magnehelic connections to Enviro Mini fire box

[jamesdjs]

Well I received in my Dwyer gauge the other day and I want to check the vacuum draw in the fire box. Ran into a little problem.
Enviro already made an access hole into the fire box but its 3mm or 0.118". A 1/8" hole is 0.125"
Where do I find a 3mm copper or steel tube that is small enough to fit into the hole to measure?
I've already checked different hardware store to no avail.
Graingers only carried 1/8" tube.

Do I drill the hole out to 1/8" OD?

Inquiring minds like to know hh:

Thanks

 

[DAKSY]

Don't drill it - REAM it to .125.
You're only taking .0034 on a side.
That's too little for a drill, but perfect for a reamer &
you'll end up with a cleaner finish...

 

[jamesdjs]

Don't drill it - REAM it to .125.
You're only taking .0034 on a side.
That's too little for a drill, but perfect for a reamer &
you'll end up with a cleaner finish...

Thanks for the thought. I'm hoping to get away without reaming it out but I may have to unless someone else can come up
with another suggestion.

 

[LI-Mini-Owner]

Hi - I ran into a similar problem when I got a magnehelic for my Enviro Mini. I was able to get a stable reading by taking the rubber hose end (with a nice square cut) and holding it over the hole. A small film of silicone grease on the end might help.

This reading was the same as I got when I installed a "T" in line with the vacuum safety switch. If you take readings often you can leave the "T" in place, route the hose for the magnehelic out the back of the enclose and keep it plugged when not in use.

Carl

 

[jamesdjs]

Hi - I ran into a similar problem when I got a magnehelic for my Enviro Mini. I was able to get a stable reading by taking the rubber hose end (with a nice square cut) and holding it over the hole. A small film of silicone grease on the end might help.

This reading was the same as I got when I installed a "T" in line with the vacuum safety switch. If you take readings often you can leave the "T" in place, route the hose for the magnehelic out the back of the enclose and keep it plugged when not in use.

Carl

According to the Enviro manuals the reading on the vacuum switch will be higher than the one in the firebox.
and in order to correctley set the damper you need the value from the fire box but you say you got the same reading in both places... interesting.

 

[LI-Mini-Owner]

Hi - I ran into a similar problem when I got a magnehelic for my Enviro Mini. I was able to get a stable reading by taking the rubber hose end (with a nice square cut) and holding it over the hole. A small film of silicone grease on the end might help.

This reading was the same as I got when I installed a "T" in line with the vacuum safety switch. If you take readings often you can leave the "T" in place, route the hose for the magnehelic out the back of the enclose and keep it plugged when not in use.

Carl

According to the Enviro manuals the reading on the vacuum switch will be higher than the one in the firebox.
and in order to correctley set the damper you need the value from the fire box but you say you got the same reading in both places... interesting.

Thanks James - I'm gonna double check and compare the readings from the two locations - hopefully not until October

 

[jamesdjs]

Well I received in my Dwyer gauge the other day and I want to check the vacuum draw in the fire box. Ran into a little problem.
Enviro already made an access hole into the fire box but its 3mm or 0.118". A 1/8" hole is 0.125"
Where do I find a 3mm copper or steel tube that is small enough to fit into the hole to measure?
I've already checked different hardware store to no avail.
Graingers only carried 1/8" tube.

Do I drill the hole out to 1/8" OD?

Inquiring minds like to know hh:

Thanks

I finally got all the fittings, tubing and the hardest item to find was 1/8" copper tubing.
I found that the hole in the Enviro is already large enough to place the 1/8" copper tubing into it :cheese:
I called all the hardware place and nobody carried the 1/8" tubing unless I wanted a 50' roll..not.
Finally saw a website that had it in 12" lenghts and it turned out to be a hobby store. So I called my local hobby store and they had it in stock either copper or stainless steel.
Now all I have to do is wait for it to get cold enough to fire the stove up and set my damper. :coolsmile:

 

[smwilliamson]

Hi - I ran into a similar problem when I got a magnehelic for my Enviro Mini. I was able to get a stable reading by taking the rubber hose end (with a nice square cut) and holding it over the hole. A small film of silicone grease on the end might help.

