A/C Thermostat Help

ARFlyer

ARFlyer

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ARFlyer
Over the past few months our electrical bills have gotten out of hand. We use to average around $30 a month, but now we are averaging around $70.

I'm thinking our thermostat is going bad in temperature measurement department. We have an old style slider, mercury switch, thermostat in our apartment. To keep the upstairs bedrooms at 68 over this summer, we have had to put the thermostat on 60. Last summer, we only had to put it on 65-70 and it was 10-15 degrees hotter outside. Either the mercury switch is bad or the red setting slider has been misaligned.

To help anyone trying to give suggestions. The thermostat is located downstairs in-between the air return and main vent on the same wall. Which I have been told is a bad location.

My parents have a Honeywell digital thermostat that my dad said I can use, since they switched to WiFi based ones.
 
If the temperature measurement is wrong, you should be able to measure that with a thermometer, near the thermostat.

It sounds more to me like you have an air leak or someone in the house is leaving a window open. Have you checked the fireplace flue?

If the A/C can't keep up with the thermostat, it may need service.
 
I had it backwards. The temperature reads lower then actual. If I put the slider on 70, the thermostat on my bedroom clock reads 60.
 
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Sounds like a dying refrigerator to me. (first thought)

Or the A/C unit loosing effectiveness.
 
I've confused myself.

Right Now:

A/C Temperature Reading: 65ish
A/C Desired Setting: 68ish
Upstairs Temperature Reading: 60

P.S. I hate these thermostats that use the red flag indicators.
 
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ARFlyer said:
Dying refrigerator ?
Click to expand...

Refrigerator, thingy in the kitchen, uses a lot of power. Just like air conditioner they can loose effectiveness and eventually don't cool anything. If the fridge is running and running and running = $$$
 
bnt83 said:
Refrigerator, thingy in the kitchen, uses a lot of power. Just like air conditioner they can loose effectiveness and eventually don't cool anything. If the fridge is running and running and running = $$$
Click to expand...

Haha, I should have saw that coming.... :mad2:
 
Any rate. Anyone know how to fix the thermostat, so it will at least indicate correctly?
 
If I recall, I think there may be a screw to loosen and adjust, or a tang to bend to calibrate the mercury switch to a thermometer. The programmable thermostats for heat pumps and separate a/c and furnace systems are not the same, so bear that in mind if you take your parents up on their offer. We have a programmable, and it does save us some on the bill.
 
Well it's pretty typical for your electrical usage to increase dramatically given the fact that the average temperatures have been getting hotter and hotter with each month. Once the temp breaks your bill will go down.

$70/mo electrical isn't unreasonable if you want AC. How many sq ft?
 
The old thermostats never gave me any confidence with their accuracy. If you are hot, slide the deal or turn the knob until you aren't. Or get a new thermostat.
 
bartmc said:
Buy a new one. Get one you can program.
Click to expand...

I have the Nest Thermostat at home and the office.

LOVE LOVE LOVE it.... especially when I can make an adjustment from my iPhone/iPad
 
70 a month? I would be dancing if my electric bill was that low. In the summer I average $300 a month


Sent from my iPad using Tapatalk HD
 
The usage is above last years range for the same time period. The temps this summer have been cooler then the last two. So something is pulling more kilowatts.

So I can't use a heat pump thermostat on a gas furnace system? I believe my parents is a heat pump one. I'll pull up my wiring diagram I made when I helped dad change the system.
 
AggieMike88 said:
I have the Nest Thermostat at home and the office.

LOVE LOVE LOVE it.... especially when I can make an adjustment from my iPhone/iPad
Click to expand...

I actually got my mother to buy my father that for Christmas. However, two weeks before Christmas, the bedroom thermostat blew up during a storm. So my father unknowingly replaced the unit. The one he brought was the Honeywell Wifi unit and my mom returned the Nest thinking it was now useless.

I can't afford it or I would get it in a heart beat.
 
ARFlyer said:
I've confused myself.

Right Now:

A/C Temperature Reading: 65ish
A/C Desired Setting: 68ish
Upstairs Temperature Reading: 60

P.S. I hate these thermostats that use the red flag indicators.
Click to expand...

You can't blame the thermostat for the difference between upstairs and downstairs - it just controls the temperature at one spot.

If your temperature distribution between the floors has changed then you have a change in your air flow - one or more of those valves in the individual runners (usually where they come off the main duct) has been moved.

If it's just that you seem to be using more power to get the same degree of cool that you used to get, then your AC needs to be looked at.
 
Real dumb question but when was last time you changed the filter?
 
I have not had a power bill less than $90 since 1996. Jeez that is good.

If you have an electric water heater, ensure it is not leaking overboard.
Ensure you have no water leaks on the "hot" side.
Clean refrigerator condenser coil.
Have a/c refrigerant charge checked and coils cleaned.
Do you have a supply register directing air towards your cold clock?
Some digital thermostats can be used on hp's or a/c's.
 
ARFlyer said:
So I can't use a heat pump thermostat on a gas furnace system? I believe my parents is a heat pump one. I'll pull up my wiring diagram I made when I helped dad change the system.
Click to expand...

A heat pump thermostat turns on the compressor, air handler, fan and depending if it's heating or cooling, the reversing valve as well as supplementary aux electric elements, all in the same system.

A furnace/ac thermostat controls two separate systems pretty much by turning them on or off. They are two completely different animals.

