Enviro EF-5 Restricting Air Intake

[Jamesieboy]

Hey folks,

Bought my house in May 2015 and it came with an Enviro Evolution EF5 pellet stove (2006) - it's been quite the learning curve to say the least. Long story short, I'm finding that no matter how much I adjust settings on the control panel or adjust the damper, I've never been able to get an efficient flame (it has never even been close to what's advertised as an efficient flame in the manual), and therefore, heat production isn't where I feel it should be. It's always getting too much air... until today I was playing around with the stove, and I heavily restricted the air intake (doesn't have a fresh air intake installed), and the flame was perfect and was generating nice heat. It's almost like there's too much vacuum inside the stove itself, and the combustion blower is on 1 (default is 2). I could probably up the feed rate trim to the max - 5 (it's on 4, default is 4) and it might work ok, but consumption of pellets to heat produced ratio wouldn't even be worth it.

I've cleaned it thoroughly(disassembled quite a bit including the combustion blower/housing) and switched to the highest BTU pellets I have access to (hardwood).

Has anybody else had this issue, or any experience with this?

Thanks in advance!

 

[Emich]

Hey folks,

Bought my house in May 2015 and it came with an Enviro Evolution EF5 pellet stove (2006) - it's been quite the learning curve to say the least. Long story short, I'm finding that no matter how much I adjust settings on the control panel or adjust the damper, I've never been able to get an efficient flame (it has never even been close to what's advertised as an efficient flame in the manual), and therefore, heat production isn't where I feel it should be. It's always getting too much air... until today I was playing around with the stove, and I heavily restricted the air intake (doesn't have a fresh air intake installed), and the flame was perfect and was generating nice heat. It's almost like there's too much vacuum inside the stove itself, and the combustion blower is on 1 (default is 2). I could probably up the feed rate trim to the max - 5 (it's on 4, default is 4) and it might work ok, but consumption of pellets to heat produced ratio wouldn't even be worth it.

I've cleaned it thoroughly(disassembled quite a bit including the combustion blower/housing) and switched to the highest BTU pellets I have access to (hardwood).

Has anybody else had this issue, or any experience with this?

Thanks in advance!

Same here. I am getting the same heat using %30 less pellets by restricting the air intake and cleaning the burning cup from ash every 24 hours.

 

[johneh]

If you remove the combustion blower you will find
ash build-up by the damper plate which stops it from
closing all the way . You may ao find a nut on the damper
rod that stops the plate from closing all the way .
The plate can close the exhaust port off completely
if it is clean and free

 

[johneh]

Same here. I am getting the same heat using %30 less pellets by restricting the air intake and cleaning the burning cup from ash every 24 hours.

If you have to clean the burn pot you have restricted the air too much
My burn pot is clean after 10 bags when I clean my stove
I have seen ef 5 have a hopper fire because of not enough combustion air
and I will bet your glass is covered in black ash after 48 hours

 

[Jamesieboy]

If you remove the combustion blower you will find
ash build-up by the damper plate which stops it from
closing all the way . You may ao find a nut on the damper
rod that stops the plate from closing all the way .
The plate can close the exhaust port off completely
if it is clean and free

I had the combustion blower off at the start of the season, that's why I had to change out the gaskets (fan and housing). The buildup there is nowhere near enough to justify my problems. This stove is designed so you can't completely shut the exhaust down with the damper- it moves about halfway closed max - there is a built in stopper for the plate in the slide it runs in. Also, there's 2 nuts on this damper lever - inside the cover panel and out, and neither are tightened in place - they both move freely.

I put my magnehelic gauge on it, and no matter what I do, I can't change the fact that I have too much vacuum.

 

[Mt Bob]

I had the combustion blower off at the start of the season, that's why I had to change out the gaskets (fan and housing). The buildup there is nowhere near enough to justify my problems. This stove is designed so you can't completely shut the exhaust down with the damper- it moves about halfway closed max - there is a built in stopper for the plate in the slide it runs in. Also, there's 2 nuts on this damper lever - inside the cover panel and out, and neither are tightened in place - they both move freely.

I put my magnehelic gauge on it, and no matter what I do, I can't change the fact that I have too much vacuum.

View attachment 291308

Do you consider that high?

 

[johneh]

I have never seen one that the damper will not close all the way .
My shop ef5 the plate closes right across the exhaust and will smother the fire
my ef3 the same thing

 

[Jamesieboy]

Do you consider that high?

I do. The manual says .10-.11 on high fire. I can't get it below what you see in the image above.

 

[Jamesieboy]

I have never seen one that the damper will not close all the way .
My shop ef5 the plate closes right across the exhaust and will smother the fire
my ef3 the same thing

Weird. This one doesn't. I'll have to pull it apart again and see why there's a stopper there.

Since you know the ef5s, do you find a difference between softwood and hardwood pellets? The ones I used to use have rebranded and now suck - they were softwood. I'm finding I'm only having luck with hardwood this year, even with comparable BTUs.

