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HVAC Forums => HVAC Help => Topic started by: The Mad Greek on November 03, 2012, 12:02:47 PM

Title: Unit heater wiring question
Post by: The Mad Greek on November 03, 2012, 12:02:47 PM
I have a Reznor UDAP 60 unit heater along with a White Rodgers (Emerson) 16E09-101 stat. I am having some difficulty with the wiring. Any help would be greatly appreciated.

I have R, C and W1 options on the unit heater
I have TR, TH, LOAD, LINE, NUETRAL AND NC on the stat
This is a low voltage installation

Schematics found below...

http://www.emersonclimate.com/Documents/White-Rodgers/instruction_sheets/0037-6857.pdf

https://www.rezspec.com/catalog-udap.html

Thank you in advance for any assistance
Title: Re: Unit heater wiring question
Post by: Admin on November 03, 2012, 10:08:39 PM
Install a jumper wire on the thermostat between LINE and TR.
Wire the thermostat LOAD to the unit heater W1.
Wire the thermostat TH to the unit heater C.
Wire the themosat TR to the unit heater R.

Make sure the SW1 is set to heat.
Title: Re: Unit heater wiring question
Post by: The Mad Greek on November 03, 2012, 11:59:08 PM
Thank you very much for the quick reply!

I tried the instructions you had provided but with no success. A couple things I should mention:

The gas valve is in the ON position
The unit is being powered with the method described below but no fan, call for heat, spark, stat not energized, etc.
I made an error in my initial post: the C I mentioned should have been G
The stat is set for HEAT
The stat is also set for NON POWER STEALING

Any suggestions would be appreciated.

Thank you in advance,
Ted.
Title: Re: Unit heater wiring question
Post by: Hgye on November 04, 2012, 09:59:48 AM
It looks like the stat requires 110v to operate.
Title: Re: Unit heater wiring question
Post by: Admin on November 04, 2012, 10:33:01 AM
It's different than any thermostat I've used, but the manual has a wiring diagram for a Non Power Stealing 24 VAC application.  It looks like that thermostat is not compatible with a Power Stealing 24 VAC application.

You need the common wire.

According to Page 23 in the Reznor UDAP manual there is a R, W, G, C and Y terminal block,

Reznor UDAP Version B (http://www.hvactechgroup.com/files/ReznorvB.pdf)

Here's an older manual I found that doesn't show a Common terminal at the Reznor,

Reznor UDAP Version A (http://www.hvactechgroup.com/files/ReznorvA.pdf)

You might be able to connect the thermostat common to the BR wire on the common side of the transformer.
Title: Re: Unit heater wiring question
Post by: MARK C on December 25, 2012, 07:41:15 AM
You are using a very expensive t-stat to operate a reznor unit heater, my first suggestion would be to put that on the shelf until you can sell it on the next commercial application that it fits, but hey if that's what you have, it will work. The Reznor only needs the low voltage hook up onthis unit "TR" to "R" AND "TH" to "W". If I am not mistaken these low voltage connections are dry contacts and that is all you need.
All the best
MARK