Attwood AC install

Topic: Attwood AC install (Read 2618 times) previous topic - next topic

Re: Attwood AC install

Reply #25 – September 09, 2019, 10:40:19 pm

You done for the night or no? Ill pm my number so I can run through the install. pretty easy..

Start with the front on
us the phone line to the thermostat for your harness to work the atwood.. make sure you have wires on each end labelled and connected correctly... there is a blue wire on the atwood(actually 2) .. find the aqua hot and (white wire mine was on the passenger side of the opening) connect that to 1 blue (doesnt mater which) and the other blue to ground.

text my guy about the 12v from the front.. waiting on him so I can tell you where we pulled or got it from.. I think it was already up there.

Ok he said the 12v was there already so use that 12v for front and rear mine was a white.. then you will need to fish another to the rear from the front..(these run the thermostat)

rear one you will need to run a new wire harness for thermostat down to the old sensor area and then to where you want to mount the tstat..

I think you have some wires crossed not a big deal but each AC will be separate except the 12v supply... like I said run the 12v from the existing living room to rear and the rest is getting the harness right and aquahot..

Re: Attwood AC install

Reply #26 – September 09, 2019, 10:54:47 pm

So it seems that these units are not set up to work together. The old Duo therm units had two thermostat inputs, and could send the signal to either. But these do not. Unless I am missing something, I think I will have to run them off 2 seperate thermostats.
Now just have to figure out how to run the wire and where to put the rear thermostat.

Re: Attwood AC install

Reply #27 – September 09, 2019, 11:03:35 pm

Quote from: Bob and Julie – September 09, 2019, 10:54:47 pm

So it seems that these units are not set up to work together. The old Duo therm units had two thermostat inputs, and could send the signal to either. But these do not. Unless I am missing something, I think I will have to run them off 2 seperate thermostats.
Now just have to figure out how to run the wire and where to put the rear thermostat.

Correct... front has its own thermostat as does the back and they do not talk to each other... I consider them married

Re: Attwood AC install

Reply #28 – September 09, 2019, 11:24:41 pm

I ordered a pair of Atwood's today, both with the heat pumps. I'm following these installs with great interest especially concerning the aqua hot hook up. I understand the Atwood's will have independent controls, with the current set up the front and rear aqua hot is controlled by the single control in front, I can understand using the current aqua hot wire on the front controller but what about the new controller for the rear, how does it connect to the aqua hot?

Re: Attwood AC install

Reply #29 – September 09, 2019, 11:48:50 pm

Quote from: Bill and Marsha – September 09, 2019, 11:24:41 pm

I ordered a pair of Atwood's today, both with the heat pumps. I'm following these installs with great interest especially concerning the aqua hot hook up. I understand the Atwood's will have independent controls, with the current set up the front and rear aqua hot is controlled by the single control in front, I can understand using the current aqua hot wire on the front controller but what about the new controller for the rear, how does it connect to the aqua hot?

Front and rear have a single aquahot wire at the opening.. AC has 2 blue wires.. connect 1 blue to the aquahot wire and the other to ground.. (doesnt matter which blue as they are connected to a relay) either blue to ground

Re: Attwood AC install

Reply #30 – September 09, 2019, 11:52:35 pm

This might help.. pretty simple once you get started

Duo Therm removal Atwood 15k install

there will be power wires and ground.... 1 wire for Aquahot... the front will have 12v available.. use that to run to the rear through the conduit. Next is the harness for the Tstat... can rewire existing phone line to work or run new harness to Tstat location.

Re: Attwood AC install

Reply #31 – September 10, 2019, 10:57:14 pm

Ah well thanks to David I got the AC going on both units tonight! Yah. Not sure if the furnace works yet. David I couldn't really tellwhich aqua hot wire was the right one because the wires near the aqua hot are yellowed and discolored and not every one has markings that I could see. But I took a chance on which one or a good guess and that seemed to work. So right now everything's cobbled together I have to finish the install crimp everything I had to solder a few connections. I had to add a 12 volt wire to the front AC and a 12-volt negative to the rear to get it all to work. Had to drill some holes through some of the roof beams and I ran the rear thermostat cable through the ductwork announce who won it around ducts in the back and I will end up putting the thermostat next to one of the three bulb lights on the passenger side there's like a little dresser cabinet. Tomorrow I will finished bolting everything down and caulk around the units get everything watertight. I'm pretty tired...

