Hotblast Year 3

Then if no coal exhaust smell detected by anyone, there is one other possibility,......... a false alarm, or false positive reading as some might call it.

I just did a search for "carbon monoxide detector false alarms" and found this talk forum thread of Fireman discussing frequency of their Departments getting CO false alarm calls. Seems they can happen quite a bit.

https://forums.firehouse.com/forum/firefighting/firefighters-forum/29590-false-alarms-with-carbon-monoxide-detectors

There is also mention that newer models with certain features seem less prone. Might be a good reason to check if your brand/model is more prone and get one rated least prone.

I know when smoke detectors first came out we had occasional false alarms. Turns out it was caused by small spiders building nests inside the detectors. Haven't had that problem with the newer ones.

Paul

I have the units with the 10 year batteries, wrote the purchase date on the back. No worries about batteries going dead or having to locate them at an electrical receptacle.

Thanks for the info, Paul.
These 2 unit are new, battery operated Kidde's.

I never had any when I started burning several years ago.

It doesn't seem to be a false positive to me.
I had a second unopened unit that I opened and sat beside the other one.

They both rose to 30ish and then dropped back to -0-.
I'd think a false positive would only affect one unit.

When I cleaned my pipes, yesterday, there was some junk in there but not enough to completely clog it.
Although I've learned that the Shop Vac method of blowing out the chimney isn't thorough, I didn't get much out of the top when blowing or much at the bottom cleanout.

I'm starting to believe it had something to do with the tending.
I had the firebox really full and the fire wasn't that hot.

I don't know if enough CO could leak out through the secondary opening and/or the primary

I don't recall, do you have a manometer connected?

I remember having a lot of issues with "Puff Backs" on my old Hot Blast. Actually I called it "Locomotive"! Maybe this was happening when you weren't there? After switching to the the Firechief, no more puff backs...Same stove pipe and double insulated pipe/chimney....

I don't recall, do you have a manometer connected?

I do but don't trust it.

I will occasionally get puffback and have to close the secondary air for a little bit.
I usually get them when adding.

This event was over 2 hours after that

larryfoster wrote:

I don't recall, do you have a manometer connected?

I do but don't trust it.

I will occasionally get puffback and have to close the secondary air for a little bit.
I usually get them when adding.

This event was over 2 hours after that

When getting puff backs, and while adding coal, u need to give it full secondary air or have the load door even propped open, if you shut it all off your risking a big explosion.

Even have to do that with Anthracite. I would think it's very important with bit.

When getting puff backs, and while adding coal, u need to give it full secondary air or have the load door even propped open, if you shut it all off your risking a big explosion.

Maybe we're describing 2 different scenarios.
With mine, if I don't reduce secondary air, smoke pours out the load door vents

larryfoster wrote:Thanks for the info, Paul.
These 2 unit are new, battery operated Kidde's.

I never had any when I started burning several years ago.

It doesn't seem to be a false positive to me.
I had a second unopened unit that I opened and sat beside the other one.

Don't assume the second one is any better than the first. There is nothing to rule out that the same model won't have the same fault if a false readings is because of design, and/or, of something done during production. Mass production sometimes makes a mass of faulty products. That's why there are recalls of products all the time.

They both rose to 30ish and then dropped back to -0-.
I'd think a false positive would only affect one unit.

What made them go to 30 and then drop back to zero ? Did they drop to zero without moving them, or did you take them outside and then they dropped to zero ? We need more detailed info to try to help.

When I cleaned my pipes, yesterday, there was some junk in there but not enough to completely clog it.
Although I've learned that the Shop Vac method of blowing out the chimney isn't thorough, I didn't get much out of the top when blowing or much at the bottom cleanout.

I'm starting to believe it had something to do with the tending.
I had the firebox really full and the fire wasn't that hot.

I don't know if enough CO could leak out through the secondary opening and/or the primary

CO might, but so will all the other gases that your stove produces. You said no one smelled coal exhaust in the house when the detector went off. Yes, CO is a colorless, odorless gas, but there are many other gases that make up coal exhaust and they STINK !!!! So how could the CO be present without all the other burning coal stink ? Does anyone smoke - even a visitor ? Is there any chance someone had a candle, or anything else lit ? Does the kitchen stove use pro-pain ?

Paul

The kitchen stove uses propane.
When the other units rose later to 30 and went back down, they did so on their own with no movement.

I smoke but wasn't home.
No candles, although my wife does burn them.
She doesn't think she was cooking and baking.
The fact that no one smelled anything means nothing.
Not being rude but my wife and daughter have little situational awareness.

What is your propane furnace connected to for venting? Did the propane furnace run on that morning the CO alarms sounded? Can you rule out the possibility that the propane furnace could have caused the CO problem?

Where was the CO alarm located when it sounded?

I'm not buying that exhaust leaked from the furnace and nobody smelled burning tires in the house. Whenever I had even a mild puffback with bit coal the whole house would reek of burning tires.

I'm just looking out for ya partner. CO caused by propane is completely undetectable (other than by a detector) because there is no associated odor with it, unlike coal exhaust.

Since I wasn't here when this happened:

What is your propane furnace connected to for venting?

I have a double flue chimney.
The propane furnace is a stainless liner in a separate flue.

Did the propane furnace run on that morning the CO alarms sounded?

It may, possible, have run sometime over night while I was asleep but not within 6 hours or more of this event.

Can you rule out the possibility that the propane furnace could have caused the CO problem?

With near certainty.
The coal furnace has been keeping the dining room in the mid to high 70s once I get it cooking for the day.
The propane furnace at 65.
This is the same room that has the propane thermostat and the CO detector.
The detector is sitting in the middle of my dining room table.

I'm not buying that exhaust leaked from the furnace and nobody smelled burning tires in the house. Whenever I had even a mild puffback with bit coal the whole house would reek of burning tires

As I said, neither my wife nor daughter have situational awareness.
It may have smelled of burning tires and they may not have paid any attention and they can't remember anything about what they were doing or what was going on other than the alarm went off.

I'm tickled if it's not the coal furnace.
I do think Paul's theory of two separate detectors reacting the same way and giving the same "false" reading sitting within a couple feet of each other may be a bit of a stretch.
But, it's as good as any other idea right now because neither detector has moved from -0- since relighting last evening.

And if finches are the same as canaries in a coal mine, I have 3 sitting within several feet of the detector that sounded.
They showed no effect

Okay man, sounds like you are pretty convinced it was the coal furnace. The only thing I can suggest is that the fire ran down so low that it wasn't producing enough heat to keep the draft moving the right direction. That's why I was so curious of the condition of the fire when you arrived at home that day.