Wood Burning Furnace Gemini Blower kicking On/Off

[Btenkhoff]

New Here to the forum and new to the wood burning furnace world. We bought a house and it has a Gemini 5000 model wood burning furnace. I am not exactly quite sure how it works fully but i have been burning wood and it has been heating the house. I have noticed the electrical usage is still fairly high burning wood. I am guessing it uses the blower on my electric furnace to circulate? Anyways this morning i notice it is turning on for about 4 and a half minutes and shutting off for about a minute and a half. It does this cycle back and forth and has been all morning. Previous to this i noticed it would kick on what i call the blower even when the temperature on thermostat is above what it is set to. I have shut both thermostats off and it still is going . I was told top thermostat runs the wood furnace and bottom the electric side of the AC and furnace. Any ideas as to what would cause this and how this set up works so i can save on electric etc? I was experimenting with electric furnace vs wood and i cannot seem to notice a savings according to my online electric company usage App (assuming that's correct). I tried to load a video but file was too large. Sound from the blower seems to come from the furnace on the left.

Any help and wisdom/knowledge is appreciated.

 

[Btenkhoff]

Just an update at 2:12---its not cycling on and off as frequent but still does more frequent than i believe to be normal even after temperature is met on thermostat control

 

[johneh]

Fan cycling from a wood-fired furnace is normal
All the thermostat does for a wood furnace is control the combustion air
A call for heat opens the control flap/valve so the fire gets more air
When the heat level is achieved the valve closes.
The fire does not go out it just idles and produces heat all the same so when the
The fan limit switch gets warn(hot) enough, the fan turns on to blow warm air from
the furnace to the rooms of your home, this is what is causing the fan cycling
And is normal operation
Your electricity use will come down if you set the electric furnace thermostat at
a much lower temp say 60 so you only heat with the wood unless it gets below 60
or you set the stat higher. You only need to use 1 furnace at a time
I have a wood /propane combination and have used no propane in the last 3 years
Hope this long-winded explanation helps

 

[Btenkhoff]

Thank you for the explanation. That helps me understand the relationship between the wood burning unit and the electric furnace. It kept throwing me for a loop for the fan/blower in the electric furnace to be running. So even though i have the bottom thermostat off(runs the electric) when i am running the wood burning thermostat, i still need to set that bottom one to 60? Thanks in advance for the knowledge.

Also what does that motor on the back of the wood burning furnace do?

 

[johneh]

That looks like a fan that feeds air to the fire in the picture (forced draft)
I do not know your system but as a general rule there is only one fan
in a combination unit and that fan is usually in the first unit in line
So for your system, cool air return (plenum) is on the electric furnace
and the hot air plenum is on the wood furnace. The fan pulls cool air
and forces it out of the hot side
Make sure you change the air filter ofton.

 

[Btenkhoff]

Yeah I just checked the filter today and noticed it was already dirty from 20-30 days. So does turning off the second thermostat that runs the electric ensure that i wont have the electric heater running? Also as a general rule it should be cheaper to run wood/electric fan then just straight up electric heater correct? To me i would think it uses the same amount of electricity but i am no electrician. Thanks again

 

[johneh]

The fan is going to use the same amount of electricity in either electric heat or wood heat.
It is the Electric heating coils that eat up the power.
Don't turn the electric furnace off use it as a backup in case you are away for
long periods but set it low say 60 to keep your pipes from freezing
and the insurance company happy.

 

[Btenkhoff]

Thank you very much! That makes sense. I wanted to make sure I wasn't doing anything wrong and cutting and splitting the wood for the same electric bill either way. I appreciate the knowledge.

 

[Btenkhoff]

Can you run the wood burning furnace if the electric went out? I realize it wouldnt blow as much heat through the duct but would it provide any benefit?

 

[johneh]

I would turn the electric furnace off and heat just with wood
But you do have to be home to keep feeding the wood furnace
I would never run both at the same time unless you needed
a lot of heat fast

 

[Btenkhoff]

I work from home so that helps. I just meant if we lost power to our house can i still build a fire in the wood furnace? It would require electricity to blow but can i use it without electricity. We live out in the country so power outages are more common it seems. - thanks again

 

[sloeffle]

I work from home so that helps. I just meant if we lost power to our house can i still build a fire in the wood furnace? It would require electricity to blow but can i use it without electricity. We live out in the country so power outages are more common it seems. - thanks again

When I had my wood furnace and there was a power outage when I was home I tried to get the fire snuffed out as much as possible. I was going to install an emergency heat dump on my plenum but I sold the wood furnace before doing so. The fan limit switch on my furnace had a setting that when the plenum got up to X temperature ( configurable ) it would turn the high speed tap on the blower to turn cool the firebox down as fast as possible.

 

[johneh]

I know with my unit if the power is out it will draft heat through the ducting (small fire)
But we also have an automatic generator (whole house) because power
outages here are frequent and can last a few minutes to a few days. The big ice storm
of 1998 (Eastern Canada and North Eastern US) The power for us was out for 28 days
That's why I have a generator

 

[Btenkhoff]

When I had my wood furnace and there was a power outage when I was home I tried to get the fire snuffed out as much as possible. I was going to install an emergency heat dump on my plenum but I sold the wood furnace before doing so. The fan limit switch on my furnace had a setting that when the plenum got up to X temperature ( configurable ) it would turn the high speed tap on the blower to turn cool the firebox down as fast as possible.

so based on that its probably not safe to run it as to not overheat the plenum

 

[sloeffle]

so based on that its probably not safe to run it as to not overheat the plenum

You don't want to overheat the firebox. The firebox over heating is probably the bigger issue. As long as the plenum is metal it should be able to withstand the temperatures.

 

[brenndatomu]

-its not cycling on and off as frequent but still does more frequent than i believe to be normal even after temperature is met on thermostat control

Seems like this may be sorted out already, but just to be totally clear, the duct blower kicking on/off has nothing to do with where you have the thermostat set (and if its satisfied or not) the duct blower kicks on when the furnace/plenum hits the set point temp of the fan/limit switch...which is going to happen every so many minutes since the fire is still "on"...with wood or coal heat the fire does not "shut off" like it does with fossil fuels, so there is always a little heat being made, even when the thermostat is satisfied and the combustion blower is off.

 

[johneh]

You are correct

 

[The Dog Pound]

Hoping one of you might be able to help - bought a house with a gemini 5000 wood furnace. No documentation. I am sure it needs a cleaning and some maintenance before I fire it up. Might anyone have a copy of the manual or be able to provide any info on this furnace ?
Many Thanks for any info that can be found