Replacing an o= lder Analog RV thermostat with a new programmable digital thermostat
Control of the climate in an RV is a real challenge. T= his is often more due to the low performance thermostats that are used than becaus= e of the poor insulation and infiltration characteristics. It’s true that the newer hig= h-end RVs often have better systems but that does not help the majority of us that have budget constraints and older RVs.
My 1999 King of the Road 5th wheel RV has t= wo 40,000 BTU LP gas furnaces and 2 Air conditioners (one is also a heat pump). Under most RVing circumstances the capacity of these units is adequate but trying to stay comfortable year rou= nd is a constant struggle. Fall, winter, springtime living is a mix of being t= oo warm overnight in the bed and being too cold to shower in the morning. Going from afternoon sun warmed li= ving to quick chill down as evening temps drop outside makes for a lot of thermo= stat tweaking, too.
For us, it was important to have a comfortable tempera= ture to take a shower at 7am but sleep in a more comfortably cooler room overnig= ht. This meant that a setback thermostat would be necessary there. The typical analog thermostats just can’t be consistently set to the same exact t= emperature once they have been changed so I wanted to replace it with a digital thermo= stat that had programmable setback capabilities. I also wanted one that I could = read and/or change in the dark without having to have a flashlight.
Searching though the RVing forums I only found a few references to people that had actually made such an upgrade but the thermos= tats that they described fell short of my own goals. These few references did convince me that it was very possible to use a stick and brick thermostat o= f the proper design in my RV so I searched hardware stores and the internet and eventually found the RiteTemp line of digital programmable thermostats at H= ome Depot.
The older line, the 80xx series, seemed to offer almos= t all that I wanted but only a few models had builtin backlighting. Eventually, I found that the newer RiteTemp 60xx series are all backlit thermostats and e= asy to read under all conditions. They also have some advanced features not available in the older 80xx series that made them an even better solution f= or our needs.
But I am getting ahead of myself. I initially chose a RiteTemp 8035c thermostat for my bedroom solution because of the vertical orientation and = the horizontal space constraints I have in the mounting location. Once installe= d, it worked great and did exactly what we needed but I was not happy about st= ill having to find a flashlight to see or set it. I also found that it was nice= to be able to remove it to a more convenient place to program it but the pop-in mounting arrangement sometimes made it difficult to seat securely and more = than once, I clipped it with an arm or shoulder and it popped off the mount.
I eventually replaced the 8035c with a RiteTemp 6030 u= nit that is permanently mounted by screws and has a backlit touch screen that is much easier to see. Both thermostats worked fine and some folks may not agr= ee that the $10 price difference is worth the backlight and extra features but= it definitely is to us.
Our living room space also needed better climate contr= ol and once the bedroom solution had turned out so well, I tackled the job of replacing this thermostat with a RiteTemp 6080 Digital auto-switching thermostat with a wireless remote control. Wahoo!
What follows describes the interconnecting information= I needed to replace the 1999 vintage DuoTemp a= nalog thermostats with universally available Digital programmable thermostats. This is how I did it and while this info would generally apply to many RV installations, each situation needs to be “worked out” in advan= ce of actually cutting wires and connecting in a new thermostat.
Which would you rather be trying to see and a= djust at 2am on a too chilly morning?:
The old DuoTherm analog thermostats: = ; &n= bsp; RiteTemp model 6080 Digital programmable Thermostat w/remote
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First, A few general comments/cautions:
1.&n= bsp; Thermostats for Homes are usually designed t= o work on 24 Volts AC while RV thermostats are usually 12 volts DC or less so DON’T HOOK UP THE RV thermostat POWER WIRE TO ANYTHING ON THE NEW THERMOSTAT unless you have determined that the thermostat you are going to = use does support a 12Volt DC power supply.&nbs= p; If it doesn’t you will damage something somewhere. The RiteTemp thermostats I reference are self powered by 2 AA batteries that will run th= em reliably for over a year.
2.&n= bsp; The RiteTemp 60xx series programmable thermostats I have referenced/used have internal jumpers that must be set in addition to connecting the wiring. These jumpers are not HOT so the thermostat does not know yo= u have changed them until you press the RESET button on the thermostat. This will wipe out all your progra= mming and settings and even the Time of Day. I found that it is faster to get thr= ough all the physical setup and checks and make sure that all the hardware is wi= red correctly and the jumpers are also set correctly and that it heats and cools and blows like it all should. Once this is verified, then set your Time of = day and make your programming settings to your liking.
3.&n= bsp; RV Air Conditioners with heat pumps are a li= ttle special and take a little more thinking to get the right wiring worked out = for each case. Basically, they separate out the Heat Pump controls from the Air conditioner and work the compressor separately. In my case, this meant that= I had to hook up the LP gas furnace as a second stage aux heat and not as just AUX heat.