The furnace/ac stat is usually a whole lot cheaper to buy. I think you can get a decent Honeywell programmable for around $30.
 
There is device that might be useful in your search to find your electricity leak...

Kill-a-watt http://www.homedepot.com/p/Kill-A-Watt-Electricity-Monitor-P4400/202196386

Iv'e seen stories about folks using a device to find electricity vampires about their homes. Sometimes things like recharging transformers or TV's in standby mode (you thought that was the off button) are still drawing electricity even though they are not in use.
 
Most heat pump thermostats ( not all ). Will work fine on a gas furnace with AC tied to it. It just needs to be wired and if programmable then programmed correctly.
 
Can I double up the Y and RH on the new Honeywell thermostat or do I need to split them off?

The unit from my father doesn't have RH and RC.
 

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RC has a jumper to RH, so that can go to R on the new panel. However, what's the blue wire on the Y?
 
You will need to look at the wiring diagram for the new thermostat. It can be found on the internet if need be. How it should be wired depends on the tsat and wether you have a one or two transformer system.
 
You need one of these then follow the directions carefully :rolleyes:

heat.JPG
 
ARFlyer said:
RC has a jumper to RH, so that can go to R on the new panel. However, what's the blue wire on the Y?
Click to expand...

That is a very basic/low amu tstat...

"The earliest surviving bimetallic strip was made by the eighteenth-century clockmaker John Harrison who is generally credited with its invention. He made it for his third marine chronometer (H3) of 1759 to compensate for temperature-induced changes in the balance spring."

R on the new one is 24V hot. Some older outdoor units had transformers, as well as some fairly modern mobile home systems and one needed both Rc and Rh. Your system just needs the one R.

Yellow energizes your outdoor unit contactor for cooling.

Like already mentioned it depends on the model of the hp tstat. We need a pic of the new tstat, its terminal strip and you will probably want the install manual too. You may have to have a "Common" or "C" terminal connected if it does not have batteries to power the relays on the tstat. You will need a fifth thermostat wire for this purpose, possibly your blue wire.

Also, always turn off all power to indoor/outdoor units when working on hvac systems.
 
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RV10-

Here is the back plate of the thermostat. If possible I would like to use this one since it was free. :D It is a Honeywell CT3611

Does the Blue wire going to Y on the old stat connect to Y, C, or B?

So far I have

G --> G
W --> W
RH/RC --> R
Y --> Y
Blue --> ??
 

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What terminal did the blue wire go to on your old one?

What terminal did the yellow wire go to on your old one?

If nothing, I would use that for common or C.

Ensure that no jumper is installed between Y and W1.
 
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RV10flyer said:
What terminal did the blue wire go to on your old one?

What terminal did the yellow wire go to on your old one?

If nothing, I would use that for common or C.

Ensure that no jumper is installed between Y and W1.
Click to expand...

Both wires went to the Y terminal.
 
That was very confusing. Only the yellow wire normally goes from tstat to outdoor unit contactor. Trace the blue and yellow to furnace and outdoor unit if you feel comfy.
 
RV10flyer said:
That was very confusing. Only the yellow wire normally goes from tstat to outdoor unit contactor. Trace the blue and yellow to furnace and outdoor unit if you feel comfy.
Click to expand...

Ok, so after some poking around I figured out what was going on. The yellow wire on the Y terminates on the backside of the tstat. The blue wire is actually the correct Y terminal wire. However, come to find out I don't have a C wire. Just W, G, R and Y.

So can I run a similar gauge wire from the new tstat C to the C terminal block on the furnace ?

The furnace is a Trane Gas Heater.
 
ARFlyer said:
Over the past few months our electrical bills have gotten out of hand. We use to average around $30 a month, but now we are averaging around $70.

I'm thinking our thermostat is going bad in temperature measurement department. We have an old style slider, mercury switch, thermostat in our apartment. To keep the upstairs bedrooms at 68 over this summer, we have had to put the thermostat on 60. Last summer, we only had to put it on 65-70 and it was 10-15 degrees hotter outside. Either the mercury switch is bad or the red setting slider has been misaligned.

To help anyone trying to give suggestions. The thermostat is located downstairs in-between the air return and main vent on the same wall. Which I have been told is a bad location.

My parents have a Honeywell digital thermostat that my dad said I can use, since they switched to WiFi based ones.
Click to expand...

I have an energy saving suggestion that isn't thermostat related. Get a misting hose unit and a Magnavalve the same voltage as your AC fan outside. Wrap the misting hose so it mists over the coils. Wire the Magnavalve to the fan and supply pressure water. When the unit comes on the valve will open and mist the coil with water greatly increasing the efficiency and cooling ability.
 
ARFlyer said:
Ok, so after some poking around I figured out what was going on. The yellow wire on the Y terminates on the backside of the tstat. The blue wire is actually the correct Y terminal wire. However, come to find out I don't have a C wire. Just W, G, R and Y.

So can I run a similar gauge wire from the new tstat C to the C terminal block on the furnace ?

The furnace is a Trane Gas Heater.
Click to expand...

Makes sense now.

Yes, you can purchase 18 Ga/2-conductor low voltage wiring from a local hvac guy or hardware store. OR...purchase 18 Ga/8-conductor like I use on everything and then you will have three spares.

Find the two wires that come into the furnace from the outdoor unit. One will be connected to your existing blue or "Y" circuit. The other goes to "Common" or C.
 
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