Need a manual for Reznor unit heater UA 40 - Heating & Cooling

check the hose to and from the pressure switch are not split . Check the snap disks there should be two . Fan should shut off on temp fall ,

Try turning the power off to the heater then turn back on this may reset the heater .

Brian, it is a very simple task to perform but for a novice YOU MUST HAVE THE POWER OFF !!!!!!

At Harbor Freight you can buy a cheap digital multimeter for about five bucks. After turning off the power, remove one wire from the thermodisc and use the resistance scale to check continuity. If it reads no continuity, the switch is OPEN and bad. If it reads continuity it is CLOSED and is good.

If you have a system that is not heating, did you check the top right side (facing the unit) of the Reznor heater for a 'manual reset' hi-limit switch ?? If not, do that first and listen for an audible 'click' as you depress the little red pushbutton. If you hear a click, turn the power back on and set the thermostat setpoint above room temperature and see if the heat now comes on.

If the flame is rolling out of the heater then the burners of heat exchanger is blocked needs cleaning

I'LL SEE WHAT I CAN FIND FOR YOU.

Have the pilot cleaned and serviced

Check your ground. If this is a spark igmitor clean surface of ignitor. Rus

Your fan switch is most likely bad. Need to replace.it with a new one. Not hard to replace just take old one to a AC supply house and they will match it. Or go on line to Reznor and they will have it, Just need the model number of unit. Rus

Don't know what model Reznor Waste Oil heater you have but I happen to own a Reznor RA235. 235,000 BTU. If there is no oil being pumped up I would first check to see that the filter isn't clogged where the oil sucks up from the tank. There should be a gauge on yours with different color codes as to when the filter must be changed or cleaned. I already had to replace the pump on my Reznor RA235 as the pump went bad a couple of years ago. You can tell if it is pumping or not. There is also a filter built right outside of the pump on mine and one up on top of the unit that need to be cleaned at times. The manual shows all of this.