Dwyer Mark II Question

Good evening my fellow board members,

I may have an odd one, but here goes, I moved the Dwyer Manomometer from the flue pipe
end of the stoker and mounted it on the door that we never use. The Pitot tube is inserted in the hole in the fire inspection door as its supposed to be. I may not keep it there when running the stoker but the issue is the liquid level.

I made sure the meter was level had its preliminary adjustment and then I filled the fluid reservoir chamber,
soaked up any excess fluid according to the directions with a pipe cleaner to bring it to Zero and now the red fluid is two marks past "0" to the positive.

I did not look at the Dwyer Mark II Manomometer while the boiler was running on oil today but I will this weekend when I have time.

Any thoughts? we have had high pressure/mostly clear air/blue sky all day so that may be an issue.

I have to look at the instruction sheet again to see if it mentions anything like this.

Thanks much,

Leon

lzaharis wrote:Good evening my fellow board members,

I may have an odd one, but here goes, I moved the Dwyer Manomometer from the flue pipe
end of the stoker and mounted it on the door that we never use. The Pitot tube is inserted in the hole in the fire inspection door as its supposed to be. I may not keep it there when running the stoker but the issue is the liquid level.

I made sure the meter was level had its preliminary adjustment and then I filled the fluid reservoir chamber,
soaked up any excess fluid according to the directions with a pipe cleaner to bring it to Zero and now the red fluid is two marks past "0" to the positive.

I did not look at the Dwyer Mark II Manomometer while the boiler was running on oil today but I will this weekend when I have time.

Any thoughts? we have had high pressure/mostly clear air/blue sky all day so that may be an issue.

I have to look at the instruction sheet again to see if it mentions anything like this.

Thanks much,

Leon

Was the Stoker run recently ? If it was, than any heat left in the stoker and the chimney are likely still be warm enough to cause that much draft even if the stoker is not running. Any stove and chimney system will do much the same show of draft.

My stove pipe mounted Dwyer Mark II shows about .005 reading in mid summer long after the range has been out. It's just showing the natural draft of the very tall chimney the stove is hooked up to.

Plus, on windy days the readings will move up and down without any heat from the stove as the wind pressure changes the air pressure inside the house. And just wind blowing across the top of a chimney can cause pressure difference inside the chimney and stove.

Paul

The meter must be zeroed every time you use it. Just the nature of the beast.

Disconnect the mano tube and tweak the knob so it reads zero then reconnect the tube. If it's showing a reading without a fire burning that just means the chimney is creating some draft. The draft could be caused from a number of things such as - the chimney is warmer or cooler than the ambient air - wind is blowing across the chimney top - something causing a pressure difference in the house (such as an exhaust fan)

Atmospheric barometric pressure wouldn't have any influence by itself.

Lightning wrote:Disconnect the mano tube and tweak the knob so it reads zero then reconnect the tube. If it's showing a reading without a fire burning that just means the chimney is creating some draft. The draft could be caused from a number of things such as - the chimney is warmer or cooler than the ambient air - wind is blowing across the chimney top - something causing a pressure difference in the house (such as an exhaust fan)

Atmospheric barometric pressure wouldn't have any influence by itself.

I think he did that already Lee,.... he's wondering why after moving it refilling and re-zeroing it it's reading two marks up.

"I made sure the meter was level had its preliminary adjustment and then I filled the fluid reservoir chamber,
soaked up any excess fluid according to the directions with a pipe cleaner to bring it to Zero and now the red fluid is two marks past "0" to the positive. "

If it's not residual heat in stove/chimney system, he's got a really good drafting chimney with just the temp difference between basement and outdoors.

Paul

Right, I saw that. I just wanted to rule out any settling of the fluid that may have occurred.

Here's a neat link of me doing draft tests on a sleeping chimney.

Chimney Draft Test

Thanks for responding to my inquiry.

I will say that with the new high temperature fiberglass insulation sheet I bought
from Mcmaster Carr and laid on the boiler is a massive heat blanket and the boiler
hold the oil heat in for long time.

The warm chimney and boiler bleeding heat out the stack past the welded baffle plate on the
flue breech makes sense. The added 3 feet of the stainless steel extension I bought from
Rockford Chimney supply and had installed three years ago would only increase the
natural draft by "so" much.

I am tempted to experiment with smaller G.P.H. oil nozzle now but I will wait a bit before
I make that decision.

The hanging baffle helps to keep the flame under the steam chest in a very small area
above the stoker.

Let me get this strait, you moved the hose to the manometer from the stoverpipe (chimney draft), to the fire door (overfire draft). The boiler is currently running on oil, not coal and you are wondering why the manometer is reading .02 (really -.02).

The answer is, that is about what it should read. Your boiler has heat inside it and it is keeping the chimney warm, like it should. The overfire draft on my boilers is between -.01 and -.03 when just sitting.

And don't forget; when you are running it on coal, the overfire draft is more important than the chimney draft. I would keep than mano reading the overfire draft.

-Don

StokerDon wrote:Let me get this strait, you moved the hose to the manometer from the stoverpipe (chimney draft), to the fire door (overfire draft). The boiler is currently running on oil, not coal and you are wondering why the manometer is reading .02 (really -.02).

The answer is, that is about what it should read. Your boiler has heat inside it and it is keeping the chimney warm, like it should. The overfire draft on my boilers is between -.01 and -.03 when just sitting.

And don't forget; when you are running it on coal, the overfire draft is more important than the chimney draft. I would keep than mano reading the overfire draft.

-Don

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Hello Don,

About my KAA-4-1 installation-I wrote in error saying I used the flue pipe (insert tired and late here).
I only use the Keystoker fire inspection door probe hole for the Dwyer II Manomometers Pitot Tube I do not have a Manomometer probe hole in my flue stack. I removed the Manometer hose from the Manomometer and readjusted the zero setting on the Dwyer Mark II Manomometer before I hit the rack last night and I will check it again when I start burning oil again.

I filled t he hopper last night so that the wife would not have to do it the first week of November and I am very happy that the boiler is finally doing what its supposed to do. It reminds me why pulverized coal boilers and walking grate stoker boilers use compressed air to control their combustion systems as the method is fool proof.

Leon