A friend installed a Honeywell 5+2 Digital Thermostat last weekend. The inside temperature reads 68 and I am trying to check its accuracy. I compared it to two free standing digital thermometers which I balanced on top of the thermostat (at the same time). The thermometers readings range from 69 and 71; to 71 and 71. Any suggestions on determining the *right* temperature are appreciated.
Thank you in advance.
On Sat 11 Oct 2008 03:22:40p, allanc told us...
I have an "antique" alcohol bulb thermometer (which I know to accurate), mounted next to our digital thermostat. They are spot on with each other.
Find a callibrated analog thermometer and compare your thermostat with that.
If you don't have fever put them in your mouth
Where do I find a callibrated analog thermometer that I do not have to 'buy' in order ro check my thermostat?
On Sat 11 Oct 2008 04:21:02p, allanc told us...
Beats me. I don't know any place that's giving them away. I inherited mine, but would buy one if I felt I needed it.
Not necessarily accurate. Not everyone's body temperature is 98.6°F.
On Sat 11 Oct 2008 04:13:43p, Old and Grunpy told us...
So, what does the average person do that buys a thermostat?
For openers make up a mixture of ice and water. Before the ice is all melted check the water temperature. 32F right?
With a normal household thermometer you won't be able to check the boiling point, but the cold test will tell you if the glass is in the right position against the scale.
One of the digital thermometers ranges from about 66->86. I do not know about the other. Are you suggesting that I submerse the other? I have no idea if it is waterproof.
On Sat 11 Oct 2008 04:57:22p, allanc told us...
The "average" person probably doesn't give a damn about a 2-3 degree difference.
In fact, thermostats (either analog or digital) that automatically switch from heating to cooling depending on demand, usually have a 2-3 degree variance or threshhold for that changeover.
If it's that important to you, fork over the money for a calibrated thermometer and check and calibrate your digital thermostat. If the money bothers you, take the damned thing back after you've used it.
Is there a difference between the digital thermometer reading on your thermostat and the digital setting? They are independent of each other.
Sorry, did not mean to upset you. No, the reading and heat setting both are the same.
On Sat 11 Oct 2008 05:15:36p, allanc told us...
You didn't upset me. If I understand correctly, one of the digital thermometers you're testing with is matching the one on your thermostat. One does not match. That's two out of three. I'd go with that and forget about it.
As an aside, I was trying to find an accurate oven thermometer. Looking at them in the store, there weren't any two that showed the same reading. (These were bi-metal spring type thermometers.) I bought five of them, knowing that I might return at least four if not all of them. When I tested them all in the oven, I still got five different readings. I ended up taking them all back and buying a glass tube/bulb thermometer that was guaranteed to be accurate withint +/- 1 degree.
ide quoted text -
I didn't explain the standalone digital thermometers properly. Sometimes they read the same 71/71 and sometimes not 69/71. I am looking at them right now as they are on my desk. One is 71 and the other is about 72.
When they were on top of the thermostat - they both had higher readings.
One of them is 'progressive' in that the possible temps are on a horizontal display (66->86) in even digits. The current temperature becomes visible as it changes to green. When the temperature is 'odd' (eg 73), both 72 & 74 will be visible. Right now, 72 is green, 74 is light brown and 76 is darker brown. Makes no sense to me. I don't know how else to explain the thermometer and can not think of what the technology is called... LED possibly? I would think that my other digital is also LED.
Make ice cubes out of distilled water. Make a mixture of ice cubes and distilled liquid water, and shake it up good. When you're sure it's all 32F, soak the thermometers. the one which reads 32F is correct. The others are not.
Only an engineer could spend so much time on two degrees.
Nevermind the expense. What is truth worth to you, man!
Turns it up and down to find a comfortable temp, and then no one cares what the number is that makes for comfort. The average person replaces the thermostat four or five times when the furnace stops putting out heat. "After all, it's got to be the thermostat". and then calls the HVAC pro.
Reminds me, I did get such a call about two years ago. Some friends of mine had replaced the thermostat four times before calling me. The problem was actually unrelated.
Total submersion is the only accurate test.
you do know that heat comes out of the thermostat. so putting a thermometer on top will not give accurate reading. my bad, dumb question. obviously you dont or u wouldn't put it on top.
You are right. I never thought of that.
When we moved in here, the mechanical thermostat was off by about 8 degrees. We would set the heat for 68 and be sweltering.
Right now, these 2 standal> you do know that heat comes out of the thermostat. =A0so putting a thermo= meter
That's a good point. Another would be that various electronic units have different thermal mass, i.e. they take longer or shorter times to warm up or cool down. For instant reading a small thermocouple will give the fastest response .... but don't stand close to it or it will be reading heat radiating from your body.
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