yet another hf-70 keystone question

My hf -70 is cooking along very nicely and I'm getting at least 12 more like 15 hours between fillings.
I think it could go longer but I don't want it to go out
If anybody has used one of these stove on the back there is a air intake that has a dial and a bimetal spring deal that is supposed to act like a crude thermostat I think.
It allows air in thru a 2 inch square hole that has a flap over it ,I have this closed right off and blocked off so little or know air gets thru.
On the ash door in the front there are slots that allow air under the fire these are also closed.
I took a lighter and held it over the door vents and it sucked the flame right in so even with them closed air is still getting in.

My fire stays about 350 -400 very constant my question is this could I block off the vents with something to slow the air infiltration down even more the house is staying very warm .
It has all new gaskets and seems to be burning great I just think it would burn allot longer if I stopped the air.
I have this fear that it will suck so hard it will break the glass do you think that would happen.
The manometer is set and stays at .03 ish all the time and the baro is open all the time.

My wife thinks I need to go to coal stove rehab

Thanks for your help again

Tim

Hi Tim, is the plate that slides over the vent slots in the ash door loose?? It should fit tight up against the door surface to block the air. Usually there is either a bolt with a nut or maybe a nut and a compression spring to adjust the plate clearance. Adjust it tight so you don't get the air leakage past it when closed. You should be able to cool your fire down further than it is burning now.

Greg L

The front ash door and sliding air intake are fairly tight but they are cast iron so it is rough and leaks some.
A magnet sticks to the ash door and can block the air nicely. I don't want it to suck to hard could it break the glass with a lot of draft??
Is 350 -400 to warm is that what you mean buy YOU SHOULD BE ABLE TO COOL YOUR FIRE DOWN MORE

mina678 wrote:The front ash door and sliding air intake are fairly tight but they are cast iron so it is rough and leaks some.
A magnet sticks to the ash door and can block the air nicely. I don't want it to suck to hard could it break the glass with a lot of draft??
Is 350 -400 to warm is that what you mean buy YOU SHOULD BE ABLE TO COOL YOUR FIRE DOWN MORE

Have you replaced the Gaskets on both doors If it is getting Air in with all of the air vents blocked then either The door's gaskets are no good or The doors or warped or you might have a crack in the stove some where First replace the door's gaskets That might be your problem if it works Then I would use the second dairy air source that is what you are blocking
off in the back it is a Bi Metal Thermostat You would set that so when the fire starts to die down it would open to let more air in to help keep the fire going with that set right you should get much longer burn time with a full load of coal

The caskets are all new and I don't think there is are any cracks since it has been burning for a couple weeks and know co2 problems.
So are you saying the 350 -400 temps are to high they are just taken off the top of the stove with a magnetic thremometer so it is just a guidline I will get a more accurate temperature reading We have a laser thermometer at work.Also this stove has an air space around it sort of double walled and a small fan blowing the air off the stove.

I just want to be able to slow the burn a little more a minimize my coal usage which is not very high in my opinion, especially on the warmer days.
I only fill twice a day and only add 1 or maybe 11/4 coal skuttles per day and by the lenght of my burn i thought it was doing good

mina678 wrote:My wife thinks I need to go to coal stove rehab

Forget it, there is no cure, it is a lifetime affliction.

You may have to remove the sliding vent plate, and sand/file/grind the surface smooth so the air will not be able to get past the rough surfaces. You should be able to reduce the airflow to the point the fire all but goes out.

You don't have to worry about having so much draft to crack the glass, if you had that much draft, you couldn't open the door against the suction. .

Greg L

if you had that much draft, you couldn't open the door against the suction. .

Good point thanks

Tim