Need a new thermostat

[micky]

Another problem with getting a heat pump is that the wirign to the thermostat is inadequate. no easy way to run a new wire to the same location**.

1) I know they make wireless thermostats and wifi thermostats, but I wonder if they made ones that are wired but can get by on only 4 wires, maybe by modulating the signal or something, and demodulating it at the furnace end.

2) Also, a much harder question: For years I've been looking for this, a setback thermostat that had a Next button. So if you come home early, leave early, go to bed or get up early, instead of having to use the up or down button and count how mnay degrees you set the temp up or down, you push one button once, to go to the next time period/temparature.

This seems so obvious I don't know why there aren't many versions of it. I think I saw one of these 40 years ago, but not since then.

3) **I could move the thermostat to a different wall, but it would be closer to the kitchen, by the doorway just on the other side of the wall. There is some heat from the refrigerator, and I use the oven for an hour every 2 or 3 days, and that warms the kitchen and I suppose would turn the heat down, while I was in the kitchen and for a little while afterwards. Of course when I'm in the kitchen, I don't care how warm it is is in the kitchen. It would also turn the AC up when the oven is on, and that would be a waste when for the rest of the house, but otoh, it's only 3 hours a week, and if it were really a lot, I could turn the AC off. The next owners may not like this, but they can buy their own wireless thermostat if that will make them happy.

[WWS TEXAS]

Tie the new wire to the old wire and pull it through?

[micky]

Good idea. I can't really try that until I know I won't need any more heat, and I'm guessing it's been stapled in place, though maybe the staples are not very tight??. Plus it goes down to the basement ceiling and back between the joists before it ge4ts to the laundry room with no ceiling. Maybe if I tug there I can get some hint as to whether it's stapled tightly in place. Well, the horizontal part must be stapled or it would get in the way of the guy putting in the ceiling. Right?

[Al Borland]

Unless you've got poured/concrete block walls, just run a new wire. Sheeesh!

[Clare Snyder]

Wont work if the original wire is stapled the way it is supposed to be - - - -

[Mark Lloyd]

I don't have a heat pump, but 2 stage AC and heat. This requires 7 wires (including power return) to the thermostat. I now have 10 wires installed (3 for later use).

I have seen one of those. It has a unit next to the furnace, and the connection to the wall unit works like USB USB (2 wires for power, and 2 for data). I don't remember brand/model.

My thermostat doesn't have that, just the manual override (temporary (changes to schedule at next scheduled time) or permanent).

[snip]

[trader_4]

[Clare Snyder]

If he's got pured concrete walls it's all in conduit so the's got it easier than most. (think before you post nonsense)

[Clare Snyder]

I have a 2 stage furnace plus AC running on 4 wires - using a single stage thermostat.

[Roger Oveur]

pured? the's?

Were you drunk when you posted that?  Sober up before you post.

[micky]

This looks like just what I need.

On this page there are mutilple models

says the 3000 only adds 2 control wires, while the 5000 adds 3 plus a C wire, and the 1000 adds 1 wire, and the Common maker adds a C, and 7000 and 9000 extend the wiring.

Instructions are provided for each of them to figure out which to buy. They sell them through Lennox stores, two of which are listed in Baltimore, plus the installer can get them too, i'm sure.

They list a bunch of other suppliers including Home Depot. But Home Depot just lists the Common Maker, at $41.

7000 and 9000 look pretty complicated, more than I need I'm sure. if I only had 2 wires to begin with I'd need the 5000, but I already have 4 or 5 wires, so the 3000 model is probably enough.

Amazon has it for about 20 more than other places, but it has 4 reviews.

of which were helpful. I think one guy thought he had to run all his signals through this, instead of using 2 of the 4 wires he already had that this device did not need.

[micky]

I'm not positive I ever saw one, but 40 years ago I'd just bought another setback thermostat, when they weren't very common, and I wasn't going to buy a second. I never came home early anyhow, and if I did anthing else early, I just let the timer work when it worked. Now I'm retired and have less of a schedule than ever, even sleeping weird hours.

Still, I looked again for something like this, and found one with a Next button, but sadly, the next button was for setup and like the others, it relied on up and down arrows to override the current setting one degree at a time.

I wonder if these are all the same because they all use the same "thermostat chip/IC" to control them.

[gfretwell]

The problem is, with a heat pump you need W1 and W2, that makes 5. One will start the heat pump compressor and if it can't make the stat - 10 degrees or something W2 kicks the heat strips on. You really need 2 wires for that (plus the hot, cool and fan). If you just want your furnace to be a single stage, that's OK but in Bal'mer he will need that toaster wire if he is not burning oil.

[gfretwell]

If you have 5 wires you are good to go without anything but a Mux will work too if you really only have 4. That is pretty rare T stat wire, make sure there is not another one in the jacket (cut off).

[Clare Snyder]

My 2 stage furnace has "smarts" built in that allow it to function as a 2 stage furnace with a single stage thermostat. If it has ti run longer than a certain time it kicks onto high. It id a Tempstar.

No reason a heat pump can't do the same. If when the heat pump starts it cannot produce a temperature rise of X degrees in a given time it turns on the aux heat. It's a pretty simple control algorythm

[trader_4]

Yes, if it's just one stage eqpt, seems you could do an oil furnace and heat pump on just 5. The one thing you'd be lacking would be a common wire so you could have the thermostat powered off the AC transformer. That's nice so you don't have to depend on batteries and you can have a backlit display that's lit up all the time. But if it's too hard to run a new wire, you can certainly live without it.

The bigger question for Micky is the economics of a heat pump vs oil furnace in MD. Also with AC it's nice to have two stage, but when I was looking ten years ago, those cost a couple thousand more. You did get higher efficiency too, but there would have been nowhere enough payback on electric to make the higher eff one worth the extra cost. And two stage is nice, but I don't think worth a couple thousand extra. Two stages in a gas furnace was only a few hundred bucks more, I got that.

[gfretwell]

I assume they could but I haven't seen one that did.

[gfretwell]

I chucked the "smart" thermostat when I retired. If I am home all day I am not interested in doing any set backs during the day. We never really used to do it anyway. The thing was running on "hold" most of the time when my wife wasn't fooling with it. I put a T87 in there.

[micky]

Good advice.

One of them looked at it when the topic came up but didn't say anything. He seemed to look at the wire two feet from the end, instead of at the end!!

Anyhow, it has a blue wire wrapped around the insulation and 4 other wires, so I gather I'm okay already.

(I was looking forward to buying one of those fancy muliplexers. Darn )

[Clare Snyder]

I believe the original "water furnace" did. I'll have to ask Dave if I see him (Dave Hatherton - founder of Water Furnace, was a highschool classmate of mine) I (as Energex R&D) had also worked on a conceptual basis on the technology in the early seventies and a simple timer, tripped by the call for heat, was considered as a way to call for aux heat if the outlet heat fromthe heat pump didn't reach a minimum setpoint. Simple "NAND" function. Timer expired and setpoint not reached, start aux heat. That signal ANDed to the thermostat signal to shut off the AUX when the thermostat stopped calling for heat and shut down the heat pump. I never got to implementing it but had figured out how many gallons per minute of water needed to be circulated from the wells, and all the other theoretical details.