jleamont Report post Posted November 1, 2020 (edited) Does anyone have any experience with the 5 button thermostat and troubleshooting it? I left the power switch turned on, ac-heat pumps off and the was coach plugged in for a month ( not something I would normally do). Today the thermostat will not turn on, completely dead. I tried all of the reset procedures and pulled the tops off the ac units, checked fuses, no issues. This is the original thermostat so it was installed July 2001. On the roof are two Dometic Penguins with heat pumps also original equipment. I plugged it in at the ac unit to eliminate the possibility of the phone type cord being the issue somewhere between the thermostat base and the AC units, it still will not power up. Edited November 1, 2020 by jleamont Share this post Link to post Share on other sites
manholt Report post Posted November 1, 2020 Your board looks good. Does it have a battery back up? What does the backside of the board look like (post a photo). Share this post Link to post Share on other sites
wildebill308 Report post Posted November 1, 2020 That looks a lot like my thermostat so this should be interesting. I haven't pulled my cover off yet. Does it have a fuze under the cover? On my old Bounder when the thermostat acted up I would pull the fuze and it would re set and work. Maybe you can disconnect it interrupt/reboot the power and see if it helps. Bill Share this post Link to post Share on other sites
huffypuff Report post Posted November 1, 2020 Does it smell burnt? Upper left has a spot on the other side. Share this post Link to post Share on other sites
manholt Report post Posted November 1, 2020 Eagle eye Ray! Joe, unscrew the CB and look on other side. Share this post Link to post Share on other sites
jleamont Report post Posted November 1, 2020 (edited) I didn’t see anything burnt and it doesn’t smell burnt. I pulled the board from the housing and I rechecked it, and that blemish is between the board layers. Here’s a photo. I did pull the manuals out and located a troubleshooting guide in the back. I will give that a shot today to see if I have power coming to it. Within that phone type cable is a black and red wire. Black is negative and red is positive. Now comes the tricky part, trying to see those tiny wires. Edited November 1, 2020 by jleamont Share this post Link to post Share on other sites
jleamont Report post Posted November 1, 2020 Ok, everything is pointing to a bad thermostat. I have power and ground coming out of the control board and down (phone cord) into a junction at the bedroom AC unit. From the junction it has a phone cord running through the wall to the thermostat. I unplugged it at the junction and plugged the thermostat in NOTHING. Since I have power and ground it should at the very least light up, but it’s still dead. I ordered a thermostat, I was a bit surprised they still make the exact same one. I’ll have it Tuesday. Oddly in the manual it says the thermostat life expectancy is 10-15 years. Who would have thought? Share this post Link to post Share on other sites
rayin Report post Posted November 1, 2020 Everything has a lifespan. I hope my thermostat never fails during what's left of my RVing life it is obsolete, NLA Share this post Link to post Share on other sites
manholt Report post Posted November 1, 2020 19 years old...got your $$$ worth! Share this post Link to post Share on other sites
jleamont Report post Posted November 6, 2020 (edited) Helpful information, here is where to check for power on a 5 button thermostat. Interesting fact, the RJ11 cable is the same as a phone cable EXCEPT; On a phone cable the pins transpose on each end, on the Dometic cable if you set each plug on top of once another they should pin out identical. So you have to cut one end off and flip the wires OR take the junction block apart and flip the pins inside of it. You can use a standard RJ11 phone cable with little modification. Edited November 6, 2020 by jleamont Share this post Link to post Share on other sites
manholt Report post Posted November 8, 2020 OK, did you fix it? Share this post Link to post Share on other sites
jleamont Report post Posted November 8, 2020 Yup, all fixed up and working! The thermostat took longer than expected. Probably should have ordered it from Amazon. I went with the local dealer (place I sent you for the transfer switch). I felt they probably needed my business more than Amazon. Share this post Link to post Share on other sites
manholt Report post Posted November 8, 2020 This year, I would think so...I have tried to shop locally as much as possible! Glad you got it done. Share this post Link to post Share on other sites
shyde555 Report post Posted December 23, 2020 I wonder if the thermostat might be my problem. Furnace blows but won't fire. Just blow's cool air. Share this post Link to post Share on other sites
jleamont Report post Posted December 23, 2020 shyde555, Welcome to the FMCA Forums! What make and model furnace do you have? Do you have two furnaces, if so does the other one function properly? Share this post Link to post Share on other sites
wildebill308 Report post Posted December 23, 2020 14 hours ago, shyde555 said: I wonder if the thermostat might be my problem. Furnace blows but won't fire. Just blow's cool air. Welcome to the forum. Like jleamont said we need some more information. If you put that information in your signature file (see jleamont's) you don't have to do it everytime you ask a question. Now just guessing but make shure the thermostat is in the right "mode" and the right "zone" and temp is set high enough for it to turn on. Something else is when a propane furnace turns on it has a "purge cycle" if the sail switch doesn't move enough to make contact it won't light. Let us know what you find out. Bill Share this post Link to post Share on other sites
