Blower on colman gas furnace will not come on. (have no gas yet)
I'm not a furnace technician. But I have worked on several Coleman trailer furnaces. So keep in mind that my terminology might not be exactly correct. But I think I can help you.
I don't know what model you are running, but most of them run pretty much the same. You have a four basic components to check. Thermostat; Ignition Control Module; Pressure Switch; and which ever of the following that you have (Glow plug, Electronic ignition, Pilot Light).
I'm assuming that you are referring to the blower as the "Rat wheel blower" (round wheel looking thing with fins on it). If my assumption is correct and if the power from the breaker box to the furnace junction box (Probably with a on and off switch on top or side), than when you give it power (from breaker box and turn thermostat up) the fan (not blower) comes on. If it doesn't there is a probably a problem with your Thermostat or Ignition Module. If it does come on and your glow plug or you igniter tries to work. Than yes, you are correct, you have to have gas pressure to let the pressure switch know that there is adequate gas supply pressure (gas- 5 to 7 W.C, propane 11 to 13 W.C). The reason for this is if the Pressure Switch doesn't feel the correct pressure. It thinks you have a leak and won't release gas for ignition. After you turn the gas on. If the furnace doesn't ignite. Make sure the Thermostat is definitely wired properly. Now we are down to one of three problems. If the Glow Plug, Electronic Ignition, or pilot light are working properly. Than we are down one of two problems. The Ignition Module or Pressure Switch. Check pressure on the Pressure Switch. If yuou don't smell gas it is probably OK. But it is best if you use a manometer. I have rarely found Pressure Switches bad. Normally if I get to that step. It is the Ignition Module. The Ignition Module kind of like the brain of the furnace. It is located behind one of your front panels. It will have approximately 10 wires going to it. Some will be going to the Thermostat, some to the Glow plug (Igniter), some to the Pressure Switch, and some going to the blower.
I have probably said more than you need to know. If I did I apologize. But to wrap it up. You were probably correct. You definitely need gas for the blower to kick on. The furnace has to light and heat up before the blower will Start. Not to keep rattling, but to check to see if the blower motor will run. Is to switch the Thermostat from "auto" to "run".
Nov 17, 2008 |
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