AC Thermostat question

zernalaw · 03-17-2015, 07:11 AM

Just purchased a 2007 Jayco Eagle.

The original 2007 Ac works OK but thermostat does not. (In that the AC blows cold and does not shut off at desired temperature.) Will it be possible to:

1. Install a new wall thermostat?

2. If so- can I upgrade to a digital thermostat?

I will upload model number later...

I'm a truck camper girl, so this TT is all new territory.

BTW- I bought a Jayco in part, because every Jayco owner I've ever met had nothing but good things to say about their rigs!

-Zerna

Brownie · 03-17-2015, 07:50 AM

Zerna,

Congratulations on your "new-2-u" Eagle, and welcome to The Forum!

I'm certainly no expert on thermostats, but I did replace the one in my "stick-n-bricks". It was pretty simple. Typical trailer thermostats aren't terribly accurate - for either heating or cooling. They tend to allow for wide swings in temps before turning on/off. Several Forum members have replaced their thermostats with digital ones. Some have gone without a hitch, others . . . not so much. Those that have had the most success have used the digital thermostat made by their A.C. manufacturer. The wiring seems to be a little easier going that way. You may want to do a subject search, here, on "thermostat replacement" to gain a little more insight. I'm sure others with hands-on experience will chime in soon with more recommendations.

Hope you enjoy your new trailer. Please keep us posted (with pictures) about your adventures with mods and with camping.

The Logans · 03-17-2015, 08:19 AM

We put a digital in... and then removed it again and went back to a standard thermostat. That was because it was a parasitic drain on the batteries when in storage. When the camper batteries went dead, then the thermostat was running on it's internal battery till that went dead. Then the thing had to be re-programmed... the original thermostat is completely maintenance free. No batteries, no programming.

**Mustang65** · 03-17-2015, 09:38 AM

Looking at my basic (standard) thermostat and the wiring diagram, the only issue that I see would be the selection of the FAN speed. Normal digital thermostats do not have this option. But that is not to say that you could not mount a small external DPDT toggle switch on the side of the new digital thermostat (Low/High speed) to handle that lacking function.

I am sure that someone here has already made a modification of this type already.

You could also add an main toggle switch to turn on/off the use of the thermostat for storage.

Just my thoughts,
Don

Wrascal · 03-17-2015, 11:45 AM

Coincidentally just last evening I purchased a used digital RV (2 speed fan) thermostat, for $25 (+ $8 S&H). This morning when I reviewed this purchase I find the ebay seller has posted another one - with the same option to "make an offer". I suggest giving him a try.

My original purchase here: RV Coleman Mach Thermostat RV Comfort HC Black | eBay

Notice along the top it says "The seller has relisted this item or one like this." Click on it and see if he'll accept your bid.

EDIT: I now find that you can go directly there by clicking the above blue "relisted this item". Then if interested, make an offer.

The first 2 white pics are my original (inaccurate) stat; the 2 black pics are what I've purchased. The original stat uses 6 wires soldered onto the board; I will snip them off then connect to the new stat wires using electrical nuts, matching color for color. I will post results next week once received.

troutslayer · 03-17-2015, 12:34 PM

I replaced the standard Coleman-Mach thermostat with another brand digital one bought at one of the Big Box stores and had problems trying to match up the wiring so it never worked exactly right. I trashed that one and bought the digital Coleman-Mach thermostat (just like Wrascal has, only white in color) and the wires matched up perfectly. it does not operate on separate (AAA or AA) batteries so it does draw a small amount of power from the house battery but not so much that I have noticed. All in all, I'm pretty happy with the new thermostat.

Cosmik Debris · 03-17-2015, 02:14 PM

I replaced our oem with a digital and it works great. Look (or search ) the mods section for help.
On our last rv I did install the switch that Mustang65 describes, and the hardest part of that was finding a toggle we liked that wasn't just on/off. Got one on amazon.
The downside of power draw is real, but the upside of not having AA batteries is a plus.

RedHorse1 · 03-17-2015, 02:43 PM

we've got 2 similar to what wrascal has installed. No battery in ours. One is AC only and the other is AC-Furnace. There are several things in your TT that will be potential parasitic battery drains (stereo, CO/Propane detector, Micro). Install a battery disconnect switch or pull the battery fuse to be sure.

**WVDusty** · 03-17-2015, 06:41 PM

Hey Wrascal thanks for the link. I ordered one today.

SmokerBill · 03-17-2015, 06:44 PM

You know, I've had thermostats with batteries in the for years, and a set seems to last for over a year. Making them a part of your annual/bi-annual smoked detector battery replacement routine, you never have any thermostat problems.

