Hydro Flame 8552 furnace shows parasitc battery drain

les1cam wrote:
So; should I change out the thermastat?

NO. The tstat is just an ON /OFF switch. You pulled the furnace fuse, but the odds are there are OTHER appliances on that circuit. Very few RV's run just the furnace on the 1 fuse. Your .5 amp draw will NOT drain a battery (GOOD fully charged battery) in a week much less a few days. Doug

So; should I change out the thermastat?

I arrived at my Furnace draw when something wound drain my battery after a few days of total non-use. I hooked up my multimeter crossing from my negative side of the battery to the neg. cable. Amp reading when set on 10 amp guage indicated .553 amps. I pulled fuses until the reading went to .05. That was the 15amp furnace fuse.

12V DC power is at circuit board but should be no draw (current) until t-stat contacts close making a path for current to flow.

Could be dirty/tracking on circuit board.

How did you confirm your furnace draw and what made you trace a draw and to the furnace? Did you disconnect the 12 volt power to the furnace and your draw went away? What type tool did you use to measure that .5 amp draw? I do NOT believe a correctly operating furnace has any parasitic draw when not being run. The circuit boards do not draw any current when the system is OFF on a correctly operating furnace. SAME with a DSI Water Heater. The use the same basic module board. Doug

That may be right, about 500 MA (1/2 amp). The circuit board is always powered.