Monometer Questions

[edrobyn]

I think that I have a bunch of heat going up my chimney so I bought a Drwyer Monometer to check the draft. I have a 6" flue pipe with a manual damper about 12" above the wood stove. Do I check when the stove is hot or cold? Do I drill a hole in the pipe for the tube? Is it ok to drill a hole in the flue pipe without smoke coming out of it? How far up the pipe do I drill the hole? How do I use the tube in a hot pipe with melting the tube?

 

[brenndatomu]

First off, what are you running here, stove, furnace? Model?

Do I check when the stove is hot or cold?

Hot. Get a good fire going for 10-15 minutes or so, you want the chimney to be up to temp

Do I drill a hole in the pipe for the tube?

Yes

Is it ok to drill a hole in the flue pipe without smoke coming out of it?

Smoke won't come out unless you have some real (low) draft problems

How far up the pipe do I drill the hole?

You have a straight shot to the chimney or elbows? If you have elbows just stay away from them, you want to be in the middle of a nice straight run of pipe

How do I use the tube in a hot pipe with melting the tube?

You need to get a 1' long piece of metal tubing that that rubber tube will fit in, or over. Bend the tubing into an S shape and hang it from the hole that you just drilled in the pipe. The hole should be just big enough to get the tubing in

 

[maple1]

And if you have any pipe dampers, do the measuring between the damper & stove.

 

[SidecarFlip]

Not to nitpick but it's a manometer and it's Dwyer

 

[velvetfoot]

I bought a digital manometer on EBay for cheap and it seems to work fine.
Your appliance may already have a hole in its flue to check draft-my BioWin does.

 

[edrobyn]

You need to get a 1' long piece of metal tubing that that rubber tube will fit in, or over. Bend the tubing into an S shape and hang it from the hole that you just drilled in the pipe. The hole should be just big enough to get the tubing in

So the end of the metal tube shaped like an "S" that is hanging inside the flue would be parellel facing down toward the draft or does the metal tube need to be more like a "Z" and the end be perpendicular to the draft?

Thanks for the replies(and the correction) it is manometer and Dwyer. I do have a straight run of pipe to drill into above the stove and it is an Englander 28-3500.

 

[brenndatomu]

So the end of the metal tube shaped like an "S" that is hanging inside the flue would be parellel facing down toward the draft or does the metal tube need to be more like a "Z" and the end be perpendicular to the draft?

I've done both ways and it didn't seem to make any difference

 

[maple1]

My metal tube is straight, I didn't bother with bends. Just sticks straight in. I just picked a brake line out of a bin at the auto parts place that would fit inside the manometer tube. It's a bit over a foot long, and the fittings it had on the one end allowed me to use them to hold it in place in the pipe.

 

[brenndatomu]

I didn't bother with bends. Just sticks straight in.

That's true, I'm sure there are many different ways of doing it, the S shape just worked well for me. Brake line is a good idea though!

 

[velvetfoot]

I bought a right angle probe with a magnet on it to keep it on the pipe. Never used it though.

 

[trx250r87]

My flue is 27' tall and I have too much draft. I installed a manual damper at the 6" rear output of my furnace. The manometer probe is about 2' above the damper in double wall black pipe. I get about .14" IWC when damper is open and the number seems to increase as I close the damper. Is this because the manometer probe should be after/above the manual damper?

Eric

 

[brenndatomu]

My flue is 27' tall and I have too much draft. I installed a manual damper at the 6" rear output of my furnace. The manometer probe is about 2' above the damper in double wall black pipe. I get about .14" IWC when damper is open and the number seems to increase as I close the damper. Is this because the manometer probe should be after/above the manual damper?

Eric

You should have the probe between the furnace and any flue damper. Draft will drop as you close the damper, or drop as the air door opens with a barometric draft regulator

 

[maple1]

My flue is 27' tall and I have too much draft. I installed a manual damper at the 6" rear output of my furnace. The manometer probe is about 2' above the damper in double wall black pipe. I get about .14" IWC when damper is open and the number seems to increase as I close the damper. Is this because the manometer probe should be after/above the manual damper?

Eric

Ya, your manometer is hooked into the wrong spot. Or the damper is. They need to switch spots in the exhaust stream, anyway.

 

[brenndatomu]

Ya, your manometer is hooked into the wrong spot. Or the damper is. They need to switch spots in the exhaust stream, anyway.

Yeah, I missed that detail...at, damper should be a couple feet away from the furnace, not at, and then take your draft sample in between, preferably toward the middle of that span if it is a straight section of pipe

 

[Sparky]

Yeah, I missed that detail...at, damper should be a couple feet away from the furnace, not at, and then take your draft sample in between, preferably toward the middle of that span if it is a straight section of pipe

I got a Dwyer Mark II model 25 filled it with fluid have it mounted level on the wall. Now it has 2 tubes and two brass fittings? Directions are for a hot air plenum? Not sure how to use it? Any help would be appreciated. Thanks

 

[maple1]

Get it reading exactly zero with no tubes hooked to it. Then hook the tube/pipe setup you have in your flue, to the 'low' fitting on the top of the Dwyer. Leave the 'high' fitting open, not hooked to anything. Then read chimney draft - fluid should slowly rise up the gradually sloped tube to the right side of the Dwyer, and stop when it gets to measured draft reading.

 

[Sparky]

Get it reading exactly zero with no tubes hooked to it. Then hook the tube/pipe setup you have in your flue, to the 'low' fitting on the top of the Dwyer. Leave the 'high' fitting open, not hooked to anything. Then read chimney draft - fluid should slowly rise up the gradually sloped tube to the right side of the Dwyer, and stop when it gets to measured draft reading.

OK I did that and now it is measuring around -.03 I believe that is where econoburn recommends it?

 

[maple1]

Not sure what Econoburn recommends.

That reading is with a normal fire burning?

 

[Sparky]

Yes up to temp and they want -.02 / -.05 I couldn't get that reading at first, the adjustment wouldn't go up that far so instead of adding another barometric damper I added weights (washers) and it seems to be working??