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wildcat30 · 03-21-2025, 06:26 PM

1-min of hot water then none. Oasis Chinook, the coach is less than 1 year old. Called Newmar and got on a conference call with ITR to troubleshoot a week ago. ITR via Newmar sent me a new controller board (the smaller silver box that flashes red when normal). I replaced it and still have the same issue.

Using Oasis Burner or/and electrical AC1/2 elements, I get one heat cycle for hot water. Use the sink, shower, and after a minute or so, cold water. The burner does not turn back on and AC1/2 show "Enabled" instead of "On" when there should be demand for them to turn back on.

Using the Oasis for heat works as it should. The burner turns off and on as needed, and plenty of heat is out of all zones/registers.

Of course, it is Friday after I just replaced the control board and discovered that it is not the problem. Maybe a water temp sensor in the Oasis? I will call Newmar/ITR back on Monday but thought smarter people here might have some insight.

FledCali · 03-21-2025, 06:59 PM

Quote:

Originally Posted by wildcat30

1-min of hot water then none. Oasis Chinook, the coach is less than 1 year old. Called Newmar and got on a conference call with ITR to troubleshoot a week ago. ITR via Newmar sent me a new controller board (the smaller silver box that flashes red when normal). I replaced it and still have the same issue.

Using Oasis Burner or/and electrical AC1/2 elements, I get one heat cycle for hot water. Use the sink, shower, and after a minute or so, cold water. The burner does not turn back on and AC1/2 show "Enabled" instead of "On" when there should be demand for them to turn back on.

Using the Oasis for heat works as it should. The burner turns off and on as needed, and plenty of heat is out of all zones/registers.

Of course, it is Friday after I just replaced the control board and discovered that it is not the problem. Maybe a water temp sensor in the Oasis? I will call Newmar/ITR back on Monday but thought smarter people here might have some insight.

Might be a bad summer loop pump? If you toggle the switch on the top of the silver box do you get consistent hot water?

wildcat30 · 03-21-2025, 07:38 PM

I tried that a few weeks ago and no difference but I’ll try it again. Good suggestion. Thanks

NCC-1701A · 03-22-2025, 08:17 PM

If it was a bad summer loop, I don't think you'd get hot water at all as it wouldn't pump any hot boiler fluid through the heating coils. And if you've tried your bypass switch that would pump hot fluid and you'd get hot water. So, my first thought was the water temp sensor as well.

Since you are getting heat to your registers, the boiler and the zone pumps are working.

I assume you've checked all the lights in the board silver box since you replaced the board and all looks OK there?

Another far fetched idea would be that the impeller in the summer loop pump "locks up" when heated, but that's pretty far out. I have had impellers stop, but it always took a few raps on the pump with a screwdriver handle to get them moving again. They never "self started" again. Also, you've tried the bypass, so not that.

I can't think of what else would be wrong or make the system think you have hot water other than the water temp sensor telling the system your water is hot.

wildcat30 · 03-22-2025, 08:51 PM

Thanks NCC-1701A, that sounds the most logical, bad temp sensor. During troubleshooting with ITR only green lights on the control board, and hoses were hot except for the domestic (red) pex line that feeds the hot water run of fixtures in the coach. So the more I think about it, the more it sounds like a thermostat/temp sensor in the Oasis.

mahdi · 03-22-2025, 08:54 PM

I have had the same problem. I took it to NIRVC in Phoenix and they changed the control board. Still same issue. I took it to ITR and they changed the summer pump. Have not tested it yet but the heating works well from all registers. ITR said even though not fault red light on the summer pump the impeller could be broken.

wildcat30 · 03-22-2025, 09:00 PM

Mahdi, I would be curious to know once you get a chance to try it if that fixed your problem. Tomorrow I plan to try mine once again after a reset and in bypass mode.

NCC-1701A · 03-22-2025, 09:02 PM

Mahdi: he tried the bypass switch, which would turn on the zone pumps and give hot water in the event of a summer loop failure. That didn't fix the issue. That would suggest the system thinks there is hot water, at least in my mind. If a board isn't the fix, I'm not sure what else is preventing water flow through the oasis other than the temp sensor. ???

mahdi · 03-23-2025, 09:04 AM

Firstly, the hot water is working fine in my case. I have run it for 2 days. When I went to ITR, the NIRVC tech had thought it was the temperature sensor. However they said that was fine and changed the summer loop pump as stated. Now it is working. Before that when I ran the bypass the hot water function was intermittent.
I hope this helps.

wildcat30 · 03-23-2025, 01:16 PM

Thanks for the update Mahdi, glad yours is working!

Today:

1. Turned on Oasis burner with AC1 which had been "Enabled" but have yet to see it switch to blue "ON" to indicate AC1 is heating.

2. Burner does not turn on after waiting 5 minutes.

3. Turned on the bypass switch on top of the lighted zone board in the Oasis compartment.

4. No burner yet even though on Silverleaf it says Burner "ON".

5. I then activated two zones of Oasis heat. The burner comes on and I get heat from the two-zone registers.

6. Turn on the shower, and have warm water for less than 20 seconds.

7. Turn on the sink to hot water and shower to full hot water and no hot water from either source. Oasis bypass is still activated as indicated by green lights on the Oasis panel in the compartment.

This leads me to believe that it is the water temp sensor?

NCC-1701A · 03-23-2025, 04:19 PM

Quote:

Originally Posted by mahdi

...Before that when I ran the bypass the hot water function was intermittent.

That's really interesting. Everything I've ever heard and experienced myself, if the summer loop pump is out, is that the bypass running the zone pumps continuously will ensure hot water. Never heard of it only working intermittently.

Everytime I think I have these systems mostly figured out, I learn something new. :-)

wildcat30 · 03-24-2025, 10:55 AM

First, thanks for the replies and help!

After troubleshooting with ITR they now determined it is the summer loop pump.

One troubleshooting step that I have not come across before (I am sure it is here somewhere on IRV2), but thought I would share it just in case it will help someone else.

1. Remove front cover, all screws (the screws not on the perimeter just hold the control panel onto the cover, you'll have better access to just remove them along with the perimeter screws)

2. On my Chinook, the summer loop pump is in the bottom left corner. The other two pumps are above and on the right. You can double-check by the routing of the hoses attached to the pump.

3. Open a hot water source (kitchen sink for example and let it flow)

4. find the red and black power wires to the summer loop pump and unplug the black/ground connector for 10 seconds.

5. reconnect the black wire, my pump ran for a short time then started turning off and on with a different sound compared to when it is running. This could be cavitation or just the motor stalling/starting. This is the indication of a bad motor that will intermittently work.