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Topic: Digital Thermostat question

Posted By: oakmandan on 02/11/09 08:47pm

I realize digital thermostats have been spoken of on these forums before, but I have a couple simple questions...

I want to replace my old thermostat that is only used for the furnace due to having no A/C unit.
1) Do they make a digital thermostat for just furnaces?
2) Is there a special unit I will need due to being a 12V system?
3) What brands and models have you used in a mod like this?

Thanks, Dan


Dan and Diann
Hank the Havanese
2019 Grand Design Reflection 320MKS
2015 Ford F-250 FX-4 6.2 Gas
MORryde Step Above Steps
MORryde Pin Box



Posted By: mike4947 on 02/11/09 09:13pm

moved from folding trailer forum


Posted By: jbbrick on 02/11/09 09:19pm

I've got your answer, I did it today with my own MH. There is a thread elsewhere regarding problems with a Carrier AC unit that has controls combined with the furnace control. Today I disconnected their system and installed a new digital stat to control just the furnace. Bottom line, super simple for you. Just take the two wires and connect them to a new digital stat and you're done. Some factors:

You must have a battery powered stat, most of them are-with AAA or AA batts. Read the package, it should say "requires two __ batteries".

Voltage is no problem, they only switch the circuit, and are not powered by it.

My stat today is a Honeywell Model RTH221B that I got from Home Depot for $25. I picked this one because its cheap, small, vertical style, and is programmable for 7 days with the same program. Campers don't want a different schedule for weekends. It also can be put on hold pattern to keep your rv from freezing if that's an issue. If you get this stat, your two wires will connect to the "rh" and "w" terminals.

Good luck, don't worry, just do it. Jerry


'06 Itasca Suncruiser 33'
2016 Ford Edge toad


Posted By: Hoppers4 on 02/11/09 09:24pm

1) Yes
2) System voltage irrelevant
3) Replaced mechanical furnace thermostat with digital Honeywell RTH110B.

Brick has it right. Small, cheap, no clock no need for auto setback.


2015 Jayco Greyhawk 29MV


Posted By: fairfaxjim on 02/11/09 09:26pm

1 - Yes, you can get heat only digital thermostats, both programmable and non. You can use a heat/cool one too, you just don't connect anything to the cool terminals and leave the switch set to heat.

2 - Any digital thermostat that has a battery in it will work. The battery provides the power for the thermostat, and the connection to your PUP heater is just 2 wires to a normally open contact in the thermostat. Hook the wires from the heater to the thermostat to terminals R and RH, ignore the rest.

3 - Just about any brand that has a battery in it will work. I, and many other use the LUX brand - they are pretty readily available in a number of different styles. Hunter, Honeywell, White/Rodgers, should all work.

I installed mine using a 1/4" phono plug and jack (like the fan/light accessory uses to connect to the ceiling light) so I can hang it where I want - usually closer to the bed at night, and to get it up higher than the knee high cabinet mounting of the stock thermostat. I also wired it in parallel with the stock mechanical one, so that should the battery go dead or the thermostat go paws up, I could just revert to the original until the problem is solved (and not have to solve it in the middle of the night.)


Jim & JoAnne
2016 Toyota Tundra SR5 TRD Double Cab
2004 Starcraft 11RT (Replaced by)
2011 Eclipse Milan 18CK Travel Trailer



Posted By: hwybnb on 02/11/09 09:41pm

Most people on this forum seem to use the Hunter digital thermostat, probably because it is cheap and available at Walmart. The information on this link explains how to do it. In your case just ignore the parts having to do with the air conditioner.


Posted By: Bumpyroad on 02/12/09 04:28am

as primitive as RV HVAC systems are, why spend the money on a digital one?
bumpy






Posted By: Coachman Dave on 02/12/09 06:35am

Come on Bumpy....you know people will go to great lengths to modify their rigs. Why do guys put Blaupunkt stereos in their 1984 Ford Escorts? Anything to spruce up a car or a rig. If you look at Oakmandan's rig, while it may not be a diesel pusher, it looks almost new, well taken care of, and like it deserves a few of the modern amenities.


