Aqua hot not working on heat strips?

[Texomaman73]

My 2000 Monaco Executive has the dual aqua hot system and it heats the coach on diesel just fine.  After the coach comes up to temp, to the best of my knowledge it is supposed to switch to the heat strips to maintain temp and then automatically switch back to diesel if the heat strips can not keep up with the temp. 

It is plugged into a 50 amp service and when first turned on the diesel burner heats the unit up and then it shuts off and the room fans all keep running.   Later I check and the room temp will have dropped and I can feel the water supply lines in the coach and they are cold to the touch and the room fans are all still blowing cold air.  

I have all three zone thermostats set to furn and for the unit to maintain 70!  I have the basement temp set to the max (50) and it too is not heating.  

I am a new owner of this unit and a newbie to RVing!  Instructions for the use of the heating and AC are vague to say the least so I am wondering what I am missing!  Any and all help will be greatly appreciated! 

Jeff

[Guest Ray Davis]

As I understand it doesn't exactly switch to elect rather the elect is set to come on at a slightly lower temp than the diesel so to operate as you describe           both switches must be on .  

Are you leaving both elect and diesel switches on ?  

[jfbolkovatz]

Beside, both switches on, is the 120V breaker tripped? Third there is a 3amp fuse in the bedroom closet 12V panel that powers the relay for the  120V AH heating element.

Another possibility is the thermostat on the 120V heating element. I'd call an AH specialist and ask for suggestions. John Carrol. (sp)

JoeB 03 Exec PBDD

[Texomaman73]

22 minutes ago, Ray Davis said:

As I understand it doesn't exactly switch to elect rather the elect is set to come on at a slightly lower temp than the diesel so to operate as you describe           both switches must be on .  

Are you leaving both elect and diesel switches on ?  

I am not aware of a selector for diesel and/or electric, mine only has a switch that says aquahot!  

 

[96 EVO]

It has a switch somewhere that turns on the electric element.

[Texomaman73]

4 minutes ago, jfbolkovatz said:

Beside, both switches on, is the 120V breaker tripped? Third there is a 3amp fuse in the bedroom closet 12V panel that powers the relay for the  120V AH heating element.

Another possibility is the thermostat on the 120V heating element. I'd call an AH specialist and ask for suggestions. John Carrol. (sp)

JoeB 03 Exec PBDD

I was about to go out and look for the switches you and Ray are talking about and check fuse, but it started pouring so I will wait until it lets up to investigate

3 minutes ago, 96 EVO said:

It has a switch somewhere that turns on the electric element.

I don't doubt I am missing it somewhere!  It took me tries to find the carbon monoxide detector!  It was located on a base plate in the kitchen and I had to basically crawl on my belly to find it.  I will look again for this switch!  Where are yours located to give me a starting point?

[96 EVO]

Mine is a little later model, and Aqua hot grouped the 3 switches together on a single panel on a livingroom cabinet wall.

Your electric switch 'may' be labeled water heater, and could be in the kitchen. Possibly under the kitchen counter.

[Ivan K]

Our 2000 Sig might be similar to yours and the switches are in the kitchen, look like this pic. The single electric element can't keep up in cold weather and diesel burner should kick in again as needed, if left ON.

[Texomaman73]

1 hour ago, 96 EVO said:

Mine is a little later model, and Aqua hot grouped the 3 switches together on a single panel on a livingroom cabinet wall.

Your electric switch 'may' be labeled water heater, and could be in the kitchen. Possibly under the kitchen counter.

 

1 hour ago, Ivan K said:

Our 2000 Sig might be similar to yours and the switches are in the kitchen, look like this pic. The single electric element can't keep up in cold weather and diesel burner should kick in again as needed, if left ON.

I

You guys are great! 

I found my switch in the kitchen and it has the same nomenclature on it as above pic!  I turned it on and started the diesel burner again to bring it quickly up to temp so I can check and see if it continues to heat when burner shuts off.  If not I will look for the fuse, but my hope is that this was the fix!  I really appreciate the help and I will update tomorrow if it is working like I think it should be!

[Guest Ray Davis]

I don't believe the fans should keep running after the heat cuts off , mine doesn't .

[Texomaman73]

16 minutes ago, Ray Davis said:

I don't believe the fans should keep running after the heat cuts off , mine doesn't .

Well mine does!  It would make sense that the fans would shut off, so I guess that I have another issue to boot!  

Anyone have any ideas on this issue?

[96 EVO]

Yeah, there is definitely a problem.

The diesel burner should have fired back up long before the heat exchangers continued blowing till the air was cold.

Remember, your diesel system needs to be able to work even if you are not plugged in to shore power, so it works completely independent of the electric element.

[Guest Ray Davis]

 With the fans staying running I wonder if it is not actually reaching the desired temp and the burner is shutting down for some reason .

 The thermostat would still be calling for heat and the fans would still be running . 

 If you want to learn more about the Aqua Hot system go on this link

 http://rvhydronicheaterrepair.com/

 His name is Roger Berke , there are other repair people around as well .  I sent my burner to Roger one time so he could go through it ,   he charged me 200 plus parts but that was a number of yrs ago .

 

Edited October 26, 2020 by Ray Davis

[Ivan K]

If his 70F thermostat preset temperature has not yet been reached and AH fluid is already cooling down, the fans and pumps will keep running and blowing cold. I suspect that the diesel burner was turned OFF after the initial cycle. On the early AH systems with a single electric element, there is no way to keep the fluid hot without burner when used for heating in cold weather. If burner is turned OFF or fails to ignite, you wake up to a cold air. Been there.

