Heater Thermostat November 25, 2020, 01:27:34 pm I went out behind my office building this morning and when I walked by my LD I could hear something running. It was the heater outlet blowing hot air. The last time I was in the LD was a week ago and I had turned on the heater, so thought that I had left it on. I went inside and the thermostat was totally off, in the far left position. So I moved the thermostat over to the right and back to the off position and waited, but the heater kept running. So went outside on turned off the propane and the heater shut off and fan stopped running after a few minutes. So I turned propane back on and went inside to cycle the thermostat. The heater remained off and when I moved the lever over I could hear a solenoid click and the heater came back on. This time when I moved lever to left the heater did turn on and finally fan shut off.I dont know how long the heater had been running, but the coach was warm, not hot, and outside temp was 40F. The propane tank was at 2/3 full so it couldnt have been too long. In any case after searching the records on the forum, it seems like a lot of folks have put in new digital thermostats. Are there any recommendations?
Re: Heater Thermostat Reply #1 – November 25, 2020, 02:04:44 pm My mechanical thermostat, older, about 1999, and a different model, slides a thin wedge shaped piece of plastic between the contacts when placed in the 'OFF' position. Those red and white wires are the only communication between the thermostat and the heater. So a malfunction is either the thermostat wasn't truly in the open (off) position; the wires, a twisted pair, have a short somewhere; or the heater internal relay, inside the heater, stuck in the closed position. I don't totally trust electronic thermostats. My house one kept the A/C running. Changed the batteries, still running...unplugged from baseplate attached to wall, stopped. Plugged back in with no batteries and A/C running again. Banged the entire thermostat on the counter, to dislodge the mechanical relay contacts, that must have stuck together, and it has been running fine for months. (New spare thermostat stored in garage next to heater/AC). So that can happen to fancy thermostats too. (It was only a few years old, minimal use) A friends MB, I replaced his messed up electronic with a new mechanical thermostat. Home Depot had it. Works fine. https://www.homedepot.com/p/White-Rodgers-M30-Heat-Only-Non-Programmable-Thermostat-M30/204804203#product-overview Now if you want a digital display, backlight etc, then others will have recommendations. RonB 1 Likes
Re: Heater Thermostat Reply #2 – November 25, 2020, 03:02:35 pm Anything simple will do. On my Mid-bath, I had limited space because the thermostat is mounted next to a magazine rack. Choices were limited and I ended up with a slider switch on the side that is a little hard to reach.In an area like mine, where heat pumps are very common, most (all?) thermostats at the big box store will also control A/C. It's no problem to ignore that part of the system and just wire up the heater. I think this is the successor to the model I purchased:TH1110DV1009 - Honeywell TH1110DV1009 - PRO 1000 Non-Programmable, 1H/1C,...There is a similar heater-only model:TH1100DV1000 - Honeywell TH1100DV1000 - PRO 1000 Non-Programmable, Heat...Rich 1 Likes
Re: Heater Thermostat Reply #3 – November 25, 2020, 04:00:37 pm Rich, a little guessing here. You found the inside to be warm but not hot. That suggests to me that the temperature portion was working. Sliding the control all the way left, when it resists a bit, that is the lowest temperature setting. To turn it off, you need to slide it past that spot until it snaps or clicks (by feel, not by sound) into the off position. I assume that you did that.Mechanically, there are two key elements. The top control is the off-on and temperature adjustment. As Ron said, if that control is truly in the off position there is a short somewhere. My bet would be that it is in the copper strip between the red and yellow wires. A short between the red and white would have the furnace running constantly, and it would have been hot inside, not warm. The second element is below the tan circle, under the translucent plastic cover. That is where the contacts for the temperature adjustment are. It sounds like that part is fine.My suggestion is, before replacing, look for something that might have gotten into that copper strip to somehow bridge or short from the red wire to the copper strip. If you see no deformation, nothing there that could short it out, replace the unit with a simple mechanical thermostat. Why try to fix rather than replace? The better you know your equipment, the less likely you are to have a problem that you can't handle while out in the middle of nowhere. If you can fix it, you know your equipment better. If you break it, nothing lost. You need to replace it, which is where you are right now.Ken F in NM 1 Likes
Re: Heater Thermostat Reply #4 – November 25, 2020, 04:27:18 pm "Sliding the control all the way left, when it resists a bit, that is the lowest temperature setting. To turn it off, you need to slide it past that spot until it snaps or clicks (by feel, not by sound) into the off position."----When I read Rich's (parussky) post, I wondered if the control had been "snapped" into the OFF position or just pushed to the far left; I started to post this question, but got sidetracked. Thanks, Ken, for the reminder that the thermostat needs to be "clicked off to be off"!
