I’ve not done much with replacing thermostats so I got a question here.
Owner wanted me to replace a Lennox brand round (w/mercury bulb, and yes I will dispose properly) thermostat with a Honeywell programmable model.
The old stat had a white wire on W, a green wire on Y and the red wire on Rc. There was a small jumper wire from Rc to Rh. The new Honeywell model did not have an Rh. It DID have a small jumper wire preinstalled from Rc to I forget which other lettered terminal but there was no Rh.
So I inserted the white wire into W, green into Y and the red wire into Rc. But with no Rh and no jumper duplicated, did I do it wrong?
If at first you don’t succeed, try using a hammer next time…everything needs some extra persuasion from time to time. -ME
Replies
There is this thing in the box, it is normally thrown out, but if you read it you will be amazed!! Directions, had the same problem a year ago, the do tell in the directions what to do.
I DID read the directions. Under the alternative wiring methods they don't even refer to the Rh jumper or what to do if you had an Rh jumper. And no I did not toss the instructions.If at first you don't succeed, try using a hammer next time...everything needs some extra persuasion from time to time. -ME
I was trying to help, maybe somebody who knows will come on and tell you. I remember I had to trial and error this to get it to work.
see if your heat will come on,thats what the rh is for,i think there should be a rh rc and a jumper connected. by the way if you burn up the furnace while following this i give a money back gaurantee.
if a man speaks in the forest,and there's not a woman to hear him,is he still wrong?
Seems to me that where the jumper goes is the manufacturer's concern. If instructions say wire W, Y and Rc, you should be golden.
Well first it depends if you hve the right thermostat or not.
What kind of heat? Does the AC work from the furnace transformer or does it have a separate one?
Is the heat and/or the AC mutliple stage. Is it a heat pump? if so dual fuel or aux heat?
Does the thermostat need both a hot and common connection for keep alive or will it live off a battery?
But with only 3 wires it appears to be a basic furnace with a common, heat call, and fan on.
The Rh an Rc is for systems that have 2 separate transformers.
If all you have is basic furnace and and the thermostat uses local batteries for keep alive then none of the other terminals are used.
Note that once you get past the basic 3 terminals they sometimes are labeled differently by different brands.
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
This is a basic Nat. Gas furnace with an A-coil and compressor. The AC seemed to be working fine when Ileft. I know Rh if for heat, that is what I'm kinda concerned about without the jumper.If at first you don't succeed, try using a hammer next time...everything needs some extra persuasion from time to time. -ME
Sounds like your fine too me, but your missing your fan wire. Wired this way, the fan will only come on with the AC or furnace.
You won't be able to run the fan by itself.
You should have a "G" terminal on your furnace that connects to the "G" terminal on the stat.
On the old stat there was no G wire.If at first you don't succeed, try using a hammer next time...everything needs some extra persuasion from time to time. -ME
On the old stat there was no G wire.
Yep, I understood that.
But if your customer is wondering why the fan won't come on by itself (and it didn't with the previous stat either)
It's that he is missing that wire.
I would strip back the sheathing on the control wire to see iff you have another conductor that you could use. 3 cond. wire is pretty rare I would think.
Ray
It is possible that this was a very old installation before AC became commonly in place. Then when AC was added some one just reconfigured the old cable.Just guessing..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
I agree.
I figure he probably has a 4 or 5 conductor cable and it was never hooked up.
But... just guessing also.
Ray