Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×


Reply
 
Thread Tools Display Modes
Old 01-28-2017, 12:39 PM   #1
Member
 
Join Date: Feb 2015
Posts: 74
Changed t-Stat, something wrong

Researched on here but can't find answer. AC and heater run at same time.

Replaced Dometic Analog T-Stat with Honeywell RTH221B T-Stat,

Dometic wiring: Red-7.5V
Yellow-AC
White-Furnace
Blue-Hi Fan
Brown-Low Fan
Green-Ground
Connected wires to Honeywell: Red-taped
Yellow- "Y"
White- "W"
Blue/Brown- "G"
Green- "RC"
Did it this way as I read another article that wired it this way but was using a hunter T-Stat.

R and RC have a jumper that I left alone. Heater works great even with AC blowing air, Fan switch blows air. I tried AC auto switch both nothing happened. Leaving for work assignment next week, hope to get it fixed. Probably wrong wire placed but didn't experiment not wanting to mess something up. Thanks
Racer310 is offline   Reply With Quote
Old 01-31-2017, 10:27 AM   #2
Site Team
 
Join Date: Mar 2008
Location: Southwest Alabama
Posts: 9,850
It looks like you have it wired correctly.

Did you set the jumper for gas heat? Though I don't think that'd be the problem?

There's not a stray wire between the 'W' and 'G' terminals is there?
__________________
Salem 29RKSS Pushing a GMC Sierra 2500HD!
Gotta go campin!
Bama Rambler is offline   Reply With Quote
Old 02-01-2017, 02:20 PM   #3
Member
 
Join Date: Feb 2015
Posts: 74
I looked inside cover switch, it was on electric/heat pump, other one was gas so i switched it to gas last night and i think that fixed the problem. Will test tonight after doc appt. Thanks for the info, appreciate it very much.
Racer310 is offline   Reply With Quote
Old 02-01-2017, 03:07 PM   #4
Senior Member
 
B and B's Avatar
 
Join Date: Jun 2013
Posts: 10,833
Send a message via AIM to B and B
Remove the Jumper. The Heater and AC are totally separate units.
__________________
B and B
2022 Venture RV SportTrek STT 302 VRB Travel Trailer
2018 Heartland Landmark 365 Louisville 5th Wheel
2015 Heartland Bighorn 5th Wheel
2013 FR Rockwood 8289WS 5th Wheel
2012 FR Rockwood 2703 SS Travel Trailer
B and B is offline   Reply With Quote
Old 02-02-2017, 05:28 PM   #5
Member
 
Join Date: Feb 2015
Posts: 74
Thanks guys, it is fixed. Appreciate it.
Racer310 is offline   Reply With Quote
Old 02-02-2017, 06:04 PM   #6
Senior Member
 
Join Date: Nov 2016
Posts: 337
Quote:
Originally Posted by Racer310 View Post
Thanks guys, it is fixed. Appreciate it.
By what? Removing the jumper, or the switch to gas or both?
Mdaniels4 is offline   Reply With Quote
Old 02-02-2017, 06:18 PM   #7
Senior Member
 
Join Date: Jun 2012
Posts: 10,907
Quote:
Originally Posted by Racer310 View Post
Researched on here but can't find answer. AC and heater run at same time.

Replaced Dometic Analog T-Stat with Honeywell RTH221B T-Stat,

Dometic wiring: Red-7.5V
Yellow-AC
White-Furnace
Blue-Hi Fan
Brown-Low Fan
Green-Ground
Connected wires to Honeywell: Red-taped
Yellow- "Y"
White- "W"
Blue/Brown- "G"
Green- "RC"
Did it this way as I read another article that wired it this way but was using a hunter T-Stat.

R and RC have a jumper that I left alone. Heater works great even with AC blowing air, Fan switch blows air. I tried AC auto switch both nothing happened. Leaving for work assignment next week, hope to get it fixed. Probably wrong wire placed but didn't experiment not wanting to mess something up. Thanks
I understand you've gotten it working, but something about your wiring makes no sense. You say you taped off the red wire, which should be the positive power supply. so that makes no sense. You attached the ground wire to RC, which is where the positive power (red) wire should go to. I've attached a diagram for my RTH111B. The ground wire is unused because the old thermostat wasn't battery powered, so the positive DC voltage not only ran to the furnace and AC when the T-stat told it to, but it also powered the T-stat's brains, using the ground wire for return (negative). The furnace and AC have separate returns (negative) that don't go to/from the T-stat.

The T-stat is basically a switch that connects R to either W (furnace) or Y (AC) when called upon by the temperature. With batteries powering the brains, there's no need for a ground wire.

You'll see I also installed a switch to allow either fan speed to run.
Attached Files
File Type: pdf Thermostsat wiring.pdf (121.6 KB, 22 views)
__________________
1988 Coleman Sequoia - popup (1987-2009) - outlasted 3 Dodge Grand Caravans!
2012 Roo19 - hybrid (2012-2015)

2016 Mini Lite 2503S - tt (2015 - ???)
2011 Traverse LT, 3.6L, FWD
2009 Silverado 1500 Ext Cab, 5.3L, 4x4, 3.73
2016 Silverado 2500HD Dbl Cab, 6.0L 4x4, 4.10
rockfordroo is offline   Reply With Quote
Old 02-03-2017, 07:29 AM   #8
Site Team
 
Join Date: Mar 2008
Location: Southwest Alabama
Posts: 9,850
The difference is that you have a Coleman and he has a Dometic. Dometic, in their infinite wisdom, switches the negative side of the circuit and not the positive side. Therefore, you have to hook the negative wire to R/RC to get it to work.