Re: Heater Thermostat Reply #5 – November 25, 2020, 04:57:10 pm A few more details on that left picture that Parussky provided. The copper bar at the top attached to the red wire (note R mark) is above the underneath copper contact where the yellow wire is attached. They are connected where that dimple is in the top piece. The temperature adjust lever probably has that plastic wedge, and separates the circuit when turned off so no current can flow. The yellow wire goes to the fixed contact on the left at the bottom inside that translucent cover. The white wire comes into the slider on the brown disc. The shiny mark at about 11:00 is where it has spent the most time. That device is called an anticipator. The circle is an adjustable resistor. It powers an electric heater placed next to the temperature coil, a spring made of bimetal that uncoils when hot and shrinks back when cold. The temperature set lever is attached to this bimetal device and the whole thing rotates back and forth. The other end of this coil has the movable contact on it, that turns the heater on and off. These contacts are hard to see through the translucent cover at bottom. Heat in the room operates that spring, but to avoid overheating each cycle, some current flows through the anticipator heater and by expanding the thermal sensor spring, opens the contact early. Sometimes this is called the hysteresis control. These covered contacts at the bottom are coated with precious metal. They can be cleaned with alcohol if needed. Gently to not affect the alignment. The anticipator rotating contact can adjust the cycle time. Presently set for slowest response, clockwise for rapid response. It can cause rapid on/off cycles if set too far clockwise, and too many degrees between cycles if it is too far counter clockwise. (picture: Heater Thermostat Sometimes people have trouble when the heater won't come on. A small piece of rough paper slid between the two copper bars (maybe some windex to wet it) can clean that area to make a better connection. Hope that helps understand what these parts all do. RonB 4 Likes
Re: Heater Thermostat Reply #6 – November 25, 2020, 05:05:35 pm "A small piece of rough paper slid between the two copper bars can clean that area..."Try a new crisp $ bill! Any denomination will work but the higher the denomination the better the job. Kidding of course! 2 Likes
Re: Heater Thermostat Reply #7 – November 25, 2020, 06:27:57 pm I installed the same heat only Honeywell as Rich referenced about a year ago and it is working just fine for me too.Matt
Re: Heater Thermostat Reply #8 – November 26, 2020, 02:10:44 am Thanks Rich, that was a nice looking thermostat that would fit well. But I'm used to the old one for now, pretty simple. RonB
Re: Heater Thermostat Reply #10 – November 26, 2020, 11:25:58 am If I may ...... got to love it. As mother always said you get wisdom by learning from experience.Furnace Issueglen
Re: Heater Thermostat Reply #11 – November 26, 2020, 02:01:37 pm You know, we have seen a LOT of posts about furnaces that would not start or would not heat. I think this thread is the first one about a furnace that would not turn off.Ken F in NM
Re: Heater Thermostat Reply #12 – November 27, 2020, 03:32:22 pm We put in a programmable one years ago Honeywell programmable thermostat because we wanted that feature (old mechanical original one still worked fine). We just grabbed what our big box store had in stock, it has worked fine and similar to ones we have used in houses. We ignore the Air Conditioning part of this.
Re: Heater Thermostat Reply #13 – November 27, 2020, 05:07:11 pm At least you were not the first to find out that it is absolutely necessary to slide the heater switch completely to the left. Until you feel it click.Confession. I did it when we first got our LD. Bong! Cheers!Tony R (aka codefour)
Re: Heater Thermostat Reply #14 – March 21, 2021, 02:56:23 pm I just discovered my OEM furnace thermostat has the "broken triangle" problem (see this thread from 4 years ago Furnace Issue ). You can see the triangle stuck in the grease. if you look carefully. Would like to upgrade to a digital unit (heat only). Any other suggestions for a replacement that uses the same wires as original?Would this problem keep the furnace from not turning on at all? Tried to start it this morning and nada.
Re: Heater Thermostat Reply #15 – March 21, 2021, 05:40:20 pm "Would this problem keep the furnace from not turning on at all? Tried to start it this morning and nada."In your photos it appears that the triangular tab is clear of the copper contacts on the left. If so, it could not be preventing the furnace from turning on. However, if those contacts are dirty or oxidized, that could prevent the furnace from turning on. You can test for this by bridging the red wire at top left and the yellow wire coming off the lower copper contact, with the thermostat set to its highest setting.Oxidation is also possible at the thermostat contacts, which are under the translucent plastic cover at the bottom of the unit. I'd suggest cleaning both sets of contacts.Now the question is: can that triangular tab be repaired? Give its flimsy construction, I can't think of a good way offhand, so a new thermostat may be the best long-term solution. In the short run, if you want to prevent accidental furnace startups, you can cut a strip from a plastic milk carton and slip it in between the copper contacts.It occurs to me that even cheap ten-dollar earbuds have gold-plated contacts on their plugs, to prevent corrosion. If they can afford to do that, why can't thermostat makers? I guess they just figure that nobody will notice, since unlike with earbuds, the thermostat's contacts are hidden inside. The user won't see them... until the thing stops working. Grrr.
