How do you set an adjustable thermostat?

[Larry B]

It is very,,very cold here today, my truck read -33 (-22F) this morning on way to shop. Hope it is warmer where you live. I recently had my propane furnace out to check it over as it would sometimes not always start. I did a general check and found the spark gap very wide as per book. Reset gap and after bench test of furnace put back in bus. all seems well so far but question is for those that understand how this heat antisipator ( I think that is what it is called- basically a small heater) inside the thermostat works. When the 12 volt power is connected to furnace, that also send power to one of thermostate leads. Right now it is as if the thermostate is too sensitive and it cycles off/on a lot. In the picture one thermo lead is connected to yellow wire (back side) and one to screw lower right. Does it matter which one I make the incoming 12 volt lead? Also in the picture where the paper clip is pointed at -- that small brass arm will swing thur an arch and follow that fine wire and makes a small amount of heat and causes the thermostate to override the setting , thus causing less cycling.  I do  NOT understand this thing fully, just what I am reading on web. Need some help in knowing where to set arm. The cycling does not bother me, but I know it will annoy wife. Hope that small wire shows up in picture, I have fatter grey hairs on my head than that wire thickness. Thanks
          Larry B   

[Nick Badame Refrig/ACC]

Hi Larry,

Sorry, I was thing you had a bimetal set-up....

A better way to resolve your issue would be to purchase a digital programmable home type t-stat because

you can change the differential  up to 3 degrees.

No, it doesn't matter which wire goes where with a two wire set-up.

Good Luck
Nick-

[eagle19952]

you could just set it for 80 degrees.. if it never shuts off, then you will know that the short cycle is because your coach cannot overcome the outside ambient.... -22 is pretty cold for coach living.

[bevans6]

http://inspectapedia.com/heat/Heat_Anticipator_Adust.htm seems to cover the heat anticipator pretty well.

Brian

[oldmansax]

Before Digital t-stats, I used a mili-amp meter to set the anticipator as outlined in the article Brian referenced.

TOM

[baker4106]

That is an anticipator and will determine how quick furnace cycles.   You need to get a amp reading on the t-stat wire.   Set the anticipator accordingly.   Might try moving lever a little one way or the other and see how the furnace operates.

[Larry B]

  Thanks for all the replies The site Brian point out clears up a lot of confusion I was having. Will try getting an amp reading and set arm accordingly. Way TOO cold to be living my bus. I am trying to get all the little issues taken care of before wife and I make a trip to Maritime provinces hopefully next summer. Thanks again
         Larry B