Line voltage thermostats.

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mdshunk

mdshunk

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I've been having tons of trouble the last few years with line voltage wall mounted thermostats, used mostly for baseboard heating. The calibration from the manufacturer is terrible, and it has caused me many, many callbacks. I've used many brands, trying to solve this issue, but mostly it's been WhiteRogers and Marley. I have resorted to re-calibrating the thermostats myself upon installation, which has solved the call back issue for now. Anyone else experiencing this problem? How have you solved it? Is there a known manufacturer and model of a non-digital line voltage thermostat that has a famously good calibration that is available in ivory or white?
 
I wouldn't know since we very rarely install electric heat around here. One would think that with digital technology today some company would have a digitally controlled line voltage stat. If not, maybe I need to market one.;)
 
infinity said:
I wouldn't know since we very rarely install electric heat around here. One would think that with digital technology today some company would have a digitally controlled line voltage stat. If not, maybe I need to market one.;)
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Yeah, they're certainly on the market. They are 4x the price. The trouble is that the regular one's have only recently (the last several years) started to have this out-of-the-box calibration problem. I do lots of service work, so line voltage stats are a truck stock item. Electric baseboard is still a popular option in my area for remodel and room addition work.
 
I know you asked for non digital recommendations. I don't have one. But how about the Aube digital stats? I've used some and will say they are very nice units. We retrofitted an apartment complex with them last year. Why the aversion to digital?
 
mdshunk said:
#1, price. #2, regular one's used to be perfectly fine, until recently.
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1. Agreed
2. Agreed

I use Aube stats almost exclusively (both line and low voltage) because they are the only ones I haven't had problems with. (yet)
 
I bought a fairly expensive digital low volt t-stat and no amount of tweaking the anticpator setting could make it work well.

I went back to a very basic Honeywell T-87 and it works much better.

I know the question was about line volt but my point is that a digital may not work any better.

The one I had could not keep a steady temp.
 
I have a digital honeywell for my toekick in my basement bath room and it works perfect, never a degree higher or lower, plus hey, it's digital! and it tells me the time!
 
I love the T87, too. Have 6 of them for my hot water heating system, along with sub-bases for the 2 cooling systems. It's simple and dead accurate. Cold? Turn it up. Hot? Turn it down. KISS

If I do electric heat, I usually use these with a relay. Unless budget dictates otherwise.

I do think the setback features of thermostats are not used prooperly by homeowners and therefore are useless. Probably counterproductive.

Again, though, I''ve had good luck with the Aube. My supplier carries the non programmable low voltage stat just for me. I don't think they make a non programmable line voltage stat.
 
For non electric heat t-stats I perfer the Invensys tstat, has humidity stat built right into it, plus add remote sensors and such... easy to program, comes with built in enery saving programs all set up out of the box...
 
stickboy1375 said:
I perfer the Invensys tstat,
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Invensys makes some really sophisticated control / management equipment and software for super markets.

The system we install and work on controls refrigeration, lighting, HVAC it also contains refrigerant and maintenance logs.

Sorry Marc I can't think of any line volt stats that are any good, many do not even have numbers, only 'warmer' or 'cooler'.
 
iwire said:
Sorry Marc I can't think of any line volt stats that are any good, many do not even have numbers, only 'warmer' or 'cooler'.
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Right... the 'el cheapo's have a "Comfort Zone". I thought about going that route, but most of the stats that exist as presently installed have actual temperature markings. Heck, I remember the old Emerson and Federal Pacific stats used in years gone by even had a thermometer on them (like the T87's you reference), that's how accurate they were. I started this thread half looking for a good stat, and half hoping folks connected with that industry would read this and get their act together. (For those guys, I will accept a personal apology by PM in leiu of an actual cash reimbursement for all the call backs).
 
For all the digital technology fans out there... let us not forget life is still mostly analog... in the case of digital thermostats they usually use a thermistor which changes resistance as the temperature changes, thereby changing the voltage and/or current being measured by a circuit which calculates a digital representation of the analog measurement.
 
in the case of digital thermostats they usually use a thermistor which changes resistance as the temperature changes, thereby changing the voltage and/or current being measured by a circuit which calculates a digital representation of the analog measurement.
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In the control systems I work on a T-87 T-stat would be considered a "DI" (Digital Input) It has two states, open or closed (0 or 1).

A thermistor that varies resistance in relation to temperature is considered a "AI" (Analog Input) as it will produce varying resistance values.

How accurately that resistances is converted to temperature will depend on the software and sophistication of the controller it is connected to.
 
line voltage stats

line voltage stats

i just put them in my own house and you are right on the money, they dont function well at all , i think a double pole switch and my body temperature would work better. Anyway , I called my supplier to see about calibrating them and they said if I did they would not accept them back or honer the warranty. I'm thinking about a low voltage Honeywell (which can be calibrated very easily) in conjunction with a double pole relay, but as mentioned previous , thats getting into some bucks. Jim B
 
DaveTap said:
For all the digital technology fans out there... let us not forget life is still mostly analog... in the case of digital thermostats they usually use a thermistor which changes resistance as the temperature changes, thereby changing the voltage and/or current being measured by a circuit which calculates a digital representation of the analog measurement.
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I'm not touting digital technology. Just reporting on my findings of what I've used.
 
jbelectric777 said:
I called my supplier to see about calibrating them and they said if I did they would not accept them back or honer the warranty.
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Calibrate them anyhow. I must have changed out 20 line voltage stats and I came to the conclusion that another one was no better than the one I just removed. I've had them as much as 15 degrees off right out of the box, with about 5 being the norm. I just calibrate them myself now, with no worry. In a double pole stat, one contact just makes and breaks at a very low temp (around 60) just to serve as a positive 'off' for that pole when you turn the stat the whole way down. The second contact is the operating contact, and is the only one you need to calibrate. For most brands that I've come across, that's the right hand contact. I make the cut in about 2 degrees above present room temp, which makes them just about perfect. A known good digital thermometer should be used in conjunction with this calibration procedure.
 
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I've never even thought about this as a problem before. I have always told customers that the numbers are not accurate, and only there for repeatability. Set the knob where you are comfortable.

I tell them that, if you're still a bit cold, turn it up a tiny bit and wait a couple of hours for the new setting to stabilize. Likewise, if it's a little too warm, back it off a bit. Remember the best setting.

If you think about it, every room layout, heat loss, air convection pattern, etc., is different, and even the best thermostat is only capable of maintaining the temperature where it is located.
 
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