I'm having problems hooking up my new thermostat and need an expert to assist me. I've done a major bathroom remodeling by myself, but always seem to get stuck on electrical items. Changing the thermostat is no different. BTW, the thermostat works, I simply want to change it due to aesthetics.

Background: I have Two Cadet in wall heaters, a Perfect Toe type floor model and a C122 wall unit.

I have a Cadet single pole thermostat, model # M411. (pictures attached)

I'm replacing it with a Honeywell RLV430A

Here's my problem... I literally melted the first thermostat I tried to replace it with and am now skittish. I did learn that the unit I was trying to install was NOT compatible with my Cadet heaters... lesson learned.

The Honeywell thermostat has only TWO wires coming from it. The Cadet thermostat has THREE wires coming from it. The Honeywell instructions gives me no clue how to hook this up.

The current wiring looks like this:

There are three "normal" household in-wall wiring looms (I don't know what the three wire strands are officially called) that must come one each from the heater unit and one must come from the fuse box. Each has a Black wire, a White wire and an exposed copper wire. In my description below, I will call wires from the Household in-wall wiring looms, "HH" wires.

Attached to the thermostat's red wire is ONE Black HH wire. Attached to the thermostat's black wire are TWO black HH wires. Attached to the thermostat's smaller white wire are all THREE white HH wires.

Oddly, all three wires attached to the thermostat seem Hot. I've tested them using a circuit tester showing voltage and one of those do-dads that simply detects a Hot wire. All three constantly show approx 120 volts, regardless of whether the heaters are actually running or not. I really don't understand this, but given the fact that the heaters seem to run fine, I won't question the Black Magic of electricity :-)

Given that the new Honeywell has only TWO black wires coming from it, how do I hook this up using this configuration?

Any help you can provide will be GREATLY appreciated!!

Happy Holidays!

Terron

Thermostats are fairly easy to install. However, before we get started, let's go through a basis safety check.

As a Maintenance Technician, when I do electrical installations I always trace the wiring. The reason I do this is because some time the colors of the wiring can show one thing and be another.

So this check is going to require for you to climb the attic (or whatever) and be sure there haven't been any wiring change. For example, one time when I was installing an outlet in the bathroom the wires to the vent was red; but when I looked into the ceiling, the original from the vent was green.

Changes like this happen all the time, especially when someone installed or repaired the unit while you don't know it. So, trace the wire from the wall to the heating unit and make sure the color codes are correct.

The basic home or building electrical wiring is white or red (+), black (-), and green or the exposed wire is the ground. By the picture you provided, you will not need the ground wire; the unit will automatically be grounded when you hook-up the black or (-)wire.

This seems to be your only trouble. However, if you need any additional assistance, please visit Honeywell's Technicals Call Wizard to guide you through wiring and troubleshooting your thermostat, as well as programming it to the most comfortable settings for you and your family.

Honeywell's Technicals Call Wizard
http://yourhome.honeywell.com/yourhome/Applications/Wizard/Wizard.aspx

Hope this answers your question!

EDITED BY: bkdaniels
12/26/2007

REFERENCE(S)

1. rpxlpx, Exposed Copper Wire (Online: Bobvila.com, 2000)
http://www.bobvila.com/BBS/Exposed_copper_wire-Electrical-1-T1390.html

2. From Wikipedia, Electrical wiring (United States) (Online: The Wikipedia Foundation, Inc. 2006) http://en.wikipedia.org/wiki/Electrical_wiring_%28U.S.%29
,

The basic home or building electrical wiring is white or red (hot), black (neutral), and green or the exposed wire is the ground. By the picture you provided, you will not need this wire; the unit will automatically be grounded when you hook-up the black or neutral wire.



The above is just plain wrong.

I think I have most of this figured out. Oh, and when I worked for a wire and cable company, we called things with more than one wire a cable. The individual wires were singles. The outer covering was a jacket.