2011 Coachmen Freedom Express 295 RLDS


Posted By: accsys on 02/12/09 06:51am

Bumpyroad wrote:

as primitive as RV HVAC systems are, why spend the money on a digital one?
bumpy

So the temp range isn't 72 ± 5 degrees, but 72 ± 1 degree! With factory thermostats, you're freezing before the heater kicks on and burning up before it kicks off. A quick and easy $25 mod makes it much more pleasant.


John & Doris
Doris and Robbies Blogs
2007 Tiffin Phaeton QDH 40 w/Cat 7 350 (Mothership)
2004 Liberty Renegade 4x4 Toad (Libby)
Roadmaster Falcon 2 tow bar
Air Force One toad braking system
FMCA F380583, PA, Good Sams




Posted By: red31 on 02/12/09 07:38am

accsys wrote:

Bumpyroad wrote:

as primitive as RV HVAC systems are, why spend the money on a digital one?
bumpy

So the temp range isn't 72 ± 5 degrees, but 72 ± 1 degree! With factory thermostats, you're freezing before the heater kicks on and burning up before it kicks off. A quick and easy $25 mod makes it much more pleasant.


A fan would work better or moving the thermostat from 6" off the floor to 5' off the floor - difficult in a PU! A divertor helps.
Adjust the anticipator.


Posted By: Bumpyroad on 02/12/09 09:01am

red31 wrote:

accsys wrote:

Bumpyroad wrote:

as primitive as RV HVAC systems are, why spend the money on a digital one?
bumpy

So the temp range isn't 72 ± 5 degrees, but 72 ± 1 degree! With factory thermostats, you're freezing before the heater kicks on and burning up before it kicks off. A quick and easy $25 mod makes it much more pleasant.


A fan would work better or moving the thermostat from 6" off the floor to 5' off the floor - difficult in a PU! A divertor helps.
Adjust the anticipator.


yep I think just putting the fan onto continuous circulation throughout the RV would go a long ways towards enhancing comfort.
and I dare say in something as primitive as an RV, sitting next to a wall or window would have a much larger effect on discomfort than trying to regulate temperature -+ 1/2 degree.

bumpy


Posted By: LAdams on 02/12/09 09:13am

Actually, it has been my experience, at least for us, that having the fan on all the time is a bit more "uncomfortable" in the form of being drafty, and with the A/C, especially on a hot humid day, the TT stays more humid because of the air drawn into the TT...

For heat only, simply hook the 2 thermostat wires to the "RC" and "W" terminals of the Hunter, Lux, etc... You can click on the link in my signature for the ORIGINAL article on the Hunter install from Spring 2001...

Les


2000 Ford F-250SD, XLT, 4X4 Off Road, SuperCab
w/ 6.8L (415 C.I.) V-10/3:73LS/4R100
Banks Power Pack w/Trans Command & OttoMind
Sold Trailer - not RV'ing at this point in time



HUNTER THERMOSTAT INSTALL

HOME MADE WHEEL CHOCKS


Posted By: oakmandan on 02/12/09 09:35am

Hey all, thanks for all the advise. I just can't wait to get the rig out and "play" with it! I do find with the old thermostat I have, it gets cold, then hot, then cold..... I have been told a digital mod would help with that problem.

Dan

* This post was edited 02/12/09 09:46am by oakmandan *


Posted By: Bumpyroad on 02/12/09 09:45am

LAdams wrote:

Actually, it has been my experience, at least for us, that having the fan on all the time is a bit more "uncomfortable" in the form of being drafty, and with the A/C, especially on a hot humid day, the TT stays more humid because of the air drawn into the TT...

snip


my furnace fan does not draw outside air into my RV. that seems like being sort of counterproductive, draw 0 degree air into a RV you are trying to heat?
but trying to precisely control the imprecise seems like a losing battle to me. with a RV having so few heat sinks as compared to a house, you will always get some fluctuation.
bumpy


Posted By: jbbrick on 02/12/09 09:52am

When I posted earlier re installing a programmable stat I forgot that some folks don't need that feature and only want a more accurate plain-old digital stat. For my money, $25 is cheap and you can have a clock and also have the heat come on 1/2 hr before you get up. I've left all the other cycles on 62 and use just the am "wake" cycle.

