Question about hot water heater

[bigcitybob]

Sorry to ask another question but being new owners of a 2006 Prevost Country Coach XLII, we had questions about the Message Center Display yesterday about the low coolant and got it diagnosed and fixed thanks to all of the replies. Suddenly today we have no hot water. This is our maiden voyage so I guess we are learning things by on the job training! I doubt this can be related to the low coolant issue. We tried checking all the breakers, that didn't seem to fix it. We have AquaHot and that seems to be working. Can't figure out what changed or happened. We are about a week into our trip and it will be pretty tough taking cold showers if we can't figure it out. Any thoughts or help you can offer would be greatly appreciated!

Thanks so much!

Bob Baumann
2006 Country Coach XLII

[Joe Camper]

Hey Bob morning.

2 questions first, how R U sure the aqua hot is still working.

Second R U aware that the aqua hot also has an electric heat source, do U know where the switch is and have u also tried that?

[Pete]

Bob, do you have hot water in your sinks? You mentioned not having hot water for showers. If it is only in your shower it could be your mixing valve.

[bigcitybob]

The AquaHot dispenser in the sink is still very hot. We have tried the breakers but don't know where any other switches might be. Any thoughts?

[bigcitybob]

We don't have any hot water anywhere - not in the shower or sinks. Just the AquaHot dispenser in the kitchen sink. Any ideas would be appreciated.

[Joe Camper]

U need the help of a CC POGer to help u get a better understanding of the house systems on yours.

Who did U buy it from they may help.

I think it may be operator error. Either that or the aqua hot is not working as correctly as u think it is. There is at least 3 different ways to make hot water.

If u R moving around the engine should make plenty of domestic hot water. Right? or no, or your parked.

Wheres the CC contingent bus driver in need of warm showers.

[JIM KELLER]

Big Bob, Do you have a Crestron system on your Bus ? I would like to help but if you do I'm out.

[Gil_J]

Bob,

As you probably know the AH has four sources of hot water. One is 120VAC, one is the AH's diesel fired burner, one is the engine's coolant loop and the forth is a hybrid that uses both 120VAC and the diesel fired heater. You mentioned the AH was producing hot water only at the sink. I'm betting that is from an instant hot water heater and not from the AH.

Okay, the 110V breakers are on, that's good. Know you need to find the low voltage control switch. This could be a switch, probably located up front. If you have a Crestron controller, it could be on it. There should also be a switch to activate the diesel burner. On older CCs you would have to have on the electric hot water switches and a switch labelled central heat control or something close to that. It's possible you have the AH control panel. If so, it will have a switch for electric heat and one for diesel fired heat.

Do you have the CC manual? CC did a pretty good job with their earlier manuals. It should be in the manual, but may take some looking to find it.

[bigcitybob]

Yes - the bus has the Crestron system. Thank you for your willingness to help - I appreciate it.

[bigcitybob]

I will check out what you have described. I am wondering if has something to do with the engine's coolant. We got a message center display for the coolant and when adding additional coolant to the system discovered that the cap was very cracked. It seems like we had hot water up until the time I added the needed coolant.

Yes - it comes with a ton of manuals but they are not really very user friendly and they haven't been much help. We have had three people reading through them trying to find solutions and everyone has agreed that they are difficult to find what you are looking for and not very helpful.

Thanks so much for your response. I will check out what you have mentioned. Yes - it does have the Crestron system.

[Gil_J]

If the coolant is low in the AH, that could be the problem. AH has its own coolant loop, not shared by the engine. FYI, the is also an engine coolant loop.

[Pete]

Bob, this may sound very elementary, but by reading your post, are you talking about the kitchen sink having hot water? Are you mistaking the A/H (aquahot) for an Insta Hot in the kitchen sink? Maybe some pictures posted would help us help you. (post an actual picture of the Aquahot so we could be sure you are talking about an Aquahot). Post a picture of the device in the kitchen sink you are calling an AH, which may be an Insta hot. This would give us a starting point to help.

[dale farley]

Bob, I realize we are all somewhat guessing at the root of your problem, but since you had hot water when you ran the bus, it sounds like you have never hit the right buttons to cause the 110v hot water to come on after shutting down the engine. My CC had two switches for the hot water heaters. My current coach has one switch for the 110 V hot water. I feel almost certain you have a switch at some place on the dash or another panel if not in the Creston itself. When you run the bus, the engine automatically heats your hot without you making any adjustments, but when you stop the engine, you probably have to tell the system you need hot water. I had the same problem the first trip I went on after purchasing my CC.

