Atwood 8525 IV Furnace - No Blower Run

bobndot wrote:
just a thought , Does your older style thermostat have this anticipator?

If the fan will not start you should first check that your battery is good and you have 12 volts at the furnace. You could have a tripped circuit breaker or blown fuse.

If the battery is good and you have electricity to the RV's heater next check the thermostat.

Remove cover and look for the "anticipator" adjustment. (Note: Some new thermostats do not have an anticipator.) It will be an adjustable control with a sliding contact over a straight bare wire or a bare wire wound about an insulating material. If the fan will not start set the temperature to maximum and then move the anticipator slider while listening for the fan to start. Be sure to wait long enough... it normally takes our furnace 30 seconds for the fan to start once the thermostat sends a signal.

If the fan starts after you move the slider then you have probably found the problem. In this case you may find a slider position near the original position that will work reliably. If your thermostat anticipator adjustment uses the straight wire design and the wire lies directly on the plastic housing then you should look to see if the wire has sunk into the plastic. This wire produces heat and causes the plastic to melt a little and the wire to sink into the plastic so the slider no longer makes contact. It may be necessary to replace the thermostat.

Thanks for the reply. This unit is 2002 therefore has the built in relay now on the board. I bought another thermostat entirely to test that out, but did not move the anticipator.

However...since I only have 6v going to the thermostat, I think that's the bigger culprit to look into.