 

[Mt Bob]

There have been rare cases of too much draft.But more cases of too little draft. Motors and impellers have been swapped to fix these. Perhaps wrong motor/impeller on yours? But, in all most all cases of too much draft, it was because of having a very tall flue. But I do remember one stove model that all had too much, and was considered a fix to partially restrict the intake. Sorry,don't remember brand or model.
As far as the reading on your gauge,I cannot say. What I got from Enviro was-
Enviro
"We do not measure static or running vent draft for pellet stoves, we have to measure draft at

the stove. Install a vacuum Tee between the vacuum switch and drop tube. Install the vacuum gauge

on the Tee. Turn thermostat on Dial Control. **Make sure hopper has fuel in it this can effect

the vacuum reading**. It takes a minimum of .04 inches of water column to close the vacuum

switch. Your vacuum gauge should be reading .19 t0.30 inches of water column while the exhaust

blower is running on high. (on a cold appliance and no fire)"

Now about where you have it set(blocked off) right now, I would say you are close, but perhaps a bit restricted, as you should be able to go 3 days before needing to scrape the pot,by the manual.
You have to remember pellet stoves waste some heat up the flue, for cleaner burning,emissions.
So I think you are close. If looks like you cannot make your damper shut all the way down,consider a "gate" for a wood shop vacuum system, you could put it on the back of stove, before the OAK tube.

 

[johneh]

I would hesitate before installing a gate on the air intake
The combustion fan will find makeup air from around the door seal
and pellet drop tube which defeats the purpose of the air intake
drawing air through the burn pot for combustion.
Something to consider

 

[Jamesieboy]

There have been rare cases of too much draft.But more cases of too little draft. Motors and impellers have been swapped to fix these. Perhaps wrong motor/impeller on yours? But, in all most all cases of too much draft, it was because of having a very tall flue. But I do remember one stove model that all had too much, and was considered a fix to partially restrict the intake. Sorry,don't remember brand or model.
As far as the reading on your gauge,I cannot say. What I got from Enviro was-
Enviro
"We do not measure static or running vent draft for pellet stoves, we have to measure draft at

the stove. Install a vacuum Tee between the vacuum switch and drop tube. Install the vacuum gauge

on the Tee. Turn thermostat on Dial Control. **Make sure hopper has fuel in it this can effect

the vacuum reading**. It takes a minimum of .04 inches of water column to close the vacuum

switch. Your vacuum gauge should be reading .19 t0.30 inches of water column while the exhaust

blower is running on high. (on a cold appliance and no fire)"

Now about where you have it set(blocked off) right now, I would say you are close, but perhaps a bit restricted, as you should be able to go 3 days before needing to scrape the pot,by the manual.
You have to remember pellet stoves waste some heat up the flue, for cleaner burning,emissions.
So I think you are close. If looks like you cannot make your damper shut all the way down,consider a "gate" for a wood shop vacuum system, you could put it on the back of stove, before the OAK tube.

Ok, that's good to know. I was taking my specs from the attached image(s), and was taking my reading from the hole just above the ash pan. I haven't restricted the air intake yet, as I need to make sure that's my last resort before I do so.

I'm so frustrated with this stove. The last 5 years, I've had no problems at all. All of a sudden, La Crete rebranded their pellets and I can't get anything to burn right. I used to be able to have the house at like, 22°C with the windows cracked on a mild day with the stove on 3 (it's not a dial-a-fire), and keep up no problem at -30C at 4 or 5 and now I'm struggling to get any kind of measurable heat from this thing. I've tried softwood and hardwood pellets, all over minimum required specs and just struggling.

I've always felt the stove has been getting more air than it should due to the flame characteristic and the lack of ability to make a lazy flame short of cracking open the door, but pellet quality has been able to keep up to it until this year.

One thing I have been wondering though, is I replaced my 3 drafty basement windows this summer, so I wondered if that was impacting the stove at all. I ran a temporary hose from the window to the air intake to see if there was a change, but there seemed to be no change.

I've got a couple more things I'd like to try, but I'm about to give up and call a tech in on this one.

I really appreciate all the input from you guys! Thanks a lot!

 

[Emich]

If you have to clean the burn pot you have restricted the air too much
My burn pot is clean after 10 bags when I clean my stove
I have seen ef 5 have a hopper fire because of not enough combustion air
and I will bet your glass is covered in black ash after 48 hours

The glass is clean. The burning is very efficient. I had to install dimmer to slow the speed of the auger motor.

 

[johneh]

I am curious! Have you read any of the tech manuals that tell you how to set
up the damper slide so that it can be adjusted from outside the cabinet?

 

[Emich]

I am curious! Have you read any of the tech manuals that tell you how to set
up the damper slide so that it can be adjusted from outside the cabinet?

There is a drag adjuster (no dumper) that can reduce the exhaust flow a little. It's useless unless you have long chimney.

 

[johneh]

I have worked on Enviro Stoves for 20 years
I have seen many that do what yours does.
In all cases, the Damper slide plate has ash in
the rails where the plate slides not allowing
the DAMPER to close
Just a suggestion CLEAN ALL OF THE STOVE
Mag. readings are just a suggestion different altitudes give different readings
Enviro factory close to Sea Level in BC Canada