BAC Forum
General Boards => Technical Support => Topic started by: Richard Muha on October 18, 2019, 04:20:56 PM
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Just bought 2008 Marquis. Furnace, Aqua hot works front of coach but not back. Only blows cool air on back. Thermostat set same temp for both locations on the furnace setting. Does same for heat pumps?
Any thoughts 💭
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Rich,
Check your zone pumps inside the Aquahot as is sounds like you are not getting hot fluid to the bedroom exchangers. Also gently tap on the "check valves" normally just above the zone (circulation) pumps.
If neither the heat pumps or AQ are working heat. you probably have a thermostat problem.
Steve
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I don’t really know where the zone pumps are on the Aqua hot. As far as thermostat goes, it seems to work fine for the A/C units.
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As Steve indicated... "inside the Aquahot." Take the outside door off by removing a couple of small screws and the several (3?) pumps will be there on the left side.
I do not know which Aquahot model you have, but this one is the one we have in our coach. You can download the manual for your Aquahot from aquahot.com.
http://www.aquahot.com/files/service_manual/AHE-100-02S%20Service%20Manual%20Rev.%20B%209-27-2011.pdf
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Thx. I believe I have the 600 D. I’ll check it out.
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Rich,
In the Coach Assist tech library (Private Members Only board) there is a link to all Aqua Hot manuals.
Steve
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Thank you. I’ll check them out. I must confess though, not very mechanically handy!
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Richard
Plan to attend a Beaver rally. There are plenty of folks there to do a walk through on these items.
When one lacks a background in repairs perhaps an Aqua Hot is a tough first start. To sit with someone and see what they are talking about as they explain it can make the understanding easier.
Remember, we all started as newbies.
BtW....there should be a label on the outside of the Aqua Hot box in the top right corner with the model and serial numbers.
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Thank you and I do plan on going to a event soon, if possible.
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Just bought 2008 Marquis. Furnace, Aqua hot works front of coach but not back. Only blows cool air on back. Thermostat set same temp for both locations on the furnace setting. Does same for heat pumps?
Any thoughts 💭
Richard, In your post you state that the heat pumps do not heat in the rear zones. Sounds like a thermostat problem. I assume that your coach has three roof A/C Heat pumps, which are separate from the Aqua Hot system..Might want to check out the thermostat before digging into the Aqua Hot.
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If you’re saying the rear heat pump isn’t working either, Richard, then the issue is more likely with the thermostat. But be aware the AC heat pump won’t work when outside temps get below about 43F; there’s not enough outside heat then to exchange (reverse AC) for. If the AC works fine, then yes, tapping the rear hydronics supply pump valve can dislodge it if it’s stuck and resolve the issue.
Joel
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Thanks to everyone that replied. My Marquis is a 41’ with only two 15,000 btu A/C heat pumps. Both do not come on at over 45 degree outside temps. I find it strange that the A/C works with both units using the same thermostat?
One other weird thing on the thermostat is that it has a zone 4 but no zone 3. Also zone 4 seems to do nothing except when I put it in furnace mode, the Aqua hot blower switch in bathroom (switch on), the floor vent fan in bath comes on and blows cold. If that zone is in any other setting the same switch does not light up or activate the fan.
I have a couple of other issues which I’ll post later. For those I have an appointment in Tucson November 6 at Empire CAT.
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Richard, Do you know if the two A/C Heat pumps are original or have been replaced. Sounds like somebody has got the units wired wrong or the dip switches in the units not set correctly. I have never replaced one but I understand that you have to get the exact replacement model for the ones you hav
Would be great if somebody had a wiring diagram and the dip switch positions for these coaches.
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In the Coach Assist section there are often helpful documents like this may prove to be, along with other troubleshooting and service manuals: http://bryantrv.com/docs2/docs/ccc5.pdf
From what I’ve read, not personal experience, I don’t believe the 5-button Duo-Therm (now Dometic) has dip switches for the heat pump, although newer models do, and there are dip switches for the other functions of the thermostat; just not the heat pump. The heat pumps communicate with the thermostats via a red connector at the red P3 plug in the control box. That’s for the outside ambient temperature sensor. If that connector is corroded, disconnected, or plugged to the wrong place on the board, I’m not sure the pump would even show up on the thermostat.
But I’m probably off course here because apparently the heat pumps do register on his tstats. Just sayin’ I don’t think there are dip switches for that specific function. But his issue with a thermostat controlling both units may be dip switch related.
Our coach lists a third zone on both thermostats even though there’s only two used, one each tstat. A third hydronics zone to me would be the bay.
Joel
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I turned on the heat pump for the rear last night in the master bed area. What came on was the floor vents with just cold air. I’ve had another RV with a/c heat pumps and they blow out the ceiling like the a/c. Something is way off here and certainly above my pay grade. I’m not that handy, + no way going on roof with two replaced hips.