This reading was the same as I got when I installed a "T" in line with the vacuum safety switch. If you take readings often you can leave the "T" in place, route the hose for the magnehelic out the back of the enclose and keep it plugged when not in use.

Carl

According to the Enviro manuals the reading on the vacuum switch will be higher than the one in the firebox.
and in order to correctley set the damper you need the value from the fire box but you say you got the same reading in both places... interesting.

Thanks James - I'm gonna double check and compare the readings from the two locations - hopefully not until October

Yes, the switch is after the heat exchanger and so the air is cooler. The recommendations are for readings during a high heat setting. You can see the needle drop as the fire increases in heat. Also, the switch is post the damper...though I haven't really played with differential pressure reading pre and post the damper.

 

[jamesdjs]

Hi - I ran into a similar problem when I got a magnehelic for my Enviro Mini. I was able to get a stable reading by taking the rubber hose end (with a nice square cut) and holding it over the hole. A small film of silicone grease on the end might help.

This reading was the same as I got when I installed a "T" in line with the vacuum safety switch. If you take readings often you can leave the "T" in place, route the hose for the magnehelic out the back of the enclose and keep it plugged when not in use.

Carl

According to the Enviro manuals the reading on the vacuum switch will be higher than the one in the firebox.
and in order to correctley set the damper you need the value from the fire box but you say you got the same reading in both places... interesting.

Thanks James - I'm gonna double check and compare the readings from the two locations - hopefully not until October

Yes, the switch is after the heat exchanger and so the air is cooler. The recommendations are for readings during a high heat setting. You can see the needle drop as the fire increases in heat. Also, the switch is post the damper...though I haven't really played with differential pressure reading pre and post the damper.

From the Enviro manual they say the stove has to be running on high heat and the stove should of been running for 30 minutes before checking the air draw and setting the damper.

 

[jtakeman]

Make sure the stove is at full temp. 30 minutes wasn't enough for my Omega. I would give it an hour just to be sure its at max temp. I set mine right in the middle of the range, But later went to just under the max setting. Set up your high burn setting. Then set the stove to low burn and measure what it has for a reading. Log it for a down the road reference. Its harder to set on the low burn, But it is possible if needed. If you notice rich condition on low burn. You can increase the low burn damper setting.

This is why Enviro upgraded the control with a feed rate trim and combustion blower trim. Easier to do than mess with the damper settings. see this thread for reference:

https://www.hearth.com/econtent/index.php/forums/viewthread/51337/

 

[jamesdjs]

Make sure the stove is at full temp. 30 minutes wasn't enough for my Omega. I would give it an hour just to be sure its at max temp. I set mine right in the middle of the range, But later went to just under the max setting. Set up your high burn setting. Then set the stove to low burn and measure what it has for a reading. Log it for a down the road reference. Its harder to set on the low burn, But it is possible if needed. If you notice rich condition on low burn. You can increase the low burn damper setting.

This is why Enviro upgraded the control with a feed rate trim and combustion blower trim. Easier to do than mess with the damper settings. see this thread for reference:

https://www.hearth.com/econtent/index.php/forums/viewthread/51337/

Enviro wants $298 for the new control bd that I don't have on mine.
I'll take a reading at 30 min and 1 hr and see what the difference is then set the damper.

 

[hearthtools]

I can see were some people would have a hard time finding something
I removed the core and use the outer tube of a used gas stove thermocouple as an adapt.

 

[jamesdjs]

I can see were some people would have a hard time finding something
I removed the core and use the outer tube of a used gas stove thermocouple as an adapt.

That's a good idea. Wish I had thought of that before I searched all over for a 1/8" tube.

 

[hoverfly]

[/quote]
Enviro wants $298 for the new control bd that I don't have on mine.
[/quote]


I think Enviro should give us a discount for those who all ready own a Mini.

 

[jamesdjs]

Enviro wants $298 for the new control bd that I don't have on mine.
[/quote]


I think Enviro should give us a discount for those who all ready own a Mini.[/quote]

I second that vote but I don't think its going to happen.