So, my house is not perfectly insulated, but it’s not bad. House is wrapped in Tyvec, all new energy efficient windows and doors, and the attic has some insulation in it. My furnace is about 8 years old, and works well (forced air).
I had an old style thermostat until last night, when I bought this guy:
I set it up using mostly the default settings, so it does 62 degrees at night, 68 degrees when I am home, and I set it to run on a 20 minute cycle (3 times per hour). After fiddling around with it, I noticed that it did come on every 20 minutes, but it stayed within about 3 degrees of the set temperature. The house would warm up to about 69 - 70 degrees, and then within 20 minutes, it would get down to 67 or so, where it would come back on again for about 5 - 8 minutes.
So my question, is this the best way to do this? It seems like the furnace is running quite a bit, but the temperature never drops that much. The house is very comfortable, but I don’t want to get slapped with a HUGE energy bill this year. Last year, with the old thermostat (but keeping it cold as hell) my bills were between 60 and 80 a month for gas (heat and hot water).
So my question, anything I should change on my setup to make it more efficient, and, how many times per hour / how long does your furnace run?
This is all a guessing game. Some people will argue different points of how to set it up, but in the end, you may just want to play with it for different months and see what your bill ends up looking like. Compare it to last year’s if the weather has been similar.
Also, I have the same thermostat. How did you set it so that it runs on 20 minute intervals?
In the setup, there is 5 intervals you can set (30 minutes, 20 minutes, 15 minutes, 12 minutes and 10 minutes). The 20 minute one was for furnaces 90% efficient and higher, so I selected that one.
Your thermostat really wont change anything in regards to how efficient your house and furnace are. It just makes it so you dont have to think about turning it down when you leave and go to bed. Never heard about it running on 20 min cycles. All the ones I have used run the furnace until the temp is reached then stays off until it gets back to the temp i set it at.
Every thermostat runs on cycles. If after 2 minutes the temperature falls below the target, it won’t run again until the next 20 minute cycle. It’s to make sure you don’t run it non-stop.
I am trying to figure out how often other people’s furnaces are running, so I can gauge if mine running a 3 times per hour is normal.
Did you have a window open or something? 3 degrees in 20 minutes is a lot of temperature loss when it’s 50 outside. On a 0 degree windy day your furnace will probably be running constantly.
That’s what I’m trying to figure out, I have nothing to gauge it by. I believe it was in the 40’s last night, but it was 3 degrees in 20 minutes. I don’t have any windows open, but I may have to hunt down more drafts / add more insulation in the attic
Seems like you answered your own question. 60/20 = 3 cycles per hour. Of course it could be less if your house had any sort of thermal efficiency. Did you ever have anyone do one of those “home energy assessments” that can show where you are losing energy?
#1 - Jay’s right that’s a lot of heat to lose in just 20 minutes.
#2 - Take that thermostat back and buy a model that works properly. It should work off a temperature deadband not a time interval. That’s retarded. That 3 degree drop in 20 minutes when it’s 50* out is going to be a 10* drop when it’s cold out. Your house is going to be cycling from 60-70 all winter, or else running the furnace when it doesn’t need to.
They’re supposed to run the furnace until you hit X temperature and then automatically restart the furnace when the temperature drops to X-Y, thereby maintaining a temperature of (for example) 66-68* when your setpoint is 68*.
That is what I thought as well. I have the same thermostat, and you set it by time of day and target temperature. I never saw an interval option when setting it up.
I’ve had several different types of programmable thermostats and never have seen any interval for how long it’s supposed to run for.
Focus people The question was how often does your furnace run, and it seems like for most it’s less than 3x per hour. Is that true? That will give me the advice I need to go forward with my home energy audit.
It seems like my heat is leaking out too quickly, but I still want to compare the furnace heat cycles to you all, so that I can compare.
–mark
---------- Post added at 10:17 AM ---------- Previous post was at 10:16 AM ----------
It’s now how long it runs for, it’s the minimal interval between heat cycles. It’s on like page 2 of the instructions!
That is how all thermostats work! The heat cycles thing is the minimal time between cycles. It’s 2 variables that must be present in order to have the heat come on. 1. the heat must be below the threshold 2. the heat cycle time must be past due. It’s a feature built into modern thermostats.
Mine varies depending on the weather. Right now with the upper 40’s and lower 50’s with light winds I’d say less than once per hour. And I haven’t even taken the screen out of my storm door yet.
It’s in the quick-setup guide, not the operating manual. What is the page where you found that, I can point it out in the other one.
But, that doesn’t really help answer my question at all. Can you guys please let me know how many times per hour your furnace kicks on. That is all that I want to know :tup:
---------- Post added at 10:51 AM ---------- Previous post was at 10:50 AM ----------
I’ll pay more attention tonight when I get home. I think it’s set to go from 65 to 70 at 4pm so once it’s got past that initial warmup I’ll keep track of how often it cycles.
The question was how often does your furnace run, and it seems like for most it’s less than 3x per hour. Is that true? That will give me the advice I need to go forward with my home energy audit.