OK the cable from the fuse, or more likely a breaker box, should have 2 hot wires of opposite phase, 120 volts above ground, but 240 volts to each other. Hook the black wire from the breaker box to the one wire of the Honeywell. Hook the 2 black wires that go to the heaters to the other wire of the Honeywell. Connect all three white wires together. Connect all the green or bare wires together and to the metal frame of the thermostat. There should be a green screw for that purpose. I am not sure why the old thermostat needed the white.

Bkdaniels' advice is wrong and dangerous. If it is a 240 circuit, neither the black or white is grounded anywhere. The third ground wire is an important safety feature including in 120 circuits where the white wire is a neutral grounded at the main breaker box. I find such posts by people claiming to be in the business appalling. Code strictly requires the ground wires to be connected to any metal frames or cases. It is a life saver, quickly tripping the breaker if a hot wire comes in contact with any metal you could touch.

If anybody doubts this, post a question in the electrical and lighting forum.

If this installation is in the US, and this is why it is so important that posters with questions provide their location, then BK, the information you have provided:



The basic home or building electrical wiring is white or red (hot), black (neutral),

Is absolutely incorrect, confusing the poster, and dangerous. If you are not absolutley sure of wiring, then you should not be giving advice.

In the US, and Canada for that matter, the basic color code for 120 volt wiring is:

Black is HOT
White is Neutral
Green or Bare is Equipment Ground

For 240 Volt wiring:

Any color, including white, now mandatory to be colored or labeled Hot, can be one of two Hot legs of a 240 volt circuit. White has been used for many years as hot for a 240 volt circuit, and just recently the NEC requires the white be labeled as HOT, so there are many homes with white being used as a HOT.


This statement confounds me even more:


the unit will automatically be grounded when you hook-up the black or neutral wire.

Since when is ANY Black is used as a Neutral?

You may want to refer to the reference YOU provided:




REFERENCE(S)
2. From Wikipedia, Electrical wiring (United States) (Online: The Wikipedia Foundation, Inc., 2006) http://en.wikipedia.org/wiki/Electrical_wiring_%28U.S.%29
,

From the above link:
The National Electrical Code specifies that the black conductor represent the hot conductor, with significant voltage to earth ground; the white conductor represent the identified or neutral conductor, near ground potential; and the bare/green conductor, the safety grounding conductor not normally used to carry circuit current. In 240 V applications not requiring a neutral conductor, the white wire may be used as the second hot conductor, but must be recolored (usually red) with tape or by some other method. Four wire cords have red as the fourth color.


Tlindy, seems the Cadet M411 stat is a single pole line voltage stat, however I cannot find it at their website, and may be discontinued, and I do not know what the white wire is for.

Single pole stats are allowed to control a 240 volt heater, as shown in the wiring diagram provide with your new Honeywell stat. You did look at that diagram?

I however do not like using these stats, as they will only break one of the two hot legs, and if the stat is off, there will still be one very HOT leg at the heater.

F you chose to use the Honeywell stat, you will need to find both legs of the Line feed into the stat, and both of the Load legs going to the heaters, splice one leg through the stat junction box, connect the remaining hot feed to Line wire/terminal on the stat, and the remaining wire going to the heaters to the Load wire/terminal on the stat.

Refer to the wiring diagram provided with the Honeywell stat, and if you are still not sure of something, please get back here with your questions.

You must be absolutely sure of what you are doing since you are now dealing with 240 volts, and as you can already see for yourself, it is unforgiving.

Thanks guys for the advice. More research proves, the first bit of advice from bkdaniels was in fact wrong. Although, I do appreciate the attempt to assist me.

The Cadet heaters are 240V. When I replaced one of them last year, I contacted Cadet directly and their seemingly odd advice was, "It doesn't matter how you wire them [black to white or black to black... actually, the units have two black wires coming from them]".

tkrussell, thank you for your sound advice. So am I better off keeping the old thermostat unit in place or do you have another recommendation for something other than the Honeywell I currently have? Again, there's nothing wrong with the operation of the current thermostat, albeit somewhat antiquated.

