Manometer Draft Check Duration

I am going to be checking my draft through a hole in the side of the stove body. I have a cone shaped threaded brass cylinder (came with Dwyer) that I was going to stick into the stove to read the draft on a Dwyer Mark II manometer. Does the connector only need to clear the inside of the stove body or does it need to be inside the stove by a certain amount? Also since I am planning on using the plastic hoseing that came with the Dwyer to connect to the other end of the cone cylinder for the reading, how long does it take to get a reading on the manometer? -- I am hoping less than the amount of time it would take for the hose to start melting. Thanks

Of course, After you level it and calibrate it first.

Doesn't take that long, as soon as you hook it up, it will start to draw the liquid up on the manometer for a reading.
Should not be more than a few seconds.

Thanks Dave, definitely on level and calibrate. The calibration knob had me a little perplexed, I guess it will make sense after I start to pour the dye in but do you start with the knob all the way to the left/right prior to filling and then adjust until it reads zero?

Read the directions....You turn it all the way in, then back it out like full 3 turns, I think that is about center.

THEN, CAREFULLY (experience talking), put ONLY a LITTLE bit of red oil in at a time and watch the level carefully until it start to get close to the zero.

Once it is close, you can ZERO it out (rotate in or out) with the calibration knob to get it up to Zero.

Hook up your tube and check the level. You only need it hooked to one Side, I think the "HI" Side.

The hose is silicone, it should take some serious heat to melt it. Since you are going into the firebox you will be checking overfire draft, not chimney draft. Keep in mind, they are not always the same thing.

My Dwyer accomodates at least a full 10 turns.

hum, the manufacturer's recommendation is for overfire (.03). Is it safe to say that adjusting the baro to the setting that gets me to .03 over fire will get me to where I need to be with the baro?

Okay, turn it all the way out, counting the turns, and then turn it in 5 turns, about 1/2 way, that will get you in the middle to be able to zero it out (calibrate it).

Yes, over fire MAY be slightly different then your pipe, but either will get you close enough to calibrate your baro correctly.

The hose may be silicone, but mine melted lickity split. It may last long enough to get a reading, but more than a minute or two & splechk, it's goopsville. I came off the brass fitting with a short piece of copper tubing.

Did anyone mention CAREFULLY (experience talking), put ONLY a LITTLE bit of red oil in at a time and watch the level carefully until it starts to get close to the zero.

It's easy to add more, but a son of bituminous to get some out.

The "low" is the proper one. High is for pressure, low is for vacuum. It only needs one hose hooked up, you can leave the other as is.

It doesn't matter which one to hook it up, it will just read Positive or Negative on the scale and depending on how you want to read it. I read mine on the Positive side (right). even though I know it's a vacuum and is read as minus.

Freddy wrote:The hose may be silicone, but mine melted lickity split. It may last long enough to get a reading, but more than a minute or two & splechk, it's goopsville. I came off the brass fitting with a short piece of copper tubing.

What are your stack temps Freddy, mine are max 350* or so measured in the pipe 8" from the boiler. The silicon hose has been in place since November with no melting... so I'm wondering how come yours is running so hot???

csstoker wrote:hum, the manufacturer's recommendation is for overfire (.03). Is it safe to say that adjusting the baro to the setting that gets me to .03 over fire will get me to where I need to be with the baro?

Overfire and stack pressure reading should be done separately. To measure the draft for baro adjustment you really should measure in the pipe after the burning appliance and before the baro. Overfire adjustments are made to the combustion air (either the inlet flapper over the fan or by rheostat to control combsution fan speed). While the overfire pressure will change with respect to stack pressure IMO the whole reason for checking one Vs the other is to get the baro Vs combustion air adjustments set independently.

my combustion fan speed is fixed regardless of my feed rate. I cannot adjust it. The only thing I can do is control exhaust via the baro.

I installed the mano and went for the low side (vacuum) since this is my first time and it gave me a little more to work with in terms of precision reading the findings, but I did find that either side works as long as you know what you are reading. I am wondering if I tapped into a weird place- somewhere between the push of the combustion air and the draw of the exhaust? Although, it is in the firebox down near the exhaust outlet, I am getting a .015 vacuum reading but question the reading since I am not getting any CO or explosion issues which I thought were common with insufficient draft. Also the baro is at the factory set at .06 and I do not have any ash buildup clogging the exhaust. Should where you read in the box make a difference (directly inside the box or further in)?

csstoker wrote:my combustion fan speed is fixed regardless of my feed rate. I cannot adjust it. The only thing I can do is control exhaust via the baro.
I installed the mano and went for the low side (vacuum) since this is my first time and it gave me a little more to work with in terms of precision reading the findings, but I did find that either side works as long as you know what you are reading. I am wondering if I tapped into a weird place- somewhere between the push of the combustion air and the draw of the exhaust? Although, it is in the firebox down near the exhaust outlet, I am getting a .015 vacuum reading but question the reading since I am not getting any CO or explosion issues which I thought were common with insufficient draft. Also the baro is at the factory set at .06 and I do not have any ash buildup clogging the exhaust. Should where you read in the box make a difference (directly inside the box or further in)?

Is your choice what you do, but what I was saying is that measuring the inside of the stove Vs the pipe are apples and oranges. You can adjust the overfire pressure by putting tape or an adjustable cover over the combustion fan (adjusting speed is the other way).

Whether you are inside the front of the stove or inside directly adjacent to the flue exit can make some difference. Again this is why you should measure both the flue pipe and the stove overfire pressure. Bottom line is that you aren't having any issues with sulpher smell and your overfire pressure is negative... so other than not being able to tell the draft inside the flue pipe, what you are doing will work just fine.