Just don't want battery powered thermostats to be totally ruled out of the possibilities.

With Irish Cheeeer,

Wrascal · 03-17-2015, 06:45 PM

Did you opt for this used one or another/new one? Price?

I thought $25 (with a return policy) was a good deal, much better than the normal $60-$80, up to $180.

mdany · 03-17-2015, 07:43 PM

Quote:

Originally Posted by Wrascal

Coincidentally just last evening I purchased a used digital RV (2 speed fan) thermostat, for $25 (+ $8 S&H). This morning when I reviewed this purchase I find the ebay seller has posted another one - with the same option to "make an offer". I suggest giving him a try.

My original purchase here: RV Coleman Mach Thermostat RV Comfort HC Black | eBay

Notice along the top it says "The seller has relisted this item or one like this." Click on it and see if he'll accept your bid.

EDIT: I now find that you can go directly there by clicking the above blue "relisted this item". Then if interested, make an offer.

The first 2 white pics are my original (inaccurate) stat; the 2 black pics are what I've purchased. The original stat uses 6 wires soldered onto the board; I will snip them off then connect to the new stat wires using electrical nuts, matching color for color. I will post results next week once received.

wrascal,
I have made the switch from the original T-stat to the Digital Coleman model, like you have pictured, and we have not been happier!. The digital unit is much more accurate, it cycles the AC/Heat when the temp is +/- 3 degrees from the setpoint. The original style would allow for approx a 10-degree differential from the setpoint. Enjoy your new temperature controller.....you will no longer need to throw your blankets off when it gets too hot, and then pull them back up (20-minutes later) when it gets too cold -sound familiar??

Wrascal · 03-18-2015, 07:47 AM

We don't generally spend much time inside so it wasn't previously noted, UNTIL this past week when we were stuck inside (rain) 4 days with two youngsters and two dogs. What I discovered was when warm (or cold) I couldn't just bump the temp setting, it needed a major movement to kick things in. That of course led to frequent trips to correct the prior adjustment.

**WVDusty** · 03-18-2015, 03:21 PM

Quote:

Originally Posted by Wrascal

Did you opt for this used one or another/new one? Price?

I thought $25 (with a return policy) was a good deal, much better than the normal $60-$80, up to $180.

Used. To good of a price to pass up!!

Wrascal · 03-19-2015, 10:33 AM

Earlier this morning I received the thermostat, dusty. When I opened the two part plastic shell I noticed it's missing the fuse; what makes that bad is it's not labeled as to what the fuse specs are (volts/amps).

Anyone here care to peek at a similar stat fuse and advise? Thank you.

**norty1** · 03-19-2015, 11:21 AM

2a 250v

**WVDusty** · 03-19-2015, 01:37 PM

Good to no. Thanks wrascal and norty!!!

Wrascal · 03-19-2015, 03:42 PM

I just realized the word play there; when I said dusty I was describing its appearance, not addressing Dusty.

I checked my original stat and it had a 2A/250V fuse in it, however it was one of the physically smaller ones - and I needed one of the older larger glass tube ones. I rummaged thru my junk pile and found a 2A/32V of the correct physical size.

Popped this alternate fuse in and wired things up; it all appears to be working now but do want to get the correct fuse. I observed a two degree swing (from room temp) to get things activated (both heat and air) and checked that the dual fan speeds work as they should. And just to harass some folks, the room/outdoor temp was a cool 75*.

Additional info, when I pulled the old stat unit and stated pulling the 6 wires from the wall I had lots of slack - then I found inside the wall they were already tied with electrical nuts. The only non-problem was the trailers wire colors were not all consistent. I just installed the new stat to the same house wires as the original stat was, doing only one wire (matching stat colors) at a time so as to not loose track of anything.

Maybe twenty minutes.

TCNashville · 03-19-2015, 05:34 PM

Quote:

Originally Posted by Wrascal

Maybe twenty minutes.

We did this mod about 2 years ago and you're right, it was a short 20 minutes to complete. Couldn't be happier.

Wrascal · 03-29-2015, 08:46 PM

Just a follow-up. As the eBay seller was unable/unwilling to provide the correct/necessary fuse he decided to offer a complete refund and said keep it. Within one hour I was able to confirm with Coleman Recreational Vehicles that it uses the previously reported 2A/250V fuse.

Now I just gotta get over to Radio Shack; we've got two, each about 15 miles distance, that survived the recent shut-down.

And I gave him an excellent review for his generous solution.
http://www.ebay.com/itm/RV-COLEMAN-M...torefresh=true

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