[Guest Ray Davis]

Ivan , that's a likely scenario and essentially what I said except you have him turning the burner off himself .    After reading his original post again you are      probably right .   Maybe he will answer back with more details 

[96 EVO]

1 hour ago, Ivan K said:

If his 70F thermostat preset temperature has not yet been reached and AH fluid is already cooling down, the fans and pumps will keep running and blowing cold. 

My heat exchanger fans won't come on until there is sufficient heat in the boiler fluid, and if running on electric alone, they will occasionally shut down long enough for the electric element to catch up, then they will come on again. 

This will happen even while the thermostat is calling for heat. 

As was recently replied to your thread on IRV2, there's a good chance your low temp thermostat in the boiler tank has failed.

I believe that is what signals the burner to re-fire when the boiler fluid get's cool, and tells the heat exchanger fans to shut down if the fluid get's cool.

[Ivan K]

54 minutes ago, 96 EVO said:

My heat exchanger fans won't come on until there is sufficient heat in the boiler fluid, and if running on electric alone, they will occasionally shut down long enough for the electric element to catch up, then they will come on again. 

Your later AH version is obviously more 'intelligent' than ours, our fans will come on when ever called on by the thermostat setting regardless of how cold the fluid is, and it is cold today since it was off for a couple of weeks now. I just now tested it to be sure. Our fan/pump relays look like an afterthought the way they are installed in the AH box and have no connection to the boiler fluid thermostats. I really have no problem with the way it works, we just keep both switches ON when we use it for heating.

[Guest Ray Davis]

 Ben , your system is obviously a little more sophisticated than mine .    Mine is like Richard's I have 3 wall thermostats 1 for each zone and as soon as I move   the lever to ask for heat the fans come on even when everything is cold .   My Windsor is an 03 and the OP has a 2000 so our Aqua Hots are probably similar  So his fans can probably run even with no heat like mine . I think Ivan has the most likely scenario and the OP just needs to get used to the way his operates    He also will learn that the elect part is pretty weak .     It doesn't have heat strips it is more like a water heater element so he can have hot water and a     little heat without firing the diesel .

[Texomaman73]

Well been monitoring all day and this is what I see!  The diesel comes on and heats the lines up to a hot feel to the touch and the coach will come up to temp desired.  Then the fans will individually shut off in the rooms as they come up to temp, after all have reached temp the boiler apparently shuts off but I can still hear noise coming from the aqua hot system and there is still exhaust coming out but it isn't near as hot as when the boiler is on.  

Does the AH still have exhaust when running on heat strip?  The amount of air seems much less then when the diesel is running, is this normal or is this an indication that the burner has shut itself off.  

I'm not sure if it is working at this time, but since I turned it on earlier today the coach has stayed at desired temp but the lines don't feel near as hot as before and the thin light on top of the AH switch came on.  

I'm still confused and am going to check out the link Ray shared.

Thanks for all the help, I do feel like I am slowly getting a better understanding of the AH.

Jeff

[Ivan K]

Your exhaust air should stop after 3 minutes or so. It is just to cool the combustion parts down. We don't have the narrow light do I can't comment on its meaning. Watch for the burner starting up again on its own after the coolant temp triggers low temp thermostat at the boiler tank, if it does.

[Texomaman73]

1 minute ago, Ivan K said:

Your exhaust air should stop after 3 minutes or so. It is just to cool the combustion parts down. We don't have the narrow light do I can't comment on its meaning. Watch for the burner starting up again on its own after the coolant temp triggers low temp thermostat at the boiler tank, if it does.

It has been pouring here all day so I will run out and check and maybe I caught the exhaust after it had shut down.  I was thinking that the thin light on top meant that it had come up to temp, but that is just a guess!  

 

[96 EVO]

38 minutes ago, Ivan K said:

Your later AH version is obviously more 'intelligent' than ours, our fans will come on when ever called on by the thermostat setting regardless of how cold the fluid is, and it is cold today since it was off for a couple of weeks now. I just now tested it to be sure. Our fan/pump relays look like an afterthought the way they are installed in the AH box and have no connection to the boiler fluid thermostats. I really have no problem with the way it works, we just keep both switches ON when we use it for heating.

Ah, I see!

Learn something new every day!

[Guest Ray Davis]

Now with the diesel off let it cool down until the water is cool then turn the 120v water heater sw on and it should make hot water .     It may take a little  while for the water to get hot but it should start feeling warm after 15 min or so maybe sooner .

[Texomaman73]

32 minutes ago, Ray Davis said:

Now with the diesel off let it cool down until the water is cool then turn the 120v water heater sw on and it should make hot water .     It may take a little  while for the water to get hot but it should start feeling warm after 15 min or so maybe sooner .

Just got back in and it had cooled down from 65 to 58 the thin light was on and the fans were still blowing and the line was cooler.  I checked the breaker box in the bedroom and the breaker for the AH heater (opt) was off so I turned it on and re-fired the boiler.  Coach is about up to temp will check back in a while and see if it is staying on.

I will let it (hopefully) run all night, if it is cool in the morning, I will do as you are saying.  Will the aqua hot light come on with just the electric switch on?

[Ivan K]

I am not quite sure if you keep turning the diesel burner OFF or not but if you want to have a warm night, keep both switches ON. Electric alone will likely not do for a chilly night like we have here in N TX today. Not with a single electric element in that era AH.