Re: Attwood AC install

Reply #32 – September 12, 2019, 11:23:28 pm

Okay well I'm having problems with getting the aqua hot to come on using the Atwood thermostat control. I've reviewed the wiring diagrams from both for travel and alcohol. And I'm pretty confident that I have it correctly wired. the blue wires from the Atwood go to both the ground wire that's connected to the frame just below the roof, and to the ground signal wire that goes to the aqua hot. When I turn on heat on the Atwood thermostat the heat pump comes on in the unit just as it should. When I then press the furnace button the Atwood turns the blower off, as it should, but the aqua hot fans do not turn on. This is for both the front and the rear unit. I use the Atwood thermostats on both the front and rear, on the front I use existing phone cable and connected to wires black to black red to red white to white yellow to yellow. and I'm pretty sure it's working right because all the functions on the unit other than the furnace are working. For the rear unit I use the Atwood cable, and again the furnace function is not working.
So I need some smart minds to look at this in a way that I'm obviously missing. The aqua hot is working I know that because if I use the separate bathroom thermostat it comes on and blows hot. And when I turn diesel on I get hot water. I checked the row of 12-volt fuses on the aqua hot and they all seemed fine I checked the 12-volt power across them and I'm getting it. so correct me if I'm wrong but it seems like the problem is in the atwoods relay. For some reason it's not sending a signal like it should. That's what the thermostat turn all the way up to 85 as well. Now this is Texas and it's hot as heck here and I saw something in the instructions about how below 45 degrees the Atwood would switch from heat pump to furnace. but others have been able to turn the furnace on by using that button so that shouldn't be it. I'm a little stumped at this point I guess I could call Atwood or dometic and I will but I'm not sure I'm going to get much help from them. Anyone have any thoughts?

Re: Attwood AC install

Reply #33 – September 12, 2019, 11:57:58 pm

Bob.. take the white wire you used to attach to one of the blue wires.. undo the connection and stick it straight to the ground connections on the frame (roof) .. aquahot should come on.. if not.. wrong wire or the relay is bad?

But to test the wires to make sure you have the right one just ground that wire by itself. Should kick on with no issue

Also if you can get a wire sniffer to check the wire is correct at the aquahot. It is really as simple as grounding the wire for it to work.. if that doesn't work .. make sure it has continuity

Re: Attwood AC install

Reply #34 – September 13, 2019, 12:00:40 pm

OK. I fixed it. Or at least I think I did.
The white wire needs to go to 12 volts not ground.
Looking at the Foretravel wiring diagram show wire A5 going from +12volt dc to the relay mounted close to the aqua hot. This has 5 pins. 2 of which are ground. one is the A5 coming from the ac area which is 12 volts. The other is A5A that goes from the relay to ground.
When I put 12 volts to the A5 wire the fans come on.
Same with A7 in the rear.
I haven't hooked it up to the attwood yet. Got to work the next 3 days, but will next week.
If it doesn't work through the attwood, then I will just install additional thermostats and be done with it. I also emailed dometic.
I could call Foretravel and ask them, and if doesn't work I will.

Re: Attwood AC install

Reply #35 – September 13, 2019, 12:31:46 pm

Bob, thanks so much for documenting your install issues with the Atwood's in regards to the aqua hot connection. I've ordered a pair and strongly considering doing the install myself along with a buddy, my main concern thus far in the research is the aqua hot hook up.
David's post was of great help as well. This forum is outstanding!!!

Re: Attwood AC install

Reply #36 – September 13, 2019, 01:23:36 pm

Quote from: Bob and Julie – September 13, 2019, 12:00:40 pm

OK. I fixed it. Or at least I think I did.
The white wire needs to go to 12 volts not ground.
Looking at the Foretravel wiring diagram show wire A5 going from +12volt dc to the relay mounted close to the aqua hot. This has 5 pins. 2 of which are ground. one is the A5 coming from the ac area which is 12 volts. The other is A5A that goes from the relay to ground.
When I put 12 volts to the A5 wire the fans come on.
Same with A7 in the rear.
I haven't hooked it up to the attwood yet. Got to work the next 3 days, but will next week.
If it doesn't work through the attwood, then I will just install additional thermostats and be done with it. I also emailed dometic.
I could call Foretravel and ask them, and if doesn't work I will.

