Re: water heater won't work. HELP!!!!!!
Where neither the water heater nor the furnace work, it seems likely that there is some problem that is common to both. The only things that I can think of in common would be the propane or the 12V power. American Appliance was purchased by Suburban back in 1987 and is basically the same water heater as the one sold as Suburban today. You should be able to get Suburban parts that will work on it.
You didn't say what make/model your furnace is, but since neither light, I would first check with the water heater, since it is probably easiest to work with. When you turn on the water heater, check right away to see if the igniter circuit board is getting 12V power at the board. If it isn't then we trace back from there to see where it is getting lost. But I suspect that it is getting power. If so, check to see if you can hear the igniter snapping as it sparks. If you check after dark you can see the sparking. It should try about three or four times.
I would also check for power to the gas valve, and use a lighter to see if there is any propane going through at all. It could be a problem with too little propane pressure. You can ball park test that by turning on the stove top and watch the flames. They should burn blue, with slight yellow tips to some of the flames. Once you have one burner lighted, start the second and then third and each one should have no effect on the already burning ones. If the color is not right, or if the second one effects the flame of the first, you probably have low propane pressure.
I assume that you know that you have a good supply of propane?