The thermostat doesn't care because it's just flipping a switch (relay/triac) to make the connections.
__________________
Salem 29RKSS Pushing a GMC Sierra 2500HD!
Gotta go campin!
Bama Rambler is offline   Reply With Quote
Old 02-03-2017, 09:49 AM   #9
Member
 
Join Date: Feb 2015
Posts: 74
Took jumper out and left green wire to RC but only 1 unit worked. Green wire to R and the other unit worked. Put jumper back in and green wire back to RC, flipped a switch to gas (not electric/hey pump) and each unit worked. I think initial problem was not flipping the switch to gas. Thanks
Racer310 is offline   Reply With Quote
Old 02-03-2017, 12:09 PM   #10
Site Team
 
Join Date: Mar 2008
Location: Southwest Alabama
Posts: 9,850
Thanks for letting us know that you tried removing the jumper and it split the units, which is exactly what should have happened.
__________________
Salem 29RKSS Pushing a GMC Sierra 2500HD!
Gotta go campin!
Bama Rambler is offline   Reply With Quote
Old 02-03-2017, 03:50 PM   #11
Senior Member
 
Join Date: Jun 2012
Posts: 10,907
Quote:
Originally Posted by Bama Rambler View Post
The difference is that you have a Coleman and he has a Dometic. Dometic, in their infinite wisdom, switches the negative side of the circuit and not the positive side. Therefore, you have to hook the negative wire to R/RC to get it to work.

The thermostat doesn't care because it's just flipping a switch (relay/triac) to make the connections.
Aha! ("I see," said the blind man - as he picked up his hammer and saw!)

I'm assuming the furnace must also be wired to be switched on the negative side, then, too.
__________________
1988 Coleman Sequoia - popup (1987-2009) - outlasted 3 Dodge Grand Caravans!
2012 Roo19 - hybrid (2012-2015)

2016 Mini Lite 2503S - tt (2015 - ???)
2011 Traverse LT, 3.6L, FWD
2009 Silverado 1500 Ext Cab, 5.3L, 4x4, 3.73
2016 Silverado 2500HD Dbl Cab, 6.0L 4x4, 4.10
rockfordroo is offline   Reply With Quote
Old 02-06-2017, 11:17 AM   #12
Site Team
 
Join Date: Mar 2008
Location: Southwest Alabama
Posts: 9,850
That is mostly correct. There's a relay in the ceiling box that sends power to the furnace and that relay has the negative switched.
__________________
Salem 29RKSS Pushing a GMC Sierra 2500HD!
Gotta go campin!
Bama Rambler is offline   Reply With Quote
Old 02-06-2017, 11:30 AM   #13
Senior Member
 
Join Date: Jun 2012
Posts: 10,907
Quote:
Originally Posted by Bama Rambler View Post
That is mostly correct. There's a relay in the ceiling box that sends power to the furnace and that relay has the negative switched.
So how do they handle the furnace?
__________________
1988 Coleman Sequoia - popup (1987-2009) - outlasted 3 Dodge Grand Caravans!
2012 Roo19 - hybrid (2012-2015)

2016 Mini Lite 2503S - tt (2015 - ???)
2011 Traverse LT, 3.6L, FWD
2009 Silverado 1500 Ext Cab, 5.3L, 4x4, 3.73
2016 Silverado 2500HD Dbl Cab, 6.0L 4x4, 4.10
rockfordroo is offline   Reply With Quote
Old 02-07-2017, 10:04 AM   #14
Site Team
 
Join Date: Mar 2008
Location: Southwest Alabama
Posts: 9,850
There are relays in the A/C ceiling box for the A/C fan, compressor and one for the furnace. when in furnace mode, the relay powering the furnace, switches on and off in response to the thermostat switch opening and closing. So the thermostat powers the relay and the relay powers the furnace.
__________________
Salem 29RKSS Pushing a GMC Sierra 2500HD!
Gotta go campin!
Bama Rambler is offline   Reply With Quote
Old 02-07-2017, 12:03 PM   #15
Senior Member
 
Join Date: Jun 2012
Posts: 10,907
Quote:
Originally Posted by Bama Rambler View Post
There are relays in the A/C ceiling box for the A/C fan, compressor and one for the furnace. when in furnace mode, the relay powering the furnace, switches on and off in response to the thermostat switch opening and closing. So the thermostat powers the relay and the relay powers the furnace.
So they run the furnace T-stat wiring to the AC? Weird. If I were trying to follow the wiring, I would never have been expecting that.
__________________
1988 Coleman Sequoia - popup (1987-2009) - outlasted 3 Dodge Grand Caravans!
2012 Roo19 - hybrid (2012-2015)

2016 Mini Lite 2503S - tt (2015 - ???)
2011 Traverse LT, 3.6L, FWD
2009 Silverado 1500 Ext Cab, 5.3L, 4x4, 3.73
2016 Silverado 2500HD Dbl Cab, 6.0L 4x4, 4.10
rockfordroo is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Forest River, Inc. or any of its affiliates. This is an independent, unofficial site.



All times are GMT -5. The time now is 02:15 PM.