You guys also mentioned adjusting the anticipator..from my experience, all anticipators work on 24v and are designed for home use where your furnace has a 24v transformer. I doubt that it would do much on 12v but our rv's are so small that I doubt if the temp swing is more than 2 deg overshoot even without the anticipator. It appears that the Atwood is set up for 12v anticipator but I think its still a piece of junk. Just my 2 cents. Also, the Hunter stat seems a bit large, though I haven't seen it in person. I like the Honeywell size and configuration for the price. Jerry

* This post was edited 02/12/09 11:44am by jbbrick *


Posted By: red31 on 02/12/09 09:54am

oakmandan wrote:

Hey all, thanks for all the advise. I just can't wait to get the rig out and "play" with it! I do find with the old thermostat I have, it gets cold, then hot, then cold..... I have been told a digital mod would help with that problem.

Dan


It will if you never adjusted the heat anticipator.

Think about the weather down near the floor where your pop up thermostat is located!

I don't think you have the option to leave the fan on

Programming a digital thermostat 6" off the floor is hard on the knees and requires reading glasses! The anticipator works and atwood suggests it come set at 1 and to lower it to about .5 (the installer failed to do this in all cases).atwood mechcanical thermostat/anticipator adjustment.


Posted By: Coachman Dave on 02/12/09 10:24am

Oakmandan,

Good luck with the mod. Your trailer and truck look perfect!! What year is the trailer?

Coachman Dave


Posted By: ScottG on 02/12/09 10:31am

Deleted


Scott, Grace and Wesly
2003 Dodge 3500 4x4, 6 speed Cummins.
2018 Silver Fox 32A.
H0NDA eu2000i


Posted By: Coachman Dave on 02/13/09 09:46am

Oakman,

Cats stay home with the wife. She loves them....me, not so much.

Coachman Dave


Posted By: beemerphile1 on 02/13/09 10:44am

To those that have replaced their mechanical thermostats with digital, did you ever adjust the heat anticipator first? Be honest now.

I was not happy with the cycling of my cheapo mechanical thermostat until I adjusted the anticipator. Now it works just as good as the $150 thermostat in my sticks and bricks. I don't have any need to replace it and that is less batteries to remember replacing.


Build a life you don't need a vacation from.

2016 Silverado 3500HD DRW D/A 4x4
2018 Keystone Cougar 26RBS



Posted By: AO_hitech on 02/13/09 11:04am

fairfaxjim wrote:

I also wired it in parallel with the stock mechanical one...


Thanks for that idea. I assume you could use that to keep the furnace on if either one is cold enough to turn the furnace on, right?

Thanks for the idea.





Posted By: oakmandan on 02/12/09 11:25am

Thanks Coachman, The PUP is a 1994 model, bought new in 1995 by my parents.


Posted By: Harry Havasu on 02/12/09 12:03pm

It'll be the best $20.00 you ever spent. If you don't like it - just return it.

If our friend and frequent poster "Bumpy" prefers to keep his analog device, we can just respect his decision without agreeing to it.

And, of course I don't

Good luck - there's nothing to the change out for heat only,

Tom


Harry Havasu


Posted By: Dusty R on 02/12/09 01:13pm

2 - Any digital thermostat that has a battery in it will work. The battery provides the power for the thermostat, and the connection to your PUP heater is just 2 wires to a normally open contact in the thermostat. Hook the wires from the heater to the thermostat to terminals R and RH, ignore the rest.

Not quite true. Some thermostates have batteries for back up but operate on 24 volt AC.
For an RV you need one that operates on battery but will have dry contacts, just a switch.

Dusty


Posted By: LAdams on 02/12/09 02:16pm

Bumpy, I was talking about the A/C in particular, and especially on a humid day... Your furnace draws in outside air through it's exhaust which is really a tube within a tube... Out side tube is for fresh air for conbustion and inside tube is for exhaust...

Les


Posted By: LarryJM on 02/12/09 03:15pm

Bumpyroad wrote:

snip ... trying to precisely control the imprecise seems like a losing battle to me. with a RV having so few heat sinks as compared to a house, you will always get some fluctuation.
bumpy


I agree and especially trying to heat a tent sided PU [emoticon] Trying to control the temp too close is just going to cycle the furnace more reducing it's overall life before needing either repair or replacement.

I guess it's a popular mod, but one that I can't see much to be gained from doing it and can think of several things that would say not to do it.