Well that is a strange one.. here is a pic of mine.. Grounded. Blue is screwed to the frame of the roof.

Glad you got it.. Not sure I would want a run of HOT wire going all the way to the aquahot from on top of the roof?

Re: Attwood AC install

Reply #37 – September 13, 2019, 04:53:31 pm

The lesson we have learned here is the A/C sends a 12 vdc signal to start the Aqua Hot zone and a relay at the A/C converts that signal to a ground signal that actually starts the zone.

Now on 2004 and newer heaters that have the Electronic Control Board, a 12 vdc signal all the way from the A/C to the board starts the zone. No ground signal on newer heaters.

Re: Attwood AC install

Reply #38 – September 13, 2019, 05:40:10 pm

Quote from: Rudy – September 13, 2019, 04:53:31 pm

The lesson we have learned here is the A/C sends a 12 vdc signal to start the Aqua Hot zone and a relay at the A/C converts that signal to a ground signal that actually starts the zone.

Im no electrician by any means.. anything above a + - and I am lost so.. if you could help me to understand this..

As far as my understanding (very limited I will admit).. the instructions say to tie the furnace wire into either of the blue wires (on the AC) as they are both the same (meaning if it was used for ground it is a ground and if used for positive hot it is positive hot).. It is a relay that is installed in the AC so... does not create positive power nor does it make ground until the opposite end (other blue wire) is either grounded or tied to a positive wire.. As I understand it.. it is not capable of doing both Positive and Negative (only the one chosen by the installer)..

The relay acts as the switch to create ground for the aquahot system

Hope that was clear as to how I understand it works.. As stated.. I could be wrong

Re: Attwood AC install

Reply #39 – September 13, 2019, 06:25:40 pm

David, I think you have it right. Call me and we can get on same page.

7 one 3. 8 one 8. 3234

Re: Attwood AC install

Reply #40 – September 14, 2019, 09:10:09 am

Quote from: DavidS – September 13, 2019, 01:23:36 pm

Well that is a strange one.. here is a pic of mine.. Grounded. Blue is screwed to the frame of the roof.

Glad you got it.. Not sure I would want a run of HOT wire going all the way to the aquahot from on top of the roof?

David the wires already there. It's the white wire that in the front is labeled a5 and in the rear is labeled a7. These take a 12-volt signal which should come from the thermostat go through the air conditioning system back down the blue wire 2 the relays which then sends a signal to the a 5A or a seven a wire and that then turns on the aqua hot fan for that zone. The bath thermostat if you take it off the wall you'll see is a ground wire and a 12-volt wire which one connected sends a signal directly into the aqua high to turn that on for the bathroom zone. and remember this only turns on the fans not the actual aqua hot in order to do that you have to turn either the 120 volt circuit or the diesel circuit on. That was kind of confusing to me at first not sure why but it was.
Anyway what seems to be happening or not on my coach is the atwoods are not sending the 12-volt signal down the blue wire which then gets connected to that white wire that goes to the relay. I sent a service request through Atwood which is now dometic and their response was that I needed a service technician and there were none in my area. Which was pretty much what I expected from them. So my solution is to buy to Atwood thermostats like I have in the bathroom and place one in the bedroom and one in the front of the coach and all I need to do is connect one wire to ground and one wire 2 12 volt which would go to that a 5 wire the thermostat being the switching between. And then I'll just run an independent of the Atwood thermostat. Maybe it's just too hot here for the Atwood signal to come on? So I took a bottle of cold water and pressed it up against two sensor on the thermostat to see if that would help trigger it but it didn't do anything. I have one of the blue wires grounded so grounding the other wire should have turn the fan on right but it didn't. That's what Rudy had suggested I do and I figured well that's a good way to find out if it works or not. the only way I could get the aqua hot fans to come on was by supplying a 12-volt power to that a5 or a 7 wire. I really wanted it to work through the at with thermostat but something isn't working right and I don't know what it is. It's not my wiring with the thermostat because I have the Atwood wiring and the original for travel wiring on two different units and it's doing the same thing. I'm working this weekend so I'll work on it again next week maybe I'll know more by then.

