Furnace not coming on

[Quail]

I have the same problem when on battery power. I move the thermostat and I can hear that faint click inside the thermostat but the fan does not come on, so nothing happens. If I plug the trailer in, I hear the faint click in the thermostat, the fan comes on, then the click click click of the igniter, the rumble of the gas igniting and then heat. Unplug the trailer no heat.

[rockfordroo]

Originally Posted by Quail

I have the same problem when on battery power. I move the thermostat and I can hear that faint click inside the thermostat but the fan does not come on, so nothing happens. If I plug the trailer in, I hear the faint click in the thermostat, the fan comes on, then the click click click of the igniter, the rumble of the gas igniting and then heat. Unplug the trailer no heat.

Sounds like your battery isn't fully charging. Bad battery or bad converter, or both.

[Quail]

Battery test ok and fully charged. Frig works fine on 12 volts.

[CHICKDOE]

so we know the problem is not with the furnace itself. you say it runs fine when connected to shore power. the furnace is a 12 volt device. when connected to shore power the converter is supplying the required 12 volts. yet it does not run on battery power. the furnace blower is a large consumer of 12 volt power that must be supplied by the batteries when not connected to shore power. you say batteries test ok and refer works fine on batteries. by using these statement you are implying that the batteries are not the cause of the heater not running. the refrigerator uses only a very small amount of 12 volt power when on batteries. only enough to power the control board. this is nowhere neat the same level of power that the heater fan requires to run. you say batteries test ok. what does this mean? what test was done? have you pulled them and had them load tested? i am very suspicious of the battery capacity being unable to supply the power needed to run the heater fan when not connected to shore power. a voltage measure measurement by itself may not be a true indication on battery status.

[rockfordroo]

Originally Posted by CHICKDOE

so we know the problem is not with the furnace itself. you say it runs fine when connected to shore power. the furnace is a 12 volt device. when connected to shore power the converter is supplying the required 12 volts. yet it does not run on battery power. the furnace blower is a large consumer of 12 volt power that must be supplied by the batteries when not connected to shore power. you say batteries test ok and refer works fine on batteries. by using these statement you are implying that the batteries are not the cause of the heater not running. the refrigerator uses only a very small amount of 12 volt power when on batteries. only enough to power the control board. this is nowhere neat the same level of power that the heater fan requires to run. you say batteries test ok. what does this mean? what test was done? have you pulled them and had them load tested? i am very suspicious of the battery capacity being unable to supply the power needed to run the heater fan when not connected to shore power. a voltage measure measurement by itself may not be a true indication on battery status.

X2

[Mr. Dan]

Originally Posted by CHICKDOE

so we know the problem is not with the furnace itself. you say it runs fine when connected to shore power. the furnace is a 12 volt device. when connected to shore power the converter is supplying the required 12 volts. yet it does not run on battery power. the furnace blower is a large consumer of 12 volt power that must be supplied by the batteries when not connected to shore power. you say batteries test ok and refer works fine on batteries. by using these statement you are implying that the batteries are not the cause of the heater not running. the refrigerator uses only a very small amount of 12 volt power when on batteries. only enough to power the control board. this is nowhere neat the same level of power that the heater fan requires to run. you say batteries test ok. what does this mean? what test was done? have you pulled them and had them load tested? i am very suspicious of the battery capacity being unable to supply the power needed to run the heater fan when not connected to shore power. a voltage measure measurement by itself may not be a true indication on battery status.

x3

[Quail]

Please rest assured I load tested the batteries in my shop before I carried it out there. 40 years of turning wrenches, marine and auto had taught me not to waste my time. More info. No voltage drop at the battery when thermostat is turned on.

[rockfordroo]

Originally Posted by Quail

Please rest assured I load tested the batteries in my shop before I carried it out there. 40 years of turning wrenches, marine and auto had taught me not to waste my time. More info. No voltage drop at the battery when thermostat is turned on.

Well, when you figure it out, be sure to come back and let us know what it was. Maybe we'll learn something new.

[Quail]

When the snow melts and I get the cover off I'll figure out what it is I'll let you all know.

[cavie]

Originally Posted by Quail

Please rest assured I load tested the batteries in my shop before I carried it out there. 40 years of turning wrenches, marine and auto had taught me not to waste my time. More info. No voltage drop at the battery when thermostat is turned on.

Did you do an Electronic load test or a resistance load test. Old school vs new school?

[Quail]

Resistance, I only do what works everytime.

[Quail]

And now for the rest of the story I check the furnace for 12 volts. I found I had 12 volts at the furnace but my fan would not run. I checked the thermostat the thermostat tested good. One I found was my camper has a battery disconnect the disconnect have failed to make good contact they gave me 12 volts but no working amperage. All of my lights worked and did not dim when I turned on the furnace because I have converted them to LEDs. Because they are LEDs they use almost no amperage and are self-regulating. When I tested the battery I had removed it from the camper, so of course the battery test to just fine and it was. So after finding the source of the problem I tried again to start my furnace the fan ran but it would not liked. Who would guess that my three-year-old LP gas regulator would fail in the last two weeks.

[Obazswm]

My ‘18 Roo 233s is having the same issues, furnace no starting up but I also noticed the compressor for the ac was not kicking on. The ac fan would run in manual on hi and low. I tested the thermostat and that’s the problem. So I will purchase the honewell t-stat but noticed there is no hi/low for the fan? Rockfordroo does this affect your AC in anyway? Any photos on the wiring for the Honeywell t stat?

[Obazswm]

I just looked back through this thread and saw the conversion wiring diagram from a Coleman Mach to a RHT111. Thank you all this forum rocks!! Also sorry for the hijack.

[5picker]

Originally Posted by Obazswm

My ‘18 Roo 233s is having the same issues, furnace no starting up but I also noticed the compressor for the ac was not kicking on. The ac fan would run in manual on hi and low. I tested the thermostat and that’s the problem. So I will purchase the honewell t-stat but noticed there is no hi/low for the fan? Rockfordroo does this affect your AC in anyway? Any photos on the wiring for the Honeywell t stat?

The A/C compressor WILL NOT RUN in FURNACE mode but the fan WILL on certain models with a digital thermostat. It is designed to work that way when the fan mode is set to hi/lo. It helps distribute the warm air from the furnace as warm air rises. If it is set to AU/AUTO, the A/C fan won't run when the furnace is on.

I don't believe you have a thermostat issue as far as the fan goes.

[Obazswm]

I would slide the switch to ac and the compressor would not kick on, the fan does unless it’s in auto. I jumped the red and yellow wires and then the compressor kicked on. Same for when in heat mode, I jumped the red and white leads then furnace fan kicked on and then 15 seconds or so later the furnace ignited. This leads me to believe it’s a T-stat issue. HTH

[rockfordroo]

Originally Posted by Obazswm

My ‘18 Roo 233s is having the same issues, furnace no starting up but I also noticed the compressor for the ac was not kicking on. The ac fan would run in manual on hi and low. I tested the thermostat and that’s the problem. So I will purchase the honewell t-stat but noticed there is no hi/low for the fan? Rockfordroo does this affect your AC in anyway? Any photos on the wiring for the Honeywell t stat?

I got a micro switch from Radio Shack (they're gone now ) and installed it in the side of the T-stat. You have to do some carving of the plastic to allow it to fit. Pics below. However, if I had it to do over again, I would get a real RV style rocker switch (PN on the PDF in Post #18) and install it on the wall next to the T-stat. You might want to take a good listen to the speed difference between hi and lo. It's not very much and maybe you can live with just one. Or live with one until you're ready to do the switch mod.

I didn't take any pics of the wiring, just the switch install.