Installation of Honeywell RTH8500 thermostat - Wiring

[snakedjip]

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:

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

Thanks.

[CJT]

Follow the instructions that came with the thermostat. :-) The two connections you're concerned about are probably 24V power and common; if your Honeywell is powered by batteries or "phantom" power, they're probably not needed. If so, tape them individually with insulating electrical tape so they don't short to anything and don't worry about them unless you experience problems with the new setup.

[bud--]

Pictures! What a radical idea.

Robertshaw

24V is power to the control circuit 24(c) is the 24V common (like a neutral in a power circuit) R is 24V power to the switches in the stat - jumpered to 24V W1 connects to R for heat - 1st stage - heat pump Y1 connects to R for cooling - 1st stage G connects to R for fan O ??likely 2nd stage heat - electric heat

You don't give the terminals for the Honeywell but R-W-Y-G are standard. You may need 24V common to power the Honeywell control circuit - that is the blue wire. Orange is probably the Honeywell second stage heat.

As the temperature falls to the set-point for heat, R-W1 connect to run the heat pump. Maybe 2 degrees cooler R-O[probably] connect for electric heat.

(I didn't google either Robertshaw or Honeywell. With heat pump and aux heat the Honeywell very probably needs to include 2 stage heat.)

-- bud--

[<kjpro]

No

[bud--]

Try again.

You probably figured out connections except red and blue

Robertshaw Honeywell W1 white Aux & E Y1 yellow Y G green G R (& 24V) red R & Rc

24V(c) blue I believe this is not connected Honeywell runs off batteries O orange O/B B --- ---

The Honeywell installation manual, which you must have, is at

the Robertshaw manual is at

-- bud--

[<kjpro]

Uh, it&#39;s still NO and will continue to be no.

You probably don&#39;t know me or my profession, so why don&#39;t you go study for a few years and then come back?

[bud--]

You don&#39;t know me or my profession.

You give no advice and no indication of a problem with what I said. Very useful.

-- bud--

[<kjpro]

C will never be used for second stage heating. Is that hard to understand?

If you want me to tell the OP how to wire his stat... I&#39;ll need a deposit into my PayPal account. Would you like to donate the money for them?

[bud--]

My first post mislabeled O, not "C". I haven&#39;t worked on heat pumps for a long time. And I figured the OP should provide links to the stat data.

My second post said "C" is not used.

Is that hard to understand.

Then don&#39;t waste everyones time posting. The point of newsgroups is to provide useful information.

-- bud--

[<kjpro]

Ok, &#39;O&#39; will never be used for second stage heating either.

What&#39;s so hard to understand about the following statement?

You probably don&#39;t know me or my profession, so why don&#39;t you go study for a few years and then come back?

Or do you always like to guess and post inaccurate information?

[bud--]

What&#39;s so hard to understand about the following statement?

"You don&#39;t know me or my profession."

I am a master electrician. It has been a while since I worked on a heat pump. For several years I worked for one of several subs for a major heating company that mostly did furnace replacements and A/C adds to existing systems. I did all the A/C adds to existing zoned heat where the zones had to be defeated for cooling - ie where the many existing systems had to be figured out (which other contractors screwed up). I won&#39;t bore you with other information.

As I said in my previous post, I think an OP should provided links to relevant information. For my 2nd post I looked them up. The way newsgroups work is people correct the posts of others. You apparently are above posting useful information, like explaining the error in my

2nd post (which you claim is wrong).

-- bud--

[<kjpro]

I understand it just fine. What&#39;s so hard for you to understand that *you* don&#39;t know how to wire his thermostat?

Point? If you were so good at wiring heat pumps, you would have known that &#39;O&#39; wasn&#39;t for second stage heating. You should have known what it&#39;s for off the top of your head. I guess if you don&#39;t mess with electricity for a while you forget which is hot (black or white)?

It *is* wrong... listen up...

&#39;O&#39; is not for second stage heating.

[bud--]

[bud--]

What a surprise - still no explanation of the error in my 2nd post - which you said was wrong.

And no useful help for the OP.

And one useful sentence in 7 posts. But maybe that is a good record for a troll.

-- bud--

[<kjpro]

Look at the last couple lines in the previous post, Dipshit.

Here, I copied it for you, since you&#39;re having trouble finding it.

QUOTE:

It *is* wrong... listen up...

&#39;O&#39; is not for second stage heating.

END QUOTE

[bud--]

Look at what I said dipshit.

Here, I copied it for you, since you&#39;re having trouble understanding it:

QUOTE:

What a surprise - still no explanation of the error in my **2nd post** - which you said was wrong.

END QUOTE (emphasis added)

O as second stage heat was in my 1st post. My 2nd post makes no mention of "second stage".

Note the difference - 1st, 2nd.

2nd follows 1st for most people. Perhaps wikipedia has an article that would make it clear.

And still no explanation of the error in my **2nd post** - which you said was wrong.

But whatdaya expect from a troll?

-- bud--

[trader4]

For the OP, since it sounds like you have 24V available at the thermostat, I believe on that model if you have 24V and wire it up, the thermostat LCD display will remain backlit all the time. Otherwise, with battery it only lights when you touch it and then remains on for 15 secs or so.

[<kjpro]

The following QUOTE is your *second post*.

See where *O* is listed? See where I posted NO? See where you posted, Try again?

Did that not pertain to me saying NO?

What are you, incompetent?

BEG>> O ??likely 2nd stage heat - electric heat

Try again.

You probably figured out connections except red and blue

Robertshaw Honeywell W1 white Aux & E Y1 yellow Y G green G R (& 24V) red R & Rc

24V(c) blue I believe this is not connected Honeywell runs off batteries O orange O/B B --- ---

The Honeywell installation manual, which you must have, is at

the Robertshaw manual is at

-- bud--

[bud--]

What an idiot, using a quote from my 1st post that appeared in my 2nd post and was obviously abandoned. You probably work for Alberto Gonzales.

But trolls don&#39;t like to admit they are wrong.

And trolls don&#39;t like to give useful information - useful information to OP - still zero.

But why expect anything else.

-- bud--

[<kjpro]

Then why did you disagree with my post? I said your information was inaccurate, then you post "try again". That says you disagree with me posting "no", did it not?

Didn&#39;t see me posting crap that wasn&#39;t true... unlike yourself, Dipshit.