Larry


2001 standard box 7.3L E-350 PSD Van with 4.10 rear and 2007 Holiday Rambler Aluma-Lite 8306S Been RV'ing since 1974.
RAINKAP INSTALL////ETERNABOND INSTALL



Posted By: 4runnerguy on 02/12/09 03:31pm

Bumpyroad wrote:

as primitive as RV HVAC systems are, why spend the money on a digital one?
bumpy
I haven't done the conversion yet, but the main thing that attracts me to it is that on some digital thermometers the temperature can be set to around 40 degrees. The minimum on my mechanical one is somewhere around 50 degrees, which is just too warm for our usage. (We sleep under a big down comforter.)

fairfaxjim wrote:

I installed mine using a 1/4" phono plug and jack (like the fan/light accessory uses to connect to the ceiling light) so I can hang it where I want - usually closer to the bed at night, and to get it up higher than the knee high cabinet mounting of the stock thermostat.
What a great idea! We want to control the temperture where we are sleeping, not on the floor where our feet aren't during the night! I'm glad I waited to change the old thermostat out until I read your idea!


Ken & Allison
2 Camping Cats (1 diabetic)
1996 4Runner, TRD Supercharger, Edelbrock headers
2007 Fleetwood Arcadia, Honda EU2000i
4 mountain bikes, 1 canoe, 4 tents, 8 sleeping bags, 2 backpacks
(You get the idea!)



Posted By: Bumpyroad on 02/12/09 03:55pm

4runnerguy wrote:

Bumpyroad wrote:

as primitive as RV HVAC systems are, why spend the money on a digital one?
bumpy
I haven't done the conversion yet, but the main thing that attracts me to it is that on some digital thermometers the temperature can be set to around 40 degrees. The minimum on my mechanical one is somewhere around 50 degrees, which is just too warm for our usage. (We sleep under a big down comforter.)

fairfaxjim wrote:

I installed mine using a 1/4" phono plug and jack (like the fan/light accessory uses to connect to the ceiling light) so I can hang it where I want - usually closer to the bed at night, and to get it up higher than the knee high cabinet mounting of the stock thermostat.
What a great idea! We want to control the temperture where we are sleeping, not on the floor where our feet aren't during the night! I'm glad I waited to change the old thermostat out until I read your idea!


yes, I can see where a better thermostat might be beneficial, eg the 40 degrees, also a timer to kick it on 30 minutes before getting up, but only if it could be on all night at a lower temperature.
I dare say that if one would do a heat distribution study throughout their RV they would find up to 10 degree differences throughout.
bumpy


Posted By: StreetRodderTom on 02/12/09 09:24pm

I would guess that one main reason some of us would use it is for the setback feature. Have it to a lower temp setting at night but have it come up to that nice warm setting 1 hour before you "have to" roll out from under that nice electric blankie!


Hope to see you on the road!!!
Retired Gunsmith (35+ years)
Wife is retired RN (VA Hospital 37 years)
2005 Starcraft Model 2409



Posted By: Coachman Dave on 02/13/09 06:58am

Oakmandan,

Thanks for the info. Since you introduced me to this site, I have spent a lot of time looking at pics of great campers and getting great tips. I asked you about the year of your trailer....I guess if I pull my head out, I would have seen that the year was right there in your signature. Last I knew, you had a piece of s**t old Coleman. How did you talk your parents out of their pristine camper? How are they doing?

Great to re-connect...

Dave

PS....sorry to hear of the death of your cat Misty, I know you had her for nearly 20 years. Did she camp with the Bassetts from Hell?? [emoticon]


Posted By: oakmandan on 02/13/09 09:41am

Coachman,

It took me two years of hard work on my parents to get them to give up that PUP!. I do miss the my old Coleman, if you remember, it was still a finer rig than your 92 Dodge Minivan you use to camp in! We sure had fun camping back in the day. Do you still take all 3 of your cats camping with you?

Dan


Posted By: blkfe on 02/14/09 02:03pm

beemerphile1 wrote:

To those that have replaced their mechanical thermostats with digital, did you ever adjust the heat anticipator first? Be honest now.

