I currently have a thermostat that does not have a C wire connection. I was given a smart thermostat that says it is designed to work without a C wire but in some cases one will be needed. I checked the circuit board on the gas furnace and there is a wire coming from the C wire connection. Will the C wire be in the wall behind the thermostat? Why would they have it going from the gas furnace but not to the thermostat? The gas furnace was installed in 2014. I assume the thermostat was as well (seems like a fairly recent model - Honeywell). The house from the early 70s.
Please post pictures of your wiring....... How-to-insert-pictures.
We need to see the wiring at the thermostat and the furnace board.
If you look at the wire currently on the C terminal..... you'll probably see that it goes to a two wire cable. The other wire in that cable would go to Y. That is going to the A/C condenser outside.
If you look at the wire currently on the C terminal..... you'll probably see that it goes to a two wire cable. The other wire in that cable would go to Y.
As I described..... you have two cables at the furnace.
One goes to the thermostat and one goes to the A/C condenser.
The four wire thermostat cable is....
Red - R
Yellow - Y
Green - G
White - W
The five wire A/C condenser cable is.....
White - C
Yellow - Y
Blue, red, green are spares.
If you look at the condenser cable.... you'll see three wires wrapped around the jacket. Those are spares since it's a five wire cable and only two wires were needed. To bad they didn't run the same wire to the thermostat.
Hi. The power switch, on/off power switch mounted to the exterior side of my furnace (not the breaker), is badly rusted. It's inside the house, in the utility room in my basement. Natural gas, 93% or there abouts, efficiency unit. It vents out the side of the house via PVC. The only other appliance is that area is a natural gas water heater vented thru the roof. There's no visible water or condensation inside or on the exterior of the furnace. The room is dry. There is a condensate pump that drains from the furnace to the home sewer waste pipe ( PVC from a bathroom on the floor above) via a flexible plastic tube which is not blocked. The pump drains. All were professionally installed several years ago and have worked flawlessly.
Back to the switch - the AC wiring is fed from the breaker box, located in another area of the basement. At the furnace the wiring comes down from the ceiling above (open basement ceiling, all work exposed) via a PVC tube to a metal, new-work electrical box housing the switch. The box is screwed directly to the furnace side. The switch is on/off just like your basic light switch but heavier duty rating. The box interior, the metal cover for the box and the switch itself all have some fairly severe rusting. But it functions fine. Heat and AC all work. The switch works. But why is it rusting?? It's been getting worse over time, as you might guess. No water/moisture apparent in the wiring or tubing. I want to get this figured out. I plan to finish reno'ing the place and hopefully sell end of summer or early fall this year. Thank you in advance!
I am new to the forum and am looking for advice on converting from oil to propane and eventually heat pump.
We recently brought a home in Riverhead, NY. It’s a 2 story 2500 sqft home with forced air heat and AC and a 40 gallon water heater.
Current System:
a. Oil tank developed a leak and needed to be replaced,
b. AC/furnace is about 5 years old – Rheem 4 ton AC with Rheem oil furnace (dual zone with humidifier
c. Water heater is over 20 years old and in need to be replaced.
Since we have to replace both the water heater and oil tank, we thought it would be a good opportunity to convert from oil. We are looking at 2 options
1) Replace the water heater with a tankless combi unit powered by propane and add a hydronic heat exchanger to the plenum and keep the existing oil furnace but only use the blower and the oil would be capped off
2) Replace the water heater with a tankless combi unit as above but replace the AC/Furnace with a AC/Heatpump. We will add a heat exchanger to the air handler as a backup to the heatpump since temperature can get below freezing during the winter.
Option 1 looks cheaper initially, but may cost more to run in the long run. Additionally, I am not sure if it’s legal to have a oil furnace capped off.
Looking for advice from this group on which option is best and if you have recommendation on equipments.
Thanks in advance,
CC From LI
06-10-21, 03:19 PM
