I put in a new transformer, and just put in a new board. A couple of days ago I went to shut my heater off and there was no led on the controller. There is still no 24vac getting to r & c where the wires from the thermostat connect. and when I close the door the fan comes on, the only way I can shut it off is to unplug it or leave the door off. I'm just perplexed as to why there is no 24v to the stat. On the board I am getting 24vac to the gas...so....

KC13

Start by posting brand/model # of the heater. If blower runs continuously and you are lacking control voltage, this is usually caused by an open limit switch of some type.

ameriman1

it's a carrier model 394jaw036065 I am pretty sure it's a limiting switch and am suspecting it's the vsss (vent safety shutof switch) but I don't know where it's at. I was looking at the schematic and it says it's a manual reset

KC13

If both schematic and ladder diagrams are present, colors of wires connected to these devices would be indicated. There's your clue. Vent/draft safeguard switches are usually located closer to the flue, inducer, or draft diverter.

ameriman1

man I looked everywhere...unfortunately the schematic shows the breadboard exterior and interior. I followed the line and there is nothing on it...according the the schematic, the vsss is inline on 'R' and looks like has a hook into sec 1....I went out one line and was looking at vsss switches....there is nothing like that on this thing that I can tell.

ameriman1

ya, that was it....I found it....geez...should have read more carefully could have saved myself 140.00....well, at least I have new electronics...should last for another 20 years haha...

thanks man, that was the trigger I need to get my brain working...

KC13

Pass it on...