hermanmullins Report post Posted December 23, 2020 (edited) On a Aqua Hot unit, when it is on and heat is required the blower will come on to clear the unit of any fumes. Then it will ignite produce heat until the the heat is no longer required. When the unit shuts down the flame will go out and the blower will blow until it chamber has cooled down then the blower will stop. This is how it was explained to me by several AH techs. An that is how mine works. Herman Edited December 23, 2020 by hermanmullins Share this post Link to post Share on other sites
wayne77590 Report post Posted December 23, 2020 (edited) My Aqua Hot is different. I have the 400-D series. (2015) The heat ex-changer at the register has a fan. It comes on when the demand is there (only takes a few seconds for the Aqua Hot to produce heat to pump. The heat ex-changer receives the hot coolant through the piping and returns it to the AH. The fan in the heat ex-changer is the force for the hot air to flow out of the register. That was the way it was described to me. From my manual: My bolded text "Thermostats: The interior room thermostat can be set at the desired temperature; therefore, whenever the interior of the room “calls for heat”, the Aqua-Hot’s circulation pump and interior heat exchanger fans will be activated. The fresh water thermostat controls the bay heating area and should NOT be set below 40°F, to prevent freezing of the domestic water storage system. Please contact the specific motor home dealer for exact location of thermostat controls." Also contact dealer or manufacture for model of Aqua-Hot. Manuals do change. Edited December 23, 2020 by wayne77590 Share this post Link to post Share on other sites
Wecamp4fun Report post Posted May 18, 2022 I've got similar problem...thermostat not displaying. Checked fuses and all good. Ordered a replacement from Micro air and tried it and no display. I'll check my old thermostat solder connections on board when I get home to see if I have 12vdc. When I turn the thermostat on and try to run the hurricane heat, only the bedroom fan control works and puts out heat. The 2 over the door for the living room and galley don't run and no heat comes out vent. Not sure if this is related or not but this symptom showed up when the thermostat display died. Anything else I can try before i take it to a shop for troubleshooting? 2002 Country Coach Intrigue Dual penguin AC/heatpumps Share this post Link to post Share on other sites
wildebill308 Report post Posted May 19, 2022 18 hours ago, Wecamp4fun said: When I turn the thermostat on and try to run the hurricane heat, only the bedroom fan control works and puts out heat. The 2 over the door for the living room and galley don't run and no heat comes out vent. Not sure if this is related or not but this symptom showed up when the thermostat display died. What is "hurricane heat" is that the furnace or the heat pumps? Bill Share this post Link to post Share on other sites
Wecamp4fun Report post Posted May 19, 2022 5 hours ago, wildebill308 said: What is "hurricane heat" is that the furnace or the heat pumps? Bill Yes that is the diesel burner furnace. Newer models use Aquahot or similar. Mark Share this post Link to post Share on other sites
hermanmullins Report post Posted May 19, 2022 If I am not mistaken Hurricane unit are owned by Aqua Hot. Or maybe it's Hydro Hot I'm thinking of. Herman Share this post Link to post Share on other sites
wildebill308 Report post Posted May 20, 2022 On 5/18/2022 at 3:46 PM, Wecamp4fun said: The 2 over the door for the living room and galley don't run and no heat comes out vent. Not sure if this is related or not but this symptom showed up when the thermostat display died. I haven't seen diesel burner, furnace heat that came from the celling. I have never seen heat from the diesel furnace coming from celling only heat from the heat pumps. Cheech your thermostat and make shure you have the correct "mode" in each "zone". I am thinking you have at least 2 zones. Bill Share this post Link to post Share on other sites
Wecamp4fun Report post Posted May 20, 2022 15 hours ago, wildebill308 said: I haven't seen diesel burner, furnace heat that came from the celling. I have never seen heat from the diesel furnace coming from celling only heat from the heat pumps. Cheech your thermostat and make shure you have the correct "mode" in each "zone". I am thinking you have at least 2 zones. Bill The heat does not come from the ceiling for the furnace, the controls are above the door for the living room and galley areas. There are 2 fan switches that push the air in the ducts at floor level depending on the speed set. These 2 do not work but the bedroom one does. My MODE is in FURNACE because the bedroom one kicks on and works. I can't see the display to confirm that but have no way of knowing for sure what MODE I am in or what t he temperature is or if I'm only controlling ZONE 2 which is the bedroom. ZONE 1 could be set different and that is why it won't work up front. Hurricane heater works. Fires up and puts heat in bedroom so I know that is not an issue. The issue lies with the thermostat and not being able to see what MODE each zone is in. Does not display on either old one or the new Micro air RV thermostat. Yes it is the correct replacement for the 5 button old one. I'm leaning to bad phone cable connection somewhere went bad. I've pulled the inside cover down in bedroom AC unit to see the phone cables and have unplugged and replugged them in several times as well as at the thermostat itself but have not tried the individual wires within the cables. I'm not sure which cable goes to/from thermostat and the AC unit. All fuses in AC units on roof are good. I did try the solder connections on the old thermostat with the phone cable plugged in like referenced above and got no voltage. So that tells me the thermostat itself is not getting power. I'm just not sure where to go from here. I may have to get it to a shop where someone with electronics troubleshooting can look into it. Thanks for all that are trying to help. Much appreciated. Mark Share this post Link to post Share on other sites
wildebill308 Report post Posted May 21, 2022 Have you pulled the cover off the thermostat and looked to see if there is a small 12v fuse in there or one near it providing 12V power to it. Bill Share this post Link to post Share on other sites
