Honeywell RTH8500 installation

Jul 20, 2007 4 Replies

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snakedjip 19 years ago

Hi,

I currently have a Robertshaw 300-208 thermostat running my Luxaire heat-pump and (some other brand) electric furnace as auxiliary heat.

I just bought the Honeywell RTH8500 thermostat to replace it.

There are two labels on the Robertshaw thermostat which do not correspond to any label referred by the installation manual for the Honeywell thermostat : "24V" and "24V(c)".

I've included pictures of the current wiring. Because some of the labels are hidden in the pictures, here's a top-to-bottom list:

W1 Y1 G R

24V
24V(c) O B

Here are the pictures:

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Can anyone tell me which of my wires I should connect to which terminal on the Honeywell ?

Thanks.

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Noon-Air 19 years ago

Connect all of them

If you want to know where, my PayPal account is running kind of short, make a deposit, and I can tell you. Otherwise, call a local pro

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<kjpro 19 years ago

Have you tried Honeywells 800 number?

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Tekkie® 19 years ago

Only need one pix. I'm not even in the biz but I could do it. If I were you I would pull new wire because the Robertshaw wire isn't accurate for the Honeywell. Add an extra 20' on each end for expansion and contraction and the way the price of copper is going up I would buy it NOW!

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Bubba 19 years ago

Keeeeeeee-Rye-Min-EEEEEEEE again! "Im a tight ass. I bought a pretty new thermostat all on my own. I thought it would be soooooo easy. Who the hell needs one of those fancy expensive hvac techs?" Hint: Hook half the wires to the R terminal Hook the other half to the C terminal. Turn it on and watch EVERYTHING light up (for a split second). Then comes the fireworks and smoke because of the swell job you just completed. "Spank me, beat me, bite me". I dont even want your money in my Pay- Pal. Id rather just watch the fun. ..........and I havent even finished my first beer this evening. Bubba

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