Has anyone played with the timer pilot settin on a Gbu130? I am burning straight corn and I have it set on the 8min cycle time.. I did try the 16 min cycle, but as most of you probably know the pilot will not stay lit in between cycles unless there is a call for heat from the thermostat. My unit mainly runs on pilot cycle most of the time anyway, I have my thermostat set @ 70, but the pilot is generally enough to heat my house easily. Is the 16min used for pellet burning?
This is my first experience with corn any help would be appreciated.. Thanks

yes -- 16 is best suited for pellets or a corn pellet mix

it may also be applied if you have a hi daytime draft and a large night time load - but your situation description does not appear to apply to that.

If the idle fire is mostly carrying the load -- the idle fire may be reduced

This can be done in one of two ways:
switch from 8 to 16 - dubious results possible with straight corn
or
reduce the feed cups further
do you have a factory feed cup reducer blocking one of the three cups now?
if no - you can fashion some from 1/4 or 3/8 hard wood and install them with 10/32 machine screws - the hole is already in the bottom center of the cup but you will have to clear it with a pin and a vacuum - a 1/4 inch cup in the bottom of each woks very well, and I have reduced on corn with one shim in two cups and two shims in the third so experiment. As it gets colder and the appliance is staying on hi fire longer - you can pull out a shim at a time to bring more temperature into the heat exchanger - if you reduce too far - its not a drama - save you have to clear the bin to get at the feed cups - a shop vac makes quick work of that.

Keep us in the loop on what you find works!

I have added a quarter inch shim to the secondary feed cup. The third cup was plugged from the factory. I have tried a pellet/corn mixture and may seem to work well for my situation seems to have less smoke than the corn. Probably due to the lack of heat carried in the actual firepot. I also notice that the corn is actually starting to molten into a blob vs burning. If I do a corn/pellet mixture do you think it would be beneficial to remove the shim and up the pilot cycle time to 16min?

I did have an outdoor wood boiler for years and have moved and switched to corn for several reasons. This site has really helped me get a good handle on corn burning I really appreciate everyones help. Will post pics of my setup soon..
Thanks again

If you decide to use a mix -- Yes try the longer idle time setting - worst that can happen is a lost flame. The upper smoke chamber switch will open and the the feed screw will stop.

You can also experiment with your combustion air. As you reduce fuel input, you must also close the combustion air door to keep the air fuel mix in order. There is also a switch to set or turn off the idle air. Use the lowest possible setting yet keep fire. This will depend on your draft potentials.

The object is to keep the unit under HI fire if possible -- reducing the fuel input will reduce the flame and the unit will need hi fire longer. less smoke too

Well I have switched my burn cycle to 16 min and using about a 50/50 mixture. Needed to remove the factory plug that was installed into feeder cup and put a 3/8" plug into that hole. I left the other two cups fully open and adjusted my air mixture accordingly. The unit seemed to do well despite the double time in between pilot cycles. Saves quite a bit of fuel in the process too!

You puled the factory plug and installed a smaller one? In effect Increased the amount delivered under hi fire

but you decreased the amount delivered to idle fire by the timer setting

and

AND

now your using less fuel

Good Job! Thumbs up

With just the two plugs open there didn't seem like there was enough fuel towards the end of the cycle to reignite. By opening up the third cup and reducing it with a 3/8" shim allowed just enough fuel for the last part of the pilot cycle.

Played with the air ratio also, but to my surprise when I reduced the amount to the fan it actually started to make the fan spin faster, causing more pressure, seemed to act like a turbine. when opened back up it allowed the fan to come down to a slower overall speed, but did increase the volume of air. Right now it is set @ about half...

TallCorn ( I think ) made a great example some time ago using a shop vac as an example -- if you hold your hand over the hose preventing pick-up ... What happens

The fan motor speeds up -- not because it is working harder - because the blades it is spinning cannot move air that is not there to move -- ergo: motor load decreases - same thing happens when we choke the flow on the head side of a wet system circulator

So -- you didn't get more pressure - or more volume - you just got was a restriction and the motor reacted to the lighter load by WHAT? Speeding up

if your heat exchanger is nice and white -- cut back the combustion air - lean is good too lean is just heat blown up the stack -- if the soot or smoke is black - your too rich -- ADD AIR

You need a manometer - your ear won't do. Check out the video files of the one JA installed


HEY LOOKIE New record - negative 13

I must be (am) such an asshole