Re: Heater Thermostat Reply #16 – March 21, 2021, 06:04:44 pm Quote from: Andy Baird - March 21, 2021, 05:40:20 pm"Would this problem keep the furnace from not turning on at all? Tried to start it this morning and nada."Now the question is: can that triangular tab be repaired? Give its flimsy construction, I can't think of a good way offhand, so a new thermostat may be the best long-term solution. In the short run, if you want to prevent accidental furnace startups, you can cut a strip from a plastic milk carton and slip it in between the copper contacts.Thanks, Andy. I’ll try “jump starting” it to see what happens. I did pull the fuse so it shouldn’t start up on its own correct? Which raises another question for this electrical dummy: when I reinstall the furnace fuse, do I need to disconnect the house batteries first?I am going to replace the thermostat, hopefully with a digital version. My understanding is that “heat only” thermostats only have two wires to connect, correct?
Re: Heater Thermostat Reply #17 – March 21, 2021, 06:25:47 pm Hi Greg,When you say the furnace wouldn’t start, I would like to know if you heard the furnace fan start when you moved the white thermostat switch to the right (from off). If so did the fan turn off shortly after starting and the furnace would not light producing heat through the vents?If the fan did start then turn off, you may want to insure that the propane tank valve was turned on. I had this issue two weeks ago and found that I had not turned on the propane. Even though my fridge lit as did my stove top once the house lines were purged of gas everything shut down and the furnace would not light and it’s fan turned off.Just a thought.Kent
Re: Heater Thermostat Reply #18 – March 21, 2021, 06:28:04 pm Greg,I didn't like the factory Suburban thermostat because of the wild temp swings and no exact settings, only warmer and colder. I replaced it with Amazon.com: Emerson 1E78-140 Non-Programmable Heat Only Thermostat for... and I'm totally satisfied. Digital with setting temp and current temp. 4 Likes As an Amazon Associate Lazy Daze Owners' Group earns from qualifying purchases.
Re: Heater Thermostat Reply #19 – March 21, 2021, 06:41:43 pm Kent, no fan didn’t come on either. No response at all.Linda, thanks for the link!
Re: Heater Thermostat Reply #20 – March 21, 2021, 07:18:05 pm More info: Went back out and reinstalled the 10 amp fuse. The fan motor started immediately. I then put a piece of plastic in between the contacts, as Andy suggested, and the fan stopped a few minutes later. I then tried to jump start it with no effect. I think I was doing it correctly but nothing happened so I think the contacts are not dirty. I went outside and turned the propane on and turned the thermostat on all the way and the blower and heater started up as normal. Re-checked it and seemed normal again. So other than the thermostat not turning off without putting a piece of plastic between the contacts, it seems to be operating properly. Next step is to replace the thermostat and retest everything. Will give an update after the new thermostat is installed.Thanks all for your help!
Re: Heater Thermostat Reply #21 – March 21, 2021, 09:33:58 pm That digital model that Linda suggested looks good. It has what one needs, and nothing more. Setting and current temperature are both displayed, there are just two buttons and an on/off switch, and there are no bells and whistles. No clock, no menus, no programmability, no complications. Sometimes simple is best. ;-) 2 Likes
Re: Heater Thermostat Reply #22 – March 21, 2021, 10:05:49 pm I ordered a similar version from Amazon, one that Rich mentioned earlier in this thread:https://www.supplyhouse.com/Honeywell-TH1110DV1009-PRO-1000-Non-Programmable-1H-1C-Vertical-Thermostat?gclid=CjwKCAiAnvj9BRA4EiwAuUMDf7z-VwUcWrklTmuCSxj0zhuRZyin8rVp6sJyvBxO_LQ8Ow7V12vWTBoCkIIQAvD_BwEAlso, going to go to Home Depot tomorrow and see what they have. I agree, the simpler the better in this case! Hopefully it’s an easy install.
Re: Heater Thermostat Reply #23 – March 22, 2021, 08:56:05 am I've been looking at this model because aesthetically I link it would look nice in our RV while still maintaining the simplicity. Has anyone purchased this one? The only reason I am hesitant is because its supposed to switch between heat and cooling automatically. Since I would have it set up on just two wires for heat only I would think it would be ok. It also seems I would have to go through the menu system to turn it off...I don't see a physical switch. I REALLY wish I could find a nice looking black digital thermostat so it matched the right of the controls on the wall! Honeywell Home RTH5160D1003 Non-programmable Thermostat, White - - Amazon.com As an Amazon Associate Lazy Daze Owners' Group earns from qualifying purchases.
Re: Heater Thermostat Reply #24 – March 22, 2021, 09:49:00 am Another consideration is that the thermostats Linda and Rich linked to are vertical oriented, the same as the factory OEM unit.
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