You mention a rocker switch on a panel, is there also a Heat/Cool rocker switch on the same panel? Sounds like the blower relay is bad.

It is screwed into a small pipe coming out of the control valve inside the body of the furnace. Basically it's where the gas comes out to be burned to produce heat in the heat exchanger. Actually very few problems associated with the oriface. Only one I know is a spider web, provided the furnace is ...

Repairing the old stuff is a waste of time. The lumber is way dried out and really was a crap system when it was originally installed. Did many of these when I was younger. We always cut and installed new rafters out of either 2x6 or 2x8s depending on the height of the original truss style rafters. ...

If you have a dishwasher, washing machine or ice maker be sure to empty those as well. Also run some antifreeze through the dishwasher and washing machine drain cycles. A gallon each will protect them.

Metal roof or shingled roof?

Unless you have the crimp tool for the rings on the PB and Pex tubing this job is better left to a plumber that does. Standard SS hose clamps will not apply enough pressure to properly seal the fittings and I wouldn't trust the slip fit fittings that are available unless it is a "no choice"...

Hoppy if the control valve isn't opening fully there will be a tall yellow flame when on LP gas. Should look sort of lazy as well. That is a slow opening/staging valve on that furnace, actually I haven't ever seen a mobile home furnace that wasn't like that. You can try whacking/tapping the side of ...

My suggestion is as above: check main burner oriface for spider web.

If everything is "clicking" correctly and igniter is not glowing, replace igniter. I would test for power to the igniter first with a multitester. You should get 120v to the igniter terminals/plug at some point during the start up process. If you have power then igniter is bad.

Very strange for valve to fail in "on" position. Checking pressures in and out will let you know what valve is doing. If water column pressure going in is good and out is wrong then valve is bad. Correct pressures are listed on furnace data plate. 20 years....might also check the heat exch...

My fault...they are still available. Just don't see any "newer" ones in my area. Use a mirror and flashlight to see if the duct work is clear. Are the fins on the floor registers bent closed? Pull them all out for a day or 2 to see if that helps. Any chance there is a solid door as access ...

That's high but there's another problem you're not catching, not moving enough air through the furnace, hole in the heat exchanger, blockage in vents, etc. Did you ever replace the blower motor? Was it the right one? Has the heat exchanger been inspected? That's an OLD unit. Is the asbestos pot (com...

Sounds like the control valve is working properly. Can you check water column pressure into and out of the control valve? Easier yet, was the furnace set up properly to run LP gas? Natural gas operates at lower pressures and will have larger orifaces. Are the proper orifaces in place in the pilot an...

2 blinks is a flash code. Should be a data sheet attached someplace on the furnace near the control box that states the flash code status. Could also be on the backside of the electronics cover panel for the furnace. Locate that and it will help you diagnose your problem.

Yes igniter is flame sensor. If burner ignites then goes out shortly afterwards either the igniter is positioned incorrectly or there may be a spider web in the main burner oriface that is blocking the flow of gas to support the flame.