Aqua hot seems to work up front and for now creates enough heat in the Coach, but the mornings here in Willcox Arizona are getting down to mid to high 30s. 🥶
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Richard,
Make sure your thermostat is set on Heat Pump and not Furnace. If it is, try the Furnace setting as someone may have crossed the wires when hooking it up. Not unheard of.
Roy Warren
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Ive tried both and with heat pump settings I get cool floor air front and back. On furnace I get aqua hot in front, and cool air on floor from rear. I cannot get anything from the heat pump roof. Only floor setting not matter what I set for heat. Both A/C work fine with individual settings.
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Richard,
You have 2 AC/Heat Pumps and 2 thermostats. While the owners manual isn't clear re zones, my guess is that each thermostat will operate it's respective AC/HP when zone 1 is selected. Not sure about the AH. I'd try Zone 1 in the rear and if no go, Zone 2.
You noted in a previous post that both ACs came on when you called for cooling with one of the t'stats. Assuming the other t'stat was off or set to a non-AC function, that doesn't sound right and would seem to indicate a wiring error.
Steve
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As Steve notes, there must be a wiring error. The Aquahot is a separate device and its floor vent fans should not activate when you turn on a heat pump that vents only via the ceiling ports. Your thermostats must have crossed wires.
But it's common when roof units are replaced these days, that new models don't mesh with 5-button DuoTherm thermostats, and many techs don't install things with that in mind. I'm guessing that's what's going on here.
Joel
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I have one thermostat that displayed zones 1, 2 & 4. Zones 1 works the A/C front of coach through the ceiling vents. It also works the Aqua hot in two floor vents. One located under the dash, the other under the galley. Zone 2 works the A/C through the ceiling properly in the bedroom area. Furnace and heat pump setting for zone 2 put cool air through the floor vents in the back bedroom area. Zone 4 seems to do nothing except when the Aqua hot blower switch is in the on position in the bathroom. The vent in bathroom then blows cool air on the floor vent. When both zones 1&2 are in the heat pump setting, only the floor vents throughout the Coach blow cool air. No action from the roof.
So, I guess the wires in the thermostat are messed up, but why does the Aqua hot not work in zone 2, yet works with same thermostat in zone 1?
Do I need a new thermostat or someone to rewire the existing one and what’s up with zone 4? I have but two A/C heat pumps on roof.
Frustrating!
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Your AC may have been replace and the unit may not have a heat pump
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That would be upsetting. Just bought the unit 10/7 and was told it had 2-15,000 btu a/c with heat pumps. Guess I’ll have to have someone get on the roof.. Aqua hot has two authorized service places in Tucson where I’ll be the month of November. I’ll put it on the list with the engine overheating and a small leak from something attached to the transmission. Dealer did say they would take care of those two issues. Getting a little heat on home front too! 🥵
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Richard,
From what you are describing, I think all the problems are at the thermostat and its hookup. I'd address that first. BTW, did the dealer replace either AC/HP? If so, I'd be on his doorstep. The Aqua Hot sounds like it is basically working but probably not getting a signal from the t'stat to turn on the zone pumps for the rear of the coach.
Good Luck, Steve
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They did not replace the a/c. Thanks. I believe it’s the thermostat too, after all the discussions. I’ll get it fixed.
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Richard,
I have a different year and model. That said, the thermostats (1 in the living room and one 1 in the bedroom) both show zone 1, 2, 3. We have had the coach for 7-1/2 years. I believe the thermostat is generic and is used for 2 roof units and 3 roof units. As far as I know, zone 3 is nothing on our coach. Our living room (zone 1) has vents as you mention, but also one under the refrigerator. Just as information.
Stan
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Richard,
One other thing you might look at is the AquaHot. There should be 2 or possibly 3 valves on the upper left that should get hot when you have heat selected. If only one is getting hot, the other has a flipper in the valve that may be stuck. Try rapping it a couple of times to see if you can get the valve to free up and then you should be able to feel both (or all 3) valves hot.
Roy Warren
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Richard
Some of what I suggest may have been mentioned, but this is my input.
We have an 08 Beaver Marquis, so I'm assuming you have three A/C/Heat pumps on the roof and One master thermostat with three temp sensors throughout living area of coach and one temp sensor in water tank bay.
Heat pumps should have nothing to do with floor registers.
Thermostate: There may be or should be four zones; three zones for living quarters need to be on "furnace", the forth zone "furnace" is for our rear bath and water bay but the water heat exchanger only operates through the selectable temp range that is in the bay.
If you do not have rear bath, you may just have three zones.
I suggest to make sure your thermostat control has all Three zones set on "furnace" and temperature selected above ambient temperature. If all fans come on throughout the coach, then your registers that do not provide any heat would indicate a circulation problem caused more likely by the zone circulating pump on the aqua hot and lets assume your aqua hot is providing the heated coolant either by electric elements or diesel burner.
In this mode, you need to access the aqua hot by taking off the hood to listen or feel if the appropriate circulating pump is operating. If it is not operating, try tapping on it which at times is effective.
In my opinion this is step one, and then proceed beyond this, if there is no resolution to the problem, as others have suggested.
Good Luck