4.&n= bsp; To switch from cool to Heating with the heat pump requires the Freon (or generic heat transfer liquid) to be rerouted. T= his is done with a switchover solenoid that must be switched on/off depending on whether heating or cooling. It may take a test hookup with the O or B termi= nals to get it right.
Now, for those that feel lucky and won̵= 7;t RTFM anyway, click here to cut to the chase and see the technical details o= nly .
Basic Summary of what to do: (for the diligent few…)
For an RV interior space that has just an Air Conditioner and an LP gas furnace - the thermostat change is pretty simple:=
<= span style=3D'mso-bidi-font-family:Calibri;mso-bidi-theme-font:minor-latin'>1.&n= bsp; Determine the existing wiring of the thermos= tat to be replaced
<= span style=3D'mso-bidi-font-family:Calibri;mso-bidi-theme-font:minor-latin'>2.&n= bsp; Determine the equivalent connections on the = new thermostat
<= span style=3D'mso-bidi-font-family:Calibri;mso-bidi-theme-font:minor-latin'>3.&n= bsp; Make the appropriate connections.
<= span style=3D'mso-bidi-font-family:Calibri;mso-bidi-theme-font:minor-latin'>4.&n= bsp; Set any necessary soft jumpers on the new thermostat and press reset
<= span style=3D'mso-bidi-font-family:Calibri;mso-bidi-theme-font:minor-latin'>5.&n= bsp; Test that heat (furnace) works properly.
<= span style=3D'mso-bidi-font-family:Calibri;mso-bidi-theme-font:minor-latin'>6.&n= bsp; Test that the Air conditioner works properly= and that the fan in the A/C unit runs when it should and not when the furnace is running.
<= span style=3D'mso-bidi-font-family:Calibri;mso-bidi-theme-font:minor-latin'>7.&n= bsp; When the hookups are verified correct set the time of day and then program it for your desired setbacks and comfort profi= le.
<= span style=3D'mso-bidi-font-family:Calibri;mso-bidi-theme-font:minor-latin'>8.&n= bsp; Put the covers on the new thermostat and enj= oy.
O= ur bedroom heating and cooling systems work this way so you can Click here for the setup I used to install a RiteTemp 6030 in my bedroom
Basically, the process is the same but things do get a= little more complex even though there is only 1 more wire in the thermostat. Items number 2, 3 and 4 get a little more involved. This is because of the way the wires are used and what they may imply control over under different circumstances. This may not be intuitive and may change depending on what m= ode the thermostat is in.
Basically, you have individual wires for:
1.&n= bsp; Fan control
2.&n= bsp; LP gas furnace control
3.&n= bsp; A/C compressor control
4.&n= bsp; Freon flow directional control (heat pump ve= rsus cooling).
The trick is to have the thermostat match these up and activate them correctly = for the type of heating or cooling you are asking for. There is little point to having the A/C fan run when just the LP gas furnace is providing the heat.<= /p>
As I said, our main living area (kitchen, dining and l= iving room space) has this mixed type of climate control system.
You can Click here for the se= tup I used to install a RiteTemp 6080 thermostat in our main living space.
Why I chose the RiteTemp 6080 Programmable digital thermostat for my main RV living area:
The living room area includes the kitchen and dining a= reas. The roof mounted DuoTherm A/C is also a Heat Pump. This living space is also heated by a 40,000 btu Suburban LP Gas RV furnace. It is very important that the comfort and finite control of the climate in this area is well managed = and as hands-off as possible. The original DuoTherm analog RV thermostat was very inconsistent in controlling= temperatures. It was impossible to read and set without a bright light and was completely unreliable at delivering the set temperature.
Additionally, it would get the “shivers” a= nd start clicking off/on/off/on trying to run the A/C, heat pump or even the f= urnace at marginal times. This is very hard on the equipment and can drastically shorten its life. I also did = not like the fact that I had to watch the outside and inside temperatures to be sure that when it was too cold for the heat pump to kick on, that it did not get too chilly inside before I manually switched over to the furnace for he= at or could switch back to the heat pump for LP gas conservation.
The things I wanted to accomplish in replacing my living room thermostat were:
1.&n= bsp; Comf= ort – Maintain a crisp control over the temperature and humidity in the RV.
2.&n= bsp; Visi= bility – See it easily without glasses and in the dark
3.&n= bsp; Conv= enience – “Set-it and forget-i= t” was really desirable. I Wanted auto switchover from heat pump to LP gas and also auto-switching from Heating to cooling mode.
4.&n= bsp; Econ= omy – Better control over temperature variances without fiddling with the thermostat.
The way the 6080 addresses my goals:
1.&n= bsp; Visi= bility - The RiteTemp 6080 thermostat appeared to have all the features and capabi= lities at a reasonable price. The digital readout is very large with good contrast= and automatic backlighting whenever any key or touch area is activated.
2.&n= bsp; Comf= ort - The amount of temperature drop or rise before triggering heating or cooling= can be altered to allow more sloppiness or a tighter limit of variance. However= , if the range is set too tight, it will be switching off and on much more frequently than is efficient.
