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jheitman
01-03-2011, 06:00 PM
I noticed that each time the furnace started it only ran for a few minutes and shut off and then restarted again in a few minutes. It would go through maybe 4 cycles before the thermostat was satisfied and would then stay off for maybe 30 minutes or longer, depending how cold it was outside, before starting another set of cycles. I worried that something might be wrong with the furnance and some overheating limit switch was cutting it off. We only have 5 floor vents total in our 32RE, none directly in the bedroom. Although the 35 kBTU furnance keeps the unit nice and warm, in my opinion it was short cycling.
I started looking at the vents and saw that each had a series of vanes, half pointing one way and the other half pointing the opposite. See photo.



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We have one vent on the upper stairway landing, in the hallway, right about under the thermostat. I noticed that the rearward set of vanes seemed to point directly at the thermostat. See photo.

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This shot was taken from the ceiling looking down in a line straight into the rear floor vent vanes. You can see the thermostat is right in line with the air blast from those vanes.

So I tried a simple experiment that seems to work perfectly. I placed a block, a note pad or shoe, over the half of the vent that blows directly at the thermostat, this is the set of vanes shooting down the stairway into the doorway area. This probably pushed a little more air up into the bedroom which was just fine. See photo.

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This shot is also taken from the ceiling looking down on the stairway, see my feet.

This simple modification has made a big difference. When the furnance comes on it stays on and only cycles once for each heating period. The bedroom seems a little warmer too. When the furnance starts it needs to warm up and then the fan runs after the burner stops to cool down the heat exchanger. When the furnance is short cycling it is on a lot and it does make a bit of a loud noise.

Give it a try and see if your Greystone furnance runs more smoothly, and also runs less time, making less noise. You can place anything over the aft set of loovers, I have used a shoe most of the times...

I believe that the warm air blowing by the thermostat was heating it before the room was heated causing the thermostat to cut off the furnance early. Once the air was off the thermostate cools rapidly and restarts the furnance.

It would be interesting to see what the factory has to say about this.

jim :o

2psnapod2
01-03-2011, 08:10 PM
It certainly does look like the vent is blowing on the thermostat. I would think that Home Depot or Lowes or some other store like that would have a new vent that would have a flapper that could be shut off completely or divert it away from the stat.

jheitman
01-03-2011, 10:29 PM
It certainly does look like the vent is blowing on the thermostat. I would think that Home Depot or Lowes or some other store like that would have a new vent that would have a flapper that could be shut off completely or divert it away from the stat.


Have you seen anyone selling a 4x12" floor register that has vanes only pointing in one directing?

2psnapod2
01-04-2011, 06:36 AM
You could always go to a heating company. They have a large selection that they can order.

currituck0209
01-04-2011, 08:13 AM
I have a Sundance XLT, which has the vent directly under the thermostat, I purchased a new one a Lowe's that will redirect the air or close. It fixed the problem.

jmgratz
01-04-2011, 03:43 PM
Hey Heartland...poor design...needs to be changed....

TravelTiger
01-04-2011, 06:47 PM
http://www.dyersonline.com/rv-designer-tan-2-3-8-x-10-floor-register.html

We installed these. They have an adjustable damper that can angle the outflow or cut it off. (louvers still point the same directions as the old.)