Newbie Questions

[ChevyGuy]

Hi everyone,
This will be my first serious year of burning for heat. I have a 2400 s.f. carriage house behind my house that I have been renovating to be a wood shop. I have installed a Englander 28-3500 wood furnace that I bought used (Used 1 year) 2 years ago. It is installed on the first floor, on concrete, inside it's own furnace room with the required 5/8 firecode sheetrock. The chimney is 6" dbbl walled black pipe from the furnace, up through the ceiling, through the second story to just about 18" short of the ceiling, which is cathedral. From there up I have the dbble wall stainless pipe up to the required 24" above the peak that is withing 10'. All this was approved by my town fire inspector.

With that stated, I have been burning for about 2 weeks now and have excellent draft and things have been going well. Temp gauge on furnace hovering between 350 and 400 degrees and nice and warm in the shop. After slow burning all night last night I went out and through in a few pieces of wood and went back in the house. Come out an hour later and the fire is roaring big time. So much that I got nervous. I didn't have the ash tray vent open hardly at all and the built in furnace slide draft control/damper was also almost shut. Wanting to calm the fire down I shut both ash door air valve and damper totally. But it still was roaring, even 30 minutes later. The furnace temp was still around 400 and not in the red zone but I was nervous. From my limited understanding that fire should die out if those 2 things are shut close. Am I right here? It is still out there burning away (I have a guy watching it) with both valve and damper shut. What am I to think? Should I look for air leaking in? Do I need another damper in the Chimney? Your help in greatly appreciated.

 

[begreen]

It sounds like by leaving the both vents open for too long of a time the wood mass has been heated up to the point of rapid release of wood gases. Normally that the lower vent is just for startup, maybe 5-10 minutes. I suspect the furnace air control does not close completely. It admits a little air to keep a minimal fire going. If so, what is happening now is the wood gases are burning off. If draft is strong due to very cold temps, or a tall flue or both will keep the fire going strong now until the offgassing has slowed down. The blower is probably what is keeping the body temp reasonable. Just a guess, but if you had a thermometer on the flue pipe you would have noted very high temps there.

When the fire goes out check the door gasket seal to make sure that is not the issue. Do the dollar bill test at several points around the door. It should pull out firmly with some tension. How tall is the chimney that the furnace is attached to?

 

[ChevyGuy]

It sounds like by leaving the both vents open for too long of a time the wood mass has been heated up to the point of rapid release of wood gases. Normally that the lower vent is just for startup, maybe 5-10 minutes. I suspect the furnace air control does not close completely. It admits a little air to keep a minimal fire going. If so, what is happening now is the wood gases are burning off. If draft is strong due to very cold temps, or a tall flue or both will keep the fire going strong now until the offgassing has slowed down. The blower is probably what is keeping the body temp reasonable. Just a guess, but if you had a thermometer on the flue pipe you would have noted very high temps there.

When the fire goes out check the door gasket seal to make sure that is not the issue. Do the dollar bill test at several points around the door. It should pull out firmly with some tension. How tall is the chimney that the furnace is attached to?

The total chimney height is about 20'. I will do the dollar bill test as you suggested and get back to you. Are the gasses really going to burn that long? If the furnace damper is leaking would installing another damper above the furnace be the answer?

 

[leon]

Going around the used stove with a lit propane torch or a lit cigar
will help you find an air leak.

Do you have a draft inducer like the "Vacustack" on your chimney??

Are you using kiln dried wood or wood scraps with a finish???

Your fire will run until the fuel (gasses and carbon)supply is exhausted.

You have an air leak somewhere and is sounds like there may be a cracked weld perhaps.
If the door gaskets are shot the dollar bill test will be an automatic fail.

Installing a second damper would be a definite no no.

You need a good manomometer like the Dwyer Mark II with its probe adapter kit
.to correctly determine what your draft reading is. Its entirely possible you have
too much draft and that is a dangerous thing.

 

[ChevyGuy]

Going around the used stove with a lit propane torch or a lit cigar
will help you find an air leak.

Do you have a draft inducer like the "Vacustack" on your chimney??

Are you using kiln dried wood or wood scraps with a finish???

Your fire will run until the fuel (gasses and carbon)supply is exhausted.

You have an air leak somewhere and is sounds like there may be a cracked weld perhaps.
If the door gaskets are shot the dollar bill test will be an automatic fail.

Installing a second damper would be a definite no no.

You need a good manomometer like the Dwyer Mark II with its probe adapter kit
.to correctly determine what your draft reading is. Its entirely possible you have
too much draft and that is a dangerous thing.

Thanks Leon. I do not have a draft inducer system. I do use kiln dried lumber to get the fire started and once in a while throw a peice in here and there, but did not have any in there at the time of this roaring fire issue. I will be doing the dollar test today to check the seals. I have just read several articles about the problems of too much draft with these newer stoves/furnaces. Seems to meet EPA emission standards the factory dampers don't actually allow them to close all the way. I tend to think that I do have this over draft problem. I am ordering that Manometer right now. Q: With double walled pipe can I simply drill the required hole in through the 2 walls and insert the monometer tube? The few that I have looked at online have a bent tube, and that might be a problem to get through the hole on a dbble walled pipe. In other words, can the tube be straight and not curved or bent. I can't see why it needs to be bent.

 

[leon]

Thanks Leon. I do not have a draft inducer system.
I do use kiln dried lumber to get the fire started and once in a while throw a piece in here and there, but did not
have any in there at the time of this roaring fire issue.

I will be doing the dollar test today to check the seals. I have just read several articles about the problems of
too much draft with these newer stoves/furnaces.

Seems to meet EPA emission standards the factory dampers don't actually allow them to close all the way.
I tend to think that I do have this over draft problem. I am ordering that Manometer right now.
Q: With double walled pipe can I simply drill the required hole in through the 2 walls and insert the manometer tube?
The few that I have looked at online have a bent tube, and that might be a problem to get through the hole on a
double walled pipe. In other words, can the tube be straight and not curved or bent. I can't see why it needs to be bent.

==================================================================================================================================================================================================================

You can order these items directly from Dwyer Instruments. Sales Department 219 879-8000h

A straight drilled hole properly sized for the Dwyer 100560 straight manomometer probe outside diameter is all you need.


Go to the Dwyer home page to order this Manomomoter and the probe and you can find them on their catalog pages and find them.
they take plastic money or money orders but plastic money will get everything shipped the same day in most cases as long as you call at the start of business hours.

NOW:

What you need are the following items

1. MARK II 25 manomometer 0-3 w.c. (water column) red fluid
comes with tubing and mounting screws to attach to wall studs or 1 by 6 attached to wall stud


2 100560-00 static pressure tip (kit comes complete)


This is all you need.


FYI you need to soak the tubing in very hot water to get it to slide on the short probe end.

You need to follow the manomometer mounting directions exactly

They take you through them in easy steps and the manomometer must be adjusted correctly before attaching the tubing to the manomometer and then install the probe with the tubing attached to the probe.





You should talk to the stove manufacturer if at all possible too if you can.

 

[STIHLY DAN]

@brenndatomu has them for sale, in the for sale section here. Cheap too.