[Jamie Bradford]

Has this issue been discussed with Miles?

[JIM KELLER]

Has this issue been discussed with Miles?

Good point Jamie. Big Bob, if you do not get this issue resolved and still want help post your cell # and we will get Miles to contact you.

[billbunch47]

Not being a CC owner but I think we are missing the big picture here. I thought CC had a Wabesto unit and two electric water heaters ?? and in his case a Insta hot at the sink, sounds like a breaker or switch issue to me. But it also sounds like a good Miles question.

[Reagan Sirmons]

You gentlemen know much more about this than I do but my CC has two water heater switches on the front panel. I also have a set of 120 volt breakers in the bed room area. In addition, I HAVE TWO BREAKERS IN THE THIRD PASSENGER SIDE BAY. One of those breakers controls the entire drivers side of the coach's 120 volt input. Often, if one of these breaks, the 120 V side does not function. This is on the side where the heaters are located. ... this has to be a breaker problem... but what do I know?
Trying to help.
Pres

[Gil_J]

Bob,

Can you confirm you have a Aqua Hot and not a Webastco diesel heater and two electric hot water heaters. Please disregard if you have your answer.

Pres,

Those two breaker panels in your 3rd passenger side bay are for items powered by or through your two inverters. The hot water heaters aren't wired through the inverters. They are powered through dedicated breakers in the main AC panel in your bedroom you mentioned.

[Reagan Sirmons]

Gil,
Like I said... I know enough to be dangerous.
I have a question of you...how, then, do the hot water heaters function when driving down the road without the generator being on? Isn't the hot water generated due to the engine's heating of the coils within the heaters? I am under the distinct impression that the flow will not take place and thus the heating will not take place unless the switches are turned on allowing the flow of the heated engine coolant through the heaters?
I think I have it right?
Pres

[Gil_J]

Pres,

As long as the coolant loop valves are open your engine will heat the water in the 2 hot water tanks. With that said, you have 12V electric solenoids that shut off or turn on to limit engine coolant flow into the HW heaters when the water in the HW heater reaches 140 degrees. I have never traced the logic or power for these solenoids. It looks like there is something more I need to investigate.

[bigcitybob]

I wanted to give everyone an update on the hot water issue. I still have not been able to fix the hot water heaters. They are Atwood units and I am getting power to the unit, then it goes into the thermostat but not out to the heating element. They have reset buttons on them but they have not blown. Not sure what my next step is but I want to figure out how to fix them on my own if possible. I can't believe both units failed at the same time. I know I have to be missing something, not sure what it is.

Through all of this I learned about Webasto system on the coach, it was not working either. I had to take out the tool box unit located on the passenger side rear bay. Once I got to the Webasto I saw there was a wire that had come disconnected from the unit. I hooked it back up and then tested the unit and it fired up and worked perfect. So I now at least have hot water from two sources, the engine and the Webasto.

If anyone has any suggestions, let me know. Thanks again for the help.

BB

[JIM KELLER]

Big Bob, On the front of the Atwood heaters there are small round overheat protection devices that are common failures. I think two on each unit. Test to be sure you have current past those units. Gil will probably chime in on this post since he recently worked on the same issue.

[Gil_J]

Bob, it sounds like you have found the problem. If AC power is making it to one side of the thermostatic disk and not the other, it's the problem. I doubt they both went at the same time. When you get them replaced I bet you discover you have more hot water and it's hotter. One of them probably went long ago.

Before ordering new thermostats, check the high temperature resets and heating elements. Both are easily tested with an ohm meter across their terminals. The reset should read 0 ohms and both elements should read some resistance. As long as nothing reads an open, it should be good.

You do have hot water when you run the Web as to, don't you.

[bigcitybob]

Update: I replaced the thermostats and heating elements in both units and they are working fine. I had a solenoid valve that was leaking and slowly it was draining all the water from the tanks and that caused the problem. I corrected that first and then put the new parts in the hot water heaters and now everything is working. I am encourage by all the support and very grateful for when it is needed.

Have an awesome week,

BigCityBob