3.&n= bsp; Conv= enience – The 6080 will switch automatically from heating to cooling based on= the temperature it is seeing. Automatic switching from using the heat pump to u= sing the LP gas furnace when necessary is very nice and saves having those ̶= 0;I am chilly” episodes where you realize it is too cold outside (usually below 40 degrees) for the heat pump to kick on anymore. It can also monitor the rate of temperature improvement and if it is not warming up fast enough then it will automatically turn on the LP gas furnace to bring the temperature up a little faster.
4.&n=
bsp;
Econ=
omy
– The switching on/off of the LP gas furnace can be adjusted to be mo=
re
economical or more aggressive to give quicker temperature rise in the RV.
For convenience and more specific control there is a H= EAT PUMP OFF switch that will cut the heat pump completely off leaving heating = up to just the LP Gas. This give= s an operation similar to the original thermostat that only gave you a choice of heating with the heat pump or with gas but not with both.
This thermostat also can be calibrated to your own thermometer by a +- 6 degree difference so it can be made to read what your wall thermometer does (allowing for differences in location and exposure).<= /p>
It displays Relative humidity and can control a humidi= fier or dehumidify (using the A/C) if you choose to have one or need dehumidification.
I like the random fan mode, too. It kicks on the a/c f= an for 5 minutes about every hour, just to circulate the air a bit. It’s not= a biggie but it does help soften pockets of humidity or stale air that tend to accumulate in certain areas.
The one feature that I have not tried just yet is the “hot flash button”. This thermostat does come with an RF remote control that will work at up to 50 ft through walls, etc. As many will atte= st, the logic of “you’re not really hot” is lost on someone suffering a hot flash and trying to be comfortable when hot flashes strike involves a lot of dicking with the thermostats. The remote control that comes with= the 6080 does require 24volt AC power supply to the thermostat to operate the receiver portion. Adding a 24volt ac supply would have to be worked out and wired into it to have the remote work.
One advantage of doing this, however, is that it then = will also power the thermostat when your shore power is connected allowing the batteries to last a great deal longer.
There may be other thermostats out there that can do a= ll of this satisfactorily but in my limited research I could not find one that met all of my criteria within my budget. At $99 at Home Depot, the 6080 RiteTemp Digital programmable thermostat met all requirements and then some. Their t= ech support and engineering folks helped me resolve questions about the way the= ir thermostats work and what configuration changes I needed to make in RV use. There was never any mention by anyone that use in an RV was not a supported installation.
<=
span
style=3D'font-size:14.0pt;line-height:115%'>Short=
cut
instructions for the “cut-to-the-chase folks that feel lucky”
1.&n= bsp; Don’t hook up the power wire from the = A/C.
2.&n= bsp; Wire the 2 fan speed wires together to the G terminal
3.&n= bsp; Use the appropriate cross-wiring matrix table for your chosen thermostat.
a.&n= bsp; RiteTemp= 6030 Digital thermostat wiring
b.&n= bsp; Rit= eTemp 6080 Digital thermostat wiring
Notes
for using RiteTemp 60xx series thermostats:
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· &nbs=
p;
Reset must be
pushed after jumper changes or the changes will be ignored. |
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· &nbs=
p;
Reset wipes out=
ALL previous settings<=
/span> including time of day=
. |
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· &nbs=
p;
No Hi/Lo fan capabili=
ty
so put both fan wires together under the G terminal for Hi fan speed only=
. |
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· &nbs=
p;
Tie off and insulate =
the
+12volt wire from the A/C. it cannot be used. · &nbs=
p;
Touch Screens have
software protection from "clumsy fingers" so be sure to press a
single point and don't let the stylus/finger slide at all. If it does not
respond, wait 10 seconds and then use a stylus to press firmly in just one
specific touch enabled area. |
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· &nbs= p; The standoffs may be needed in some mounting locations to allow better air circulation around = the 60xx thermostats to give more immediate sensing and temperature control.<= o:p> · &nbs=
p;
The screw terminals do
not require stripped wires but be careful because the screw heads can be
twisted off if too much torque is used. |
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Wiring conversion tables for moving wiring fr= om DuoTemp analog thermostats to RiteTemp Digital Thermostats:
The old analog DuoTherm thermostat connections layout
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Figure 1 Duotherm Analog thermostat connections
· HS/HP wire is not present for non-heat pump equipped Air Conditioners
· The +12 wire will not be used so tape it off= .
· See the appropriate matrix below for the equivalent wire markings for the standard RiteTemp thermostat terminals.
RiteTemp Model 6030 Digital Programmab=
le
Thermostat Connections and Jumpers.
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= RiteTemp 6080 Programmable Digital Thermostat Connections and Jumpers
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<=
span
style=3D'mso-no-proof:yes'> Figure
3 RiteTemp 6030 Jumpers
Reference |
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