Re: Attwood AC install

Reply #41 – September 14, 2019, 09:41:38 am

Bob, not saying it right or wrong.. I am trying to wrap my brain around this lol..

1st question is what aquahot model do you have?
2) have you traced the wire from on top to the aquahot..2 ways to do this.. 1 is to put a line sniffer on it and sound it out or take the number on the wire and go to the aquahot and remove the top cover and find it on the switches and relays.. front should be labelled LIVING ROOM ( BEDROOM for rear). once the wire is found that will show where it goes and what it does.

On mine (doesnt mean yours is exactly the same) has all the power fed to the aquahot and is a negative ground (guess could be common wire? Once grounded it completes the circuit ...

Cant see why they would need a positive in the roof to activate the switch at the pump when you would not have to. Just a ground would work on a relay in the roof..

Again. Not saying you are wrong but to wire it up that way is wrong on a few reasonings...what happens if there is a short in the wire in the ceiling? Extra costs and complexity of a Build..

Next would be impossible to make the 2 blue wires work by adding power to one side and negative to the other ( it will either short out or not work) as per the instructions they (blue wires ) are both the same.

I also had positive 12v in the ceiling ( I used for the 12v power on the thermostat).

Maybe we are talking almost the same thing here as I never traced the 12v poss wire to see where it originated but what I do know for sure is that the blue wire is a ground wire on mine that activates ground by the thermostat through the relay.

Re: Attwood AC install

Reply #42 – September 15, 2019, 12:41:28 am

David, this is the way it works far as I can tell.
12 volts is fed into the ac via the red wire. This energizes the tstat as well as the 12 v side of the ac.
When you activate the ac via the tstat, 12 v power is fed into the various relays. For the furnace this is via the blue wires.
One is ground the other is 12 volts from the relay I think. This sends power to the relay at the aqua hot. That sends the ground signal to the aqua hot I guess.
I tried grounding the wire out, as per Rudy's suggestion, and it didn't work. If it was turned on by a ground signal that would have done it.
So when I added 12 volts to that wire, it did turn on the aqua hot fans. Not sure why the Attwood is not sending the signal out to the aqua hot.
I traced the wires on the aqua hot. They feed into the top strip above the relays. I checked the power across. 12 volts.
I checked the fuses. All good.
I pulled and reseated the relays.
The only way to turn on the aqua hot fans on the units in the front and rear was to send 12 volts down that white wire.
So the only logical conclusion I can make is that it needs 12 volts to turn on.
The Tstat in the bath is a 12 volt wire on one side, and a ground on the other. Pull it and check it. 2 screws to pull it off.
Why the attwood is not sending the signal is a mystery to me, and dometic is no help. I am going to buy 2 cheap attwood tstats and run the heater fans off that. I will put one in the front and one in the rear.
As far as 12 volts running in the coach. There are tons of wires in my coach with power to them. 2 more won't make a difference.
Wish I knew why the attwood tstat wasn't working for me.
Bob

Re: Attwood AC install

Reply #43 – September 15, 2019, 09:12:10 am

so another thing I found while looking at my pics. There are jumpers on the AC board. They look like they are jumpered right but then again, maybe not. Might have to get back on the roof and check it out. Nothing in the paperwork about it, but on the schematic you can see it. Its the two jumpers that are up top of the board in the middle. They say fur off fur on. I again emailed dometic customer support about this.

Re: Attwood AC install

Reply #44 – September 15, 2019, 10:52:07 am

Let us know what they say when you call them ( Dometic).

I agree with most of what your saying ..Let me see if I am getting this right.. I have 12v coming into and connected to the 12v needed at the atwood... Nothing else is connected to that 12v lead.... Now on mine.. 1 blue is ground 1 blue is connected to aquahot white wire... thermostat activates the relay Via the 12v into the AC (when you put the thermostat into furnace mode) which then grounds the white wire Via the relay.

So my question is this.. do you have 12v Pos to 1 side of the blue wire and then the aquahot to the other blue wire?

Re: Attwood AC install

Reply #45 – September 15, 2019, 10:29:26 pm

Quote from: DavidS – September 15, 2019, 10:52:07 am

Let us know what they say when you call them ( Dometic).