For your reference, the Honeywell model I purchased is what was recommended by Cadet for these units on their web site.

Again, thank you ALL for your help!

Happy holidays!

Terron

Thermostats are fairly easy to install. However, before we get started, let's go through a basis safty check.

As a Maintainence Technician, when I do electrical installations I always trace the wiring. The reason I do this is because some time the colors of the wiring can show one thing and be another.

So this check is going to require for you to climb the attic (or whatever) and be sure there haven't been any wiring change. For example, one time when I was installing an outlet in the bathroom the wires to the vent was red; but when I looked into the cealing, the original from the vent was green.

Changes like this happen all the time, especially when someone installed or repaired the unit while you don't know it. So, trace the wire from the wall to the heating unit and make sure the color codes are correct.

The basic home or building electrical wiring is white or red (hot), black (neutral), and green or the exposed wire is the ground. By the picture you provided, you will not need this wire; the unit will automatically be grounded when you hook-up the black or neutral wire.

This seems to be your only trouble. However, if you need any additional assistance, please visit Honeywell's Technicals Call Wizard to guide you through wiring and troubleshooting your thermostat, as well as programming it to the most comfortable settings for you and your family.

Honeywell's Technicals Call Wizard
http://yourhome.honeywell.com/yourhome/Applications/Wizard/Wizard.aspx

Hope this answers your question!

REFERENCE(S)

1. rpxlpx, Exposed Copper Wire (Online: Bobvila.com, 2000)
http://www.bobvila.com/BBS/Exposed_copper_wire-Electrical-1-T1390.html

2. From Wikipedia, Electrical wiring (United States) (Online: The Wikipedia Foundation, Inc., 2006) http://en.wikipedia.org/wiki/Electrical_wiring_%28U.S.%29
,


Black is never nuetral.

Bk, your editing of your original post:



Originally Posted by bkdaniels
The basic home or building electrical wiring is white or red (hot), black (neutral),

Is still incorrect, and does not even make any sense:



The basic home or building electrical wiring is white or red (+), black (-), and green or the exposed wire is the ground. By the picture you provided, you will not need the ground wire; the unit will automatically be grounded when you hook-up the black or (-)wire.
EDITED BY: bkdaniels
12/26/2007

Plus and minus does not apply to home wiring, as it is Alternating Current (Otherwise know as AC).

Line voltage Red or black wiring found in a home, or any other building for that matter, never means (+) or (-), which implies Direct Current,(otherwise known as DC).

This displays the fact that you are not understanding of the electrical trade.

Please stop offering faulty, incorrect, and irrelevant advice.

Honeywell is out today (12/26/06) so I'll call their tech support tomorrow. I'm REALLY big into reading drawings etc (I'm a mechanical engineer, but obviously, not an electrical engineer). Their otherwise well documented instructions only gives me two options for hooking up the wires, neither includes how to deal with the 3 wires which come from the original stat.

I was considering following labman's wiring advice, but if I blow up the stat (again) that's another $75 I eat.

This is kind of tough because I'm not exactly certain where the three 12G nomex wires, which come into the box for the stat, originate from. I did have the Cadet units out of their respective locations for the remodeling, but I put them back in similar locations, using the original wiring.

I'm assuming one nomex comes from the floor model, one comes from the wall model and the third, I'm logically guessing comes from the breaker box, located at the diagonally opposed corner of the house. I do recall that the wires at each Cadet unit were hot.

labman's wiring advice sounds good... perhaps I'll don a fire retardant suit and give it a whirl... I can't leave well enough alone :-) The worst thing that could happen is A) burn the house down (that's bad, right?) B) throw the breaker once I turn it back on (that's not so bad, simply tells me it didn't work) C) blow up the Cadet heaters or the fancy new thermostat (Bad again, right?)

