How to wire Ruud Furnace

[OverkillYJ]

OK. I got gas and electric hooked up to this furnace my father in law helped hang in my roof Saturday. I picked this furnace up Friday morning for $70. It is a Rudd 100k BTU 90% efficient furnace. It was hooked up with an AC unit.

I have changed thermostats before, but I am not sure how to wire this. I do know I can fry stuff if I do it wrong though, so I am doing my homework first. I am familiar with a boiler setup furnace, and then the fan separated for the central air unit which I have wired in my home. I do not know what I do and do not need with this unit and only heat though.

Honestly right now I just want to confirm it works properly, then I will finish venting it and go buy the ducts I need. I bought the furncae from an older guy in his 70's off Craigslist of course who seemed pretty straitforward that he used it while building his house which he just finished. It heated an apartment/garage on his property. He said it worked fine when he pulled it and I believe him. Seemed like he just wanted to clear some space in his garage for a new bench he just bought.

It is now installed in a way in my roof that I can service it without ever having to take it down. The Gas was already run by the previous owner of the garage, so I just had to hook it up again. I put it on it's own 20 amp breaker with a new line run just for this yesterday.

I also have a digital thermostat new in the package somewhere, but I cant find it. I figure it will turn up as soon as I get it running with the old thermostat already in my garage.I have the standard regular t-stat with a red and white wire out there now. I have these two sets of wires coming out of the furnace. I assume the fan will bypass the thermostat? Or should I search high and low for the digital one I have that can control everything?

I will not be adding AC out there any time soon.

Any help you guys could offer would be awesome. After 20-30 min of googling I figured I would just create a thread. I get the best answers on this site anyway. If I need to take any more pictures let me know.

 

[sms1974]

All you need for heat is the R and W terminals on the control board. Connect them to the old thermostat that's already there and it should run. If you do put a digital thermostat on later you will need to replace the thermostat wire to at least 4 conductor wire, that will give you the ability to have heat and turn the fan on seperatly...

 

[mygarageone]

That is not a 90% eff furnace , it's an 80% unit. but for your purpose it probably doesn't matter .

 

[Ohmthis]

Overkill, get a four wire tstat cable and go ahead and run it to the furnace from you tstat location. That way you'll be ready when you add the digital tstat and or ac. And please, please don't run that without a flue/vent. You will fill up your shop with CO pretty quickly!!! To test it you can just jump the red terminal to the white in the furnace.

 

[OverkillYJ]

I already have the piping and everything for it the exhaust. It is that high efficiency plastic ****, and the furnace is 90% efficient. Of course I will pipe it out and put on some ducts as well as a proper return filter once I know I have it running properly with a thermostat hooked up.

Also, I meant to respond to this earlier. I get the blower to kick on when I hit the manual switch, but connecting the red and white wires, or using a jumper do not cause the ignitor to heat up or the blower to start. Basically, nothing happens. Kinda curious what the order of troubleshooting is on these.

Being a tech myself I have an order of troubleshooting everything I work on to make the process efficient, and also rule out cheapest parts first. Not sure what plan I should get together for this thing though. Any help would be appreciated.

 

[LS6 Tommy]

That is NOT a condensing furnace. A PVC stack on that is a big no-no & a potential fire...

Tommy

 

[brewchief]

That is NOT a condensing furnace. A PVC stack on that is a big no-no & a potential fire...

Tommy

This for sure, did it come with plastic vent? Maybe not pvc but some **** labeled ultra vent or plex vent? If so DO NOT use that vent, it is junk.


As far as trouble shooting I would start by seeing if I had power at R and C on the terminal strip, should be aprox 24 vac.

 

[OverkillYJ]

Alright. I will check for voltages tomorrow. And yes, this is the recommended vent that came with it (according to the guy who had been using it for years). It has a drain and things on it. If I didnt see this came with it I would have just vented it normal with metal. It is only 3ft away from 3/4" plywood that houses the large exhaust fan in my roof. I figured I would vent it out by cutting a hole right there.

Manufacturer part number on it is UGDE-10ERAJR. I cant find any info on it. That is what is on the sticker though.