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Reznor F75 natural gas heater


rootercycles's Avatar
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09-09-07, 05:22 AM   #1 (permalink)  
Reznor F75 natural gas heater

I have recently installed an old (1989) Reznor heater. It is natural gas and I have been able to get it up to the point of keeping the pilot light lit. It is a match light system. When I turn the selector knob to "on", nothing happens. I don't hear a change in gas velocity or anything else. The electriciy is on to the heater and the pilot stays lit. I recently had a heater guy install an in-line regulator. Before that, the gas poured out. How do I get this thing to fire? I haven't checked to see if the fan works, and the system is not hooked up to a thermostat. Those two wires are spliced together. I am trying to get this thing going before it gets really cold here in MN! I have also got more money in this thing than I originally planned, so I want to do as much as I can myself. I have looked online for a wiring diagram for the unit without success. HELP!

 
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09-09-07, 01:09 PM   #2 (permalink)  
Posted By: rootercycles I have recently installed an old (1989) Reznor heater. It is natural gas and I have been able to get it up to the point of keeping the pilot light lit. It is a match light system. When I turn the selector knob to "on", nothing happens. I don't hear a change in gas velocity or anything else. The electriciy is on to the heater and the pilot stays lit. I recently had a heater guy install an in-line regulator. Before that, the gas poured out. How do I get this thing to fire? I haven't checked to see if the fan works, and the system is not hooked up to a thermostat. Those two wires are spliced together. I am trying to get this thing going before it gets really cold here in MN! I have also got more money in this thing than I originally planned, so I want to do as much as I can myself. I have looked online for a wiring diagram for the unit without success. HELP!
There are plenty of wiring diagrams at reznor's website. Your unit should be fairly simple. The circuit should go from the the transformer [unless you unit is line voltage then there won't be a transformer] to a limit switch, then to the thermostat. then to the =ga svavlve, then back to the other side of the gas valve. So first thibng to do is check to see if you have voltage at the gas valve. If not, look for a high temperature limit switch and see if it's open.

 
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09-09-07, 01:45 PM   #3 (permalink)  
I recently had a heater guy install an in-line regulator. Before that, the gas poured out. How do I get this thing to fire?

Why did he do that???? didnt it have on on???? This unit wasnt on LP was it??? Did he set it and check itwith a manometer?????

 
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09-09-07, 04:12 PM   #4 (permalink)  
my heater

he put the regulator on because it didn't have one. He said that where I live the gas is under high pressure and needed to have a regulator on the unit. I don't believe he checked it with any meter. Regarding all of the information that daddyjohn submitted, I have no idea what most of that means. My electrical skills are limited when related to gas heaters. How would I decipher where the gas valve is? The unit does not appear to have a thermostat. I have bought an external one if that is what you mean. The wires that are connected to the thermocoupler are spliced together. Is that where the external thermostat goes? There are a couple of other wires (red) spliced together where it is connected to some sort of voltage regulator that then goes to the fan motor. I do hear a slight "buzzing" noise when I turn on the fuse to the system. I am a little wary testing the fan without the transformer or whatever reulator it is attached to so as not to burn it up with too much voltage.

 
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09-09-07, 09:01 PM   #5 (permalink)  
Do you have LP there or Nat gas?????? What does the unit say what kind of gas????

 
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09-10-07, 03:52 AM   #6 (permalink)  
It is natural gas. I hope to have this thing runnning soon. I think it is an electrical problem.

 
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09-11-07, 03:48 PM   #7 (permalink)  
Posted By: rootercycles It is natural gas. I hope to have this thing runnning soon. I think it is an electrical problem.

The gas piping going to the unit will go straight to the gas valve. On the side of the unit there should be a dataplate and also a replacement parts tag. Did you look at Reznor's website? There are installation manuals and parts manuals for your model there. The install manual has the wiring diagram you're looking for.

 
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09-12-07, 03:46 AM   #8 (permalink)  
are you saying this thing doesn't need a regulator?

 
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09-12-07, 01:53 PM   #9 (permalink)  
Posted By: rootercycles are you saying this thing doesn't need a regulator?

sorry foir the confusion- what I mean is if you follow along the gas piping, you can trace along it to the gas valve. I think the word straight may have confused you.

 
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