I was not happy with the cycling of my cheapo mechanical thermostat until I adjusted the anticipator. Now it works just as good as the $150 thermostat in my sticks and bricks. I don't have any need to replace it and that is less batteries to remember replacing.


I had adjusted my anticipator numerous times. Maybe my thermostst was just plain broken....I don't know.....but,
Installing the $25.00 Hunter from Wallyworld was the best mod I have ever done on my RV...and I have done a few!!!
Brad


Posted By: fairfaxjim on 02/15/09 09:52pm

AO_hitech wrote:

fairfaxjim wrote:

I also wired it in parallel with the stock mechanical one...


Thanks for that idea. I assume you could use that to keep the furnace on if either one is cold enough to turn the furnace on, right?

Thanks for the idea.


Yes, the one with the warm setting will prevail. I keep the mechanical one turned off and let the digital one do the work. If it goes dead, turn on the mechancial one.


Posted By: doughere on 02/16/09 01:53pm

The anticipator depends on current flowing through the T'stat. Most electronically controlled units don't draw enough current for the anticiparot to do any good. An inexpensive digital will do a good job for a small price. When selecting a T'stat look for a model that is battery powered, and designed to use with a milivolt system. As stated above, some use the battery for program backup, not to actually switch, some for 24VAC only will have a triac (won't switch DC) instead of contacts; a T'stat designed for milivolt operation will have contacts.
I've replaced the mechanical T'stats in a PU and a 5er, in both instances the digital stat made the units MUCH more comfortable.

Regards,
Doug


Posted By: AO_hitech on 02/16/09 01:59pm

fairfaxjim wrote:

Yes, the one with the warm setting will prevail. I keep the mechanical one turned off and let the digital one do the work. If it goes dead, turn on the mechanical one.


Thanks, that is what I thought. The mechanical one currently is in the "bed room" that is closed off at night. The main living area where the kids are can get cold. I plan to install a digital one in the main area and leave the mechanical one. I can set it a little cooler and if the "bed room" gets to cold the furnace will come on. This gives me MANY more heating options.

Thanks for the great idea. This needs to be in the gizmos and gadgets thread! [emoticon]


Posted By: javaseuf on 02/16/09 08:47pm

Digital (electronic) stats don't have a current sensing anticipator. It is electronic and works by programing the number of degrees you want the temperature to change between on and off.






Posted By: roamerr on 02/26/09 05:16am

Just installed a digital Thermostst. Nice! I found a Ritetemp thermostst on clearance at Home Depot for under $10 -- normally $49.

[image]

[image]


2009 Cherokee Wolfpack DFWP27 Toyhauler
2008 Dodge Ram 1500 Hemi Quad Cab w/3.92
Can-Am Outlander 800R Ltd
Club Car DS Lifted and Modified for campground fun
2 dogs - Basset Hound and German Beagle (mutt)
Great Family Fun!!



Posted By: beemerphile1 on 02/26/09 06:04am

Okay I jumped on the bandwagon myself even though I was happy with my mechanical stat.

I had a slightly used digital stat on the shelf in the shop (I do building and construction) that I had removed from a house and installed a programmable one. So I took that free digital stat and installed it in the original location of the mechanical.

I then ran some stat wire and installed the mechanical stat beside the bed. I got the idea from fairfaxjim's post. The DW is very pleased that now she can bump up the heat before getting out from under the covers in the morning. It works well for me when the DW is happy. [emoticon]

Thanks fairfaxjim for the idea.


Posted By: rvfamilyguy on 02/27/09 02:42pm

roamerr wrote:

Just installed a digital Thermostst. Nice! I found a Ritetemp thermostst on clearance at Home Depot for under $10 -- normally $49.

[image]

[image]


Hey Roamerr I picked up one of those RiteTemp $9.95 units at Home Depot myself and really would be interested in any help I could get with wiring the thing. I have a factory Duo Therm thermostat in my Rockwood 2306 and think this would be a great mod to try. I actually bought an stsp sub mini switch and installed it in the new RiteTemp unit. I noticed you added the toggle switch for the low/hi fan operation, does it work and how did you wire it?

* This post was edited 02/27/09 05:00pm by rvfamilyguy *


1 DD"> and DW
2006 Rockwood 2306
1999 GMC Yukon
Equalizer Hitch

It's said that life is short, but eternity lasts forever, better get it right.


