Thermostat Wiring Question

**ltzpowerstroke** · 07-07-2005, 12:48 AM

Hi I have a Nordyne E2EB-015/split unit A/C 5ton. I installed a new thermostat this weekend (marked all wires and replaced them to their proper location) The new thermostat is looking for a "C" or common wire. I have 3 wires that are not being used and the opposite end of them (at the air handler) are not connected at all. Where is this "C" wire to be connected? Thanks in advance.

**Jultzya** · 07-07-2005, 01:15 AM

Does it not tell you in the instructions?

**hoozdis** · 07-07-2005, 01:35 AM

....have a C terminal at both ends

**Jultzya** · 07-07-2005, 02:42 AM

You mean, as in 'C' on one of these?

,

I'll stop now.

**ct2** · 07-07-2005, 11:50 AM

ya thats what he 's talking about. I can see it from here

get it

If the thermostat is looking for a "c" terminal it must be one of those Smart thermostats

where does the other end of the wire go? and what color wires are there?

**ltzpowerstroke** · 07-08-2005, 05:24 PM

Well I just hired American Home Maintenance (recommended by the inlaws / they service their unit) He did a complete system check, Does not know where the C wire goes, said is should be a black wire. He checked my outside compressor unit and said my compressor is about to go out. He said it was drawing 25.9 amps at 89deg temp, should be only 11 to 11.5. Does this sound right? Still no C wire hook up and now I need a compressor. Anyone recommend a good brand to purchase? Anyone know of a decent HVAC business in the Tucson Az area? I don't think I will be calling these people anymore. Thanks in advance

**smokin68** · 07-08-2005, 05:37 PM

Originally posted by ltzpowerstroke
Well I just hired American Home Maintenance (recommended by the inlaws / they service their unit) He did a complete system check, Does not know where the C wire goes, said is should be a black wire. He checked my outside compressor unit and said my compressor is about to go out. He said it was drawing 25.9 amps at 89deg temp, should be only 11 to 11.5. Does this sound right? Still no C wire hook up and now I need a compressor. Anyone recommend a good brand to purchase? Anyone know of a decent HVAC business in the Tucson Az area? I don't think I will be calling these people anymore. Thanks in advance

1. hire an HVAC company. The maintenance company is fine for cleaning the coils/filter changing.

2. The C wire should be BLUE.....not BLACK,standard color codes.

3. Have a pro check the compressor....you can't judge it on amp draw alone, might be poor voltage,etc.

4.If this system is an older one, consider a new condenser and indoor matching coil instead of changing compressor if it does need a compressor.

**ltzpowerstroke** · 07-08-2005, 05:58 PM

Thanks. I am looking at the Trane XL14i on their web site. How much more efficent are the highter seers? If I could cut my elect bill by 1/3 it would pay for itself within a five years. Thanks again

**craig1** · 07-08-2005, 06:40 PM

the maintenance guy doesn't know what he is talking about. 25.9 amp sounds fine for a 5 ton unit. i just installed a Nordyne 5 ton yesterday and i believe the rating on the nameplate was 28 amps.

as for the thermostat, most do not require a common terminal. thats why it was not connected. simply take one of the spare wires and connect it to the C terminal on the thermostat and connect the other end to the C terminal on the circuit board in the furnace. the C terminal on the board will already have a wire connect to it from your A/C unit. it is OK to connect two wires there.

**smokin68** · 07-08-2005, 07:05 PM

Originally posted by ltzpowerstroke
Thanks. I am looking at the Trane XL14i on their web site. How much more efficent are the highter seers? If I could cut my elect bill by 1/3 it would pay for itself within a five years. Thanks again

There's been alot of discussions here on this topic.Do a search on the this site and you'll find tons of info. If you have high electric rates, a hot climate, and plan on staying in your home for a while, the higher seers can make alot of sense.

**tpa-fl** · 07-08-2005, 07:26 PM

Originally posted by ltzpowerstroke
Well I just hired American Home Maintenance (recommended by the inlaws / they service their unit) He did a complete system check, Does not know where the C wire goes

WHOA! That right there is your indication to show him the door & hire a competent tech...while you're at it, you might want to recommend that your inlaws do the same depending on how well you like them. An incompetent tech can ruin a perfectly good system with ease.

**dhvac** · 07-08-2005, 07:42 PM

what kinda stat?
usually common does not get hooked up but if it is a power stealing stat you will have to hook it up
you should hire a compentant tech to hook it up or you may end up needing the unit repaired
if you have a split system the common is already in use you could still use it but i would have someone who knows do it.

**Jultzya** · 07-08-2005, 08:05 PM

Originally posted by ltzpowerstroke
Well I just hired American Home Maintenance

First mistake!

(recommended by the inlaws / they service their unit) He did a complete system check, Does not know where the C wire goes, said is should be a black wire.

Can be any color if wired correctly!

He checked my outside compressor unit and said my compressor is about to go out. He said it was drawing 25.9 amps at 89deg temp, should be only 11 to 11.5. Does this sound right?

Not at all...

Still no C wire hook up and now I need a compressor.

Not so fast! Hire a reputible HVAC company to service your system and give you a REAL evaluation!
Looks like you are about to be bent over and loaded like a shot gun!!!!!!!!

Anyone recommend a good brand to purchase? Anyone know of a decent HVAC business in the Tucson Az area? I don't think I will be calling these people anymore. Thanks in advance

Figures you are in Az... there seem to be a lot of hacks in THAT area of the US.

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