My model number for my thermostat is 42204 auto save programable and I am experienceing problems setting the tempature,i changed the battery,yet it is still not setting the right temature.It will light the furnance yet it will only run for a minute or minute and a half,then shut off. I beleive that it is broken,and needs to be replaced,or if i could get the manuel so that i might set the programs correctly. PLEASE HELP, It is getting cold here.