Enviro Milan heat sensor keeps going off, any suggestions??

[BARTSFAM]

Hello;
Last night I noticed the stove burning really hot. The bricks on the hearth were extremely hot. The stove shut itself down. Light #2 was blinking, indicating the heat sensor had tripped. I cleaned the stove and noticed the burnpot was full of a "pumice" like material, that easily came out with a screwdriver. I just switched two days ago to Lignetics, so I assumed I got a bad bag, as they were very dark, and did not seem to burn properly. I assumed the full pot somehow caused the excess heat, causing the heat sensor to trip.

I cleaned the stove, reset the heat sensor, and put in New England pellets. It burned fine for 8 hours. This morning, the stove burned really hot again, and again it shut itself down, light #2 blinking indicating the heat sensor was tripped. The burn pot this time was fine, no build up.

I last cleaned the stove, stem to stern, 3 weeks ago. All blowers and fans seems to be working fine. I am burning on setting #4, which is not even the highest setting. Is there some sensor that is failing and causing this?

Any suggestions?

 

[SmokeyTheBear]

Check your convection fan for dirt on its blades, clean if dirty, and dirty means even a fine layer. If that fan can be oiled using the recommended oil, oil it.

Determine how long you are supposed to be able to fire the stove at the #4 firing rate.

 

[BARTSFAM]

SmokeyTheBear; are you still there?

Bear with me, I am really not mechanically inclined.

I have kept the stove on Level 4 for 3 years, 24/7, and the heat sensor has never tripped.

There's two fans. I imagine you do not mean the exhaust fan connected to the pipe going up the chimney? You mean the main blower fan, right?
Is it easy to take apart?

I recently cleaned the exhaust fan. I took it apart, and cleaned it real well. Could I have screwed something up when I put it back together?
I did not clean the other blower because it looked too complex, and it was not easy to get to.

Thanks, Jim.

 

[SmokeyTheBear]

I mean the convection fan (room blower, room fan), that is the one that moves air through the heat exchanger.

When they get dirty they don't move enough air to cool the heat exchanger. If the heat exchanger doesn't get enough cooling air it will gradually heat up, once it reaches the magic, ouch it is too hot, temperature the stove shuts down and signals it is over temperature.

Couple a slight airflow impairment with a change in pellet quality (which happens even within the same brand) that increases the density of the pellets what used to work no longer does.

ETA: I have no idea how hard it is to get your room blower out to clean. You shouldn't have caused any problems by cleaning the combustion blower. It may however have resulted in a better air flow through the stove leading to a hotter burn.

 

[BARTSFAM]

Hello;

So I took the convection fan out. It was filthy with dust bunnies. I cleaned it, and it looks great. I put it back together, and fired up the stove. I looked in with my flashlight and realized that the fan is not even spinning.

I pulled it all out, and connected the fan directly to an outlet with an old extension cord. The fan worked perfectly. So....the fan works outside of the stove, when I rigged it with an extension cord, but will not work in the stove when hooked up properly.

I called the dealer, and he said it sounds like the motherboard is gone.

Anyone else have any other suggestions???

 

[SmokeyTheBear]

Hello;

So I took the convection fan out. It was filthy with dust bunnies. I cleaned it, and it looks great. I put it back together, and fired up the stove. I looked in with my flashlight and realized that the fan is not even spinning.

I pulled it all out, and connected the fan directly to an outlet with an old extension cord. The fan worked perfectly. So....the fan works outside of the stove, when I rigged it with an extension cord, but will not work in the stove when hooked up properly.

I called the dealer, and he said it sounds like the motherboard is gone.

Anyone else have any other suggestions???

Did you allow the stove to come up to temperature?

Those fans don't come on the instant the start button gets pushed.

If the stove was out of startup and the fan wasn't running then a loose connection or bad controller.

 

[BARTSFAM]

Thanks again Smokey!!

I was not patient enough. When it came up to temperature, the fan kicked on.

One more thing..when you said to maybe oil the fan. I didn't. I cleaned the heck out of it, but was not too sure about where or what to oil. I didn't see anything about oiling in my maintnenance book, so I didn't.

I have read on other posts, sometimes there are holes for the oil?

Thanks again, Jim

 

[SmokeyTheBear]

Anytime.

Usually what gets oiled is the motor bearings, but that depends on the type of bearing which also sometimes depends on the type of motor the open frame units like on a lot of augers sometimes take grease and not oil.

Sometimes the bearing that the shaft ends rest in (depends upon the fan assembly) also needs lubrication. I'm just working from a cover all the common grounds semi usable script. So sometimes I mention something that might not apply in a particular instance but by doing things that way a lot of folks finally read their manuals ;-) .