have one. Ours do.

That's good to know. I had considered installing Field oil vent dampers on our oil boilers, but I was on the fence because some reviewers said they were unreliable. I guess the thing to do is have a spare motor on hand in case a quick fix is needed, because if they crap out, the boiler won't come one.

Maybe I'll try one out this winter.

realliveplumber

Make that hole for the boiler flue a clean out, open up the hole for the water heater and add a 5-5-4 wye.

That chimney probably needs a liner anyway.

ChrisJ

I moved mine on an EG40 away from the boiler just because I was tired of the draft hood cooking the motor.

PeteA

@EBEBRATT-Ed @Steamhead @EdTheHeaterMan @JohnNY
JohnNY
The good news is that I didn't have to just throw it away and install some type of a jumper although that was a pretty tempting idea

I heard back from velocity boiler works and based on the info that I provided them, they referred me to the manufacturer of the vents installation manual which says it can be mounted horizontally or vertically.

The only concern Velocity had was that the harness came prewired for the damper and that it may not reach. I explained to the tech that even with the small straight piece riser below the 90 and with the damper now horizontal that the wiring harness still reached the controls without any modifications. I also told them I would be able to maintain the correct orientation of the shaft as shown in the manual also.

So I'm good to go with the install. I printed the email for my records and so far so good. Good pitch to the vent and no brick and mortar work at this point.

Thanks for everyones input on this one seems like such a small thing but like everyone said earlier it should either be done right or refer to the manufacturer.

Pete

Steamhead

jesmed1 said:

Steamhead said:

It's true some of the early dampers were unreliable, but Field makes a good, reliable unit now. Plus, if it does break down, they make replacement drive motors available (part# GVD-RMA) so fixing one takes less than an hour. Every service truck should have one. Ours do.

That's good to know. I had considered installing Field oil vent dampers on our oil boilers, but I was on the fence because some reviewers said they were unreliable. I guess the thing to do is have a spare motor on hand in case a quick fix is needed, because if they crap out, the boiler won't come one.

Maybe I'll try one out this winter.

I don't think Field markets a replacement motor for their oil vent dampers. Never seen one for sale, and Google came up empty.

EdTheHeaterMan

The Tech Guys at Velocity Boiler Works (Crown) are good. They have actually worked on heaters in an earlier life. Bob used to work for my Father's company and John has always been a wealth of knowledge for me when I was out there working.

PeteA

@EdTheHeaterMan
I am sure they are on top of their stuff. I was actually impressed with the quick turnaround of an answer to my question. That all by itself is becoming incredibly rare to find.
I really appreciate your feedback on this. I do try to do stuff the right way all the time and ask lots of questions from folks like yourself when I'm hitting a wall.

jesmed1

Steamhead said:

I don't think Field markets a replacement motor for their oil vent dampers. Never seen one for sale, and Google came up empty.

I think this is the correct replacement motor for the Fields oil vent damper (OVD) series:

https://www.supplyhouse.com/Field-Controls-46564000-Replacement-Motor-Assembly-Aluminum-Base-for-OVD-Series