furnace problems

[Indycheez]

I have an older Hydro Flame furnace in my truck camper that I have a problem with. I did the normal things of cleaning all the nets dead bugs and such out of the system. Got everything cleaned, gas leaks stopped, got the pilot to light(I have the model 8012 that you have to hold and turn the pilot knob) I finally got the pilot to light and the furnace to fire and produce heat. This was on shore power.
I have a Jackery 1000watt power pack with 110 outlets. I plugged into the power pack, blower motor started as it should, pilot lit, but the furnace would not fire. I changed back and forth several time from shore power and power pack. Furnace fired on shore power but not on power pack. The power pack is fully charged and operates normally. What can be the problem? Please help.

[Old-Biscuit]

Roger10378 wrote:
You've answered your own question. 11 Volts does not turn the fan fast enough for the furnace to light.

Winner winner....chicken dinner ^^^^^^^

Airflow moves paddle that closes Sail Switch
Low airflow/slow motor speed....Sail Switch does NOT close therefore DC does NOT go to circuit board for Ignition sequence

[Indycheez]

That's disappointing. Thought since my water pump and my lights worked, the fan would work too.

[Roger10378]

You've answered your own question. 11 Volts does not turn the fan fast enough for the furnace to light.

[Indycheez]

Please forgive my ignorance, I am in no way tech minded. My thoughts is that I could just plug the camper plug into the AC outlet of the jackery and power the whole camper. And it does. The outlets work, The lights work and they are 12V so I assumed it could power the blower since it is 12v too. I did put a multi meter on the thermostat and limit switch both ways, jackery and shore power. The jackery is reading just over 11v, where the shore power is reading 12.5v.

[jkwilson]

Is there a battery connected somewhere or are you relying on a 12V converter? My guess is between the fan and the converter 1000W isn’t enough.

[enblethen]

Verify polarity to the furnace.
Verify voltage to furnace when fan is running.
What output on battery pack? Using jumper cable connection?