Posted By: LAdams on 02/27/09 03:57pm

The problem with a lot of the OEM thermostats like my DuoTherm is that they do not have any anticipator adjustment... The swing from off to on with my old Dometic (Duo Therm) was in the 5-6 degree area so even setting it at say 70 meant that the temp in the TT would drop to 65 before it ever came on... And if you set it up higher, the overshoot before it would turn off would have you sweltering...

You can say what you want about sophisticated technology in a non-sophisticated environment but I'm here to tell you it will be THE BEST $20-$25 bucks you have ever spent - period!!! I've had my original Hunter in 3 different trailers now... It's the first thing I move and the last thing I take out when I buy a new TT... I for one would NOT be without a digital stat [emoticon]

Les


Posted By: 96Bounder30E on 02/27/09 04:01pm

LAdams wrote:

You can say what you want about sophisticated technology in a non-sophisticated environment but I'm here to tell you it will be THE BEST $20-$25 bucks you have ever spent - period!!!
Les


I couldn't agree with you more!


In my Bounder, I want to put a thermostat in with a remote control........so, while I'm rolling down the road I can turn the A/C on and off without getting up from the drivers seat.......


Eric
96 Bounder 30E-F53(460)
stock Ford intake w/K&N air filter
used Thorley headers
new Banks resonator, muffler, tail pipe and 4" polished SS exhaust tip




Posted By: LAdams on 02/27/09 06:16pm

Yeah!!! That's what I'm talkin' about!!! [emoticon] [emoticon] [emoticon]

Les


Posted By: dwayneearle on 05/03/09 11:47am

Thanks guys... exactly what I wanted

Dwayne


2006 Chevrolet Trailblazer EXT
2005 R Vision TC26QHB


Posted By: Tizi on 05/01/09 02:25pm

I put in a Honeywell. Simple, took about 10 minutes. Nice bang for the buck upgrade. Install wires and batteries and off you go.

[image]


2008 Dodge Ram 2500 QC 4x4 - HEMI
2007 Northern Lite 10.2 RR
Tizi's Transformer by Whazoo



Posted By: Hurricaner on 05/01/09 04:51am

dwayneearle wrote:

Does anyone know of a model that has a remote??

Dwayne
Here you go. https://www.acehardwareoutlet.com/(t1gsv........dmu55)/productDetails.aspx?SKU=905460010

remote manual
http://www.luxproducts.com/ART/support/T........000RF_Web_RF-Addend_TriLang_20051027.pdf

* This post was edited 05/01/09 05:03am by Hurricaner *


Sam & Kari
Hurricane, Utah


2019 Winnebago Sightseer 33C


Posted By: AO_hitech on 04/30/09 04:39pm

accsys wrote:


So the temp range isn't 72 ± 5 degrees, but 72 ± 1 degree! With factory thermostats, you're freezing before the heater kicks on and burning up before it kicks off. A quick and easy $25 mod makes it much more pleasant.


I installed a digital one and wow!, what a difference. I also changed the location, but the difference was like installing a whole new heating system. I'm very glad I read this thread BEFORE we went snow camping. [emoticon]


Posted By: dwayneearle on 05/01/09 03:24am

Does anyone know of a model that has a remote??

Dwayne


Posted By: 96Bounder30E on 02/27/09 06:35pm

Les,

My wife totally freaks out when I get up to go use the restroom or get a drink while we're rolling down the highway..........I guess she just doesn't understand how cruise control works[emoticon]


Posted By: LAdams on 02/27/09 06:45pm

[image][image][image][image][image][image]

That's Great Eric!!!


Posted By: Harry Havasu on 02/28/09 02:05pm

Why are you several of you guys continually opposed to someone who wants to spend $20.00 and go digital ???

He isn't telling you to upgrade - so I suggest you respect his wishes.

Hwybnb offered a constructive website that tells him everything he needs to know - and more, so this can be a learning experience for him as well as a fun experience.

For me - having a stock RV or truck or automobile with no creative upgrades is sterile and has no personality and is no fun to drive. But if you choose to leave your toys stock, it's your decision and I repsect it.


Posted By: AO_hitech on 03/01/09 03:59pm

I just installed mine. Much nicer! [emoticon]


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