If it works, I owe you both an adult beverage next time you're near Seattle. If it doesn't, check out the local news channels for the pretty fireworks some dolt created by trying to wire his house incorrectly :-)

Terron

Tkrussel has the final say on any electrical questions here. That is why I alerted him to this thread. The 2 pole thermostat he suggested adds a margin of safety. As he said, the single pole you have is approved as long as it is rated for 240. It sounds like the first one may have been a furnace thermostat meant for 24 volts. Oops!

With the breaker off, one pair of wires shouldn't show any conductivity - open, and with the breaker on, 240V between them, the feed from the breaker. The other 2 pair should a fair resistance between the black and white, the cables to the heaters. The bare or green wires shouldn't show any connection to any of the other wires. In a single pole circuit, 120 volts, the bare and white are connected back at the box. If you compare what I said to the diagram in the other thread, you will se the only difference is that the other thread has a 2 pole thermostat, and the white wires are switched to.

The good thing about an open forum like this is that when somebody posts bad advice, others see it and point it out. It is tough for me to pass by questions I feel I can give good answers, but in more and more areas, I am trying to leave them for people with stronger backgrounds since they have shown up. Of course we always have people more eagar to answer, than able.

I however do not like using these stats, as they will only break one of the two hot legs, and if the stat is off, there will still be one very HOT leg at the heater.


Am I correct in concluding that a 2-pole thermostat can't actually control a 4-pole electric baseboard? If there's still one very HOT leg at the heater, doesn't that mean the heater is always on? That's what happened when I tried to install a Honeywell RLV430 this past weekend. No matter what way I connected the two wires coming from the thermostat to the 4 wires sticking out of the wall, the heater was ALWAYS on, even if the thermostat said it wasn't. Am I way off here?

You break a circuit anywhere, no current will flow. However in a 2 pole circuit, break one leg, and all the conductors from the other breaker to the break in the circuit are still hot and current will flow if given a path. A single pole thermostat, wired up correctly, can shut off a 2 pole heater. But you want to keep you fingers away from the heating element. Break both poles, and the element and the wiring between the heater and the thermostat are dead.

You really don't have a 4 pole heater.

Ok, my terminology is wrong. I'm not sure about 2-pole vs. 4-pole, but what I'm trying to do is install a 2-wire thermostat into a 4-wire connection. Every way I tried it, the heater was always on, but never shut off. I know it's been stated on this website and even in this thread before, but does anyone have any detailed yet simple instructions for doing this exact type of thing?

Here's what I have: 4 wires sticking out of the wall: A black and a white with 240V running through them (tested with a multimeter), and another black and a white wire with no voltage running through them. I have 2 black wires coming out of the back of my new digital thermostat, and the instructions say, "The thermostat wires are not polarized; either wire can be connected to the load or to the power supply."

I think I've tried every different combination of connecting some wires together and attaching the rest to the thermostat, and some combinations obviously tripped the breaker. I'm no electrician, so I'm open to advice and suggestions.

Put your multimeter on ohms and check the pair of wires without voltage. They should read 15-20 ohms, 10 is OK if they are 10 gauge wire. Also check the resistance between those wires and the bare wire. That should be open, off scale. If so, connect the 2 whites. Connect one black to each of the thermostat poles. Post back.

Ok, I'm in a similar yet different scenario than the original issue. I'm trying to install the Honeywell RLV430 to replace an older dial thermostat.

The original thermostat has 2 black wires, one white, and a bare copper going to it.

My first observation is that there is no place for the bare copper wire on the back of the Honeywell.

One of the black wires is single as far as I can see, which is only a few inches. The other black wire is the result of two black wires coming together. The white wire comes from the joining of three white wires.

Do I join one of the Honeywell wires to one of the black wires, the other black wires to the other Honeywell wire, cap off the white, and cap off the ground? I would think the ground would go somewhere on the new unit but there's no place for it.

The unit has instructions for 2 and 4 wire but the 4 wire make no sense and are visual only, no useful written explanation.

http://www.innerseed.net/misc/t-stat1.jpg

http://www.innerseed.net/misc/t-stat2.jpg