I agree with most of what your saying ..Let me see if I am getting this right.. I have 12v coming into and connected to the 12v needed at the atwood... Nothing else is connected to that 12v lead.... Now on mine.. 1 blue is ground 1 blue is connected to aquahot white wire... thermostat activates the relay Via the 12v into the AC (when you put the thermostat into furnace mode) which then grounds the white wire Via the relay.

So my question is this.. do you have 12v Pos to 1 side of the blue wire and then the aquahot to the other blue wire?

You can't call them. Only email.
The way I see it, the relay in the AC unit sends a 12 v signal when furnace is called for, but I haven't been able to get it to do so. I may be wrong about this but seeing that the fans come on when I apply 12 volts to the aqua hot wire..... Don't think I'm wrong.
I plan to pull the cover off the AC units and check that jumper. Might be that it's wired incorrectly. Looking at the pics, the blue wire goes in one side of a white relay and out the other side to be connected to the aqua hot wire.
The other puzzle is that the manual show both blue wires going to the furnace, not one to ground. But the aqua hot only has one wire from the AC to the relay on the aqua hot.

Re: Attwood AC install

Reply #46 – September 16, 2019, 12:28:45 am

Quote from: Bob and Julie – September 15, 2019, 10:29:26 pm

You can't call them. Only email.
The way I see it, the relay in the AC unit sends a 12 v signal when furnace is called for, but I haven't been able to get it to do so. I may be wrong about this but seeing that the fans come on when I apply 12 volts to the aqua hot wire..... Don't think I'm wrong.
I plan to pull the cover off the AC units and check that jumper. Might be that it's wired incorrectly. Looking at the pics, the blue wire goes in one side of a white relay and out the other side to be connected to the aqua hot wire.
The other puzzle is that the manual show both blue wires going to the furnace, not one to ground. But the aqua hot only has one wire from the AC to the relay on the aqua hot.

Basically what you seeing is the completion of the Circuit in question.. whether its with ground or positive is the un aswered part.. ..

In theory ( as mine is wired) ..Aquahot has all the power it needs in the basement.. why run a hot wire all the way through the roof?

Let us know what you find.. interesting to say the least.. still thinking something is not correct... but at the end of the day .. could be correct.

Re: Attwood AC install

Reply #47 – September 16, 2019, 07:40:10 pm

Still not working. Response from Dometic

Dometic does not have a consumer technical support department. Authorized service centers and/or dealers provide all technical support. They are trained and certified on Dometic products to be able to assist you. They will trouble shoot, diagnose your unit, and contact Dometic to obtain authorization to provide warrantable repairs if applicable. The only thing we can do is send you installation/operating manuals.

As I suspected, they are no help.
No ground signal is coming from ac. Resistance with heat and furnace on is very high.
This weekend I did a lot of research and found that yes it's a ground signal that turns it on, which Rudy and David already informed me, but the attwood is not connecting that to the aqua hot. Also it's a puzzle why the aqua hot comes on with 12 volts applied to the signal wire.
I am going to call aqua hot tomorrow. See if they can shed some light on this. Otherwise I'm going to put in 2 tstats and call it done.

Re: Attwood AC install

Reply #48 – September 16, 2019, 07:58:55 pm

Think you swapped front and rear? swap thermostats and see if that helps.. Worth a try.

Re: Attwood AC install

Reply #49 – September 16, 2019, 08:56:27 pm

Quote from: DavidS – September 16, 2019, 07:58:55 pm

Think you swapped front and rear? swap thermostats and see if that helps.. Worth a try.

Nah. Neither one works for furnace.
I did some more tracing of the wires and found the relays that fortravel puts in for the aqua hot. I thought the relays on the aqua hot were what they were talking about but they're not. all the wires check out there is continuity there's power there's ground so it's got to be in the Atwood board. For some reason when the thermostat calls for the furnace it's not sending the signal through. And since it's in both units something else has got to be going on right? One of the things I was thinking about doing was switching out the jumper on the electrical board and seeing if that did anything and if it did that mean that the jumpers are wired wrong. or the other thing is that it's just too hot and the internal sensors won't turn the furnace on even with the temperature up to 85 degrees. Or I got lemons.

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