Question OASIS Hydronic heating underperforming with electric elements?

[turbopilot]

When I go to Newmar in September I'm having the heater fluid purged and replaced which I'm guessing is something most are not doing but it is in the service schedule. I'll let you all know if this alone improves the situation. I'm guessing if the coolant system is not performing as it should you're not going to have proper heat transfer. The only other suspect is the electric burners have a lifetime and need to be replaced.

OR, given some of the posts I have seen with fried electrical connections in the Oasis unit, what if there is a progressive deterioration in the quality of the electrical connections to these Oasis electrodes leading to heating of the wire instead of heating the boiler elements. All this leading to the wiring electrical fires we have seen posted on this forum. Whether you are heating the wires or the elements both would still show a high amp draw. I think we have a connector problem growing.

 

[Neal]

OR, given some of the posts I have seen with fried electrical connections in the Oasis unit, what if there is a progressive deterioration in the quality of the electrical connections to these Oasis electrodes leading to heating of the wire instead of heating the boiler elements. All this leading to the wiring electrical fires we have seen posted on this forum. Whether you are heating the wires or the elements both would still show a high amp draw. I think we have a connector problem growing.

If you haven't pulled the front panel off and traced the wires to the electric elements, I welcome you to do so and let me know your opinion. I've been in there far too much and the wire gauge is concerning and the type on top of that. The transition from the romex coming in the top and then the path to the electric elements are very odd, to me.

 

[turbopilot]

If you haven't pulled the front panel off and traced the wires to the electric elements, I welcome you to do so and let me know your opinion. I've been in there far too much and the wire gauge is concerning and the type on top of that. The transition from the romex coming in the top and then the path to the electric elements are very odd, to me.

Sounds like we know the answer. I have not pulled the panel. On my list. How long are the leads? Can they be easily changed? Going to use the boiler until there is an answer.

 

[Neal]

Sounds like we know the answer. I have not pulled the panel. On my list. How long are the leads? Can they be easily changed?

Well, it worked fine in the past. Seems like things have changed which is why I wonder if replacing the heater fluid (anti-freeze) will have a better result.

The romex comes in and transitions to some other odd wire type (braided?) then goes to a relay. The relay then has a wire to the electric elements I'd guess are 12-18 inches long. I'm guessing that wire is 12 awg (this is 120V and 20A I think?). I'm more comfortable with the wires from the relay to the electric element than I am from the romex to the relay. I recently replaced a relay as the spade separated from the bottom. Cheap chinese crap.

 

[turbopilot]

Well, it worked fine in the past. Seems like things have changed which is why I wonder if replacing the heater fluid (anti-freeze) will have a better result.

The romex comes in and transitions to some other odd wire type (braided?) then goes to a relay. The relay then has a wire to the electric elements I'd guess are 12-18 inches long. I'm guessing that wire is 12 awg (this is 120V and 20A I think?). I'm more comfortable with the wires from the relay to the electric element than I am from the romex to the relay. I recently replaced a relay as the spade separated from the bottom. Cheap chinese crap.

Are these wires documented with images (before they burn up) in some post?

 

[Neal]

Are these wires documented with images (before they burn up) in some post?

I'm not aware of one but ITR is good, you can call them (fastest) and ask them to email it to you. Good customer support and responsive by phone. 800-993-4402

 

[Neal]

ITR Oasis Service & Troubleshooting Manual

ITR Oasis Service & Troubleshooting Manual

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ITR Oasis CH-50 Manual

Oasis CH-50 Owner's Manual

rvforums.com

 

[redbaron]

Glycol based heat transfer fluids (aka: boiler fluid) do deteriorate over time. I did a google search, and every result was a paywall, but the cache data suggested 3-5 years was the typical useful life.

 

[turbopilot]

Glycol based heat transfer fluids (aka: boiler fluid) do deteriorate over time. I did a google search, and every result was a paywall, but the cache data suggested 3-5 years was the typical useful life.

I have not seen any change in operation using the boiler for hot water and heat, just hot water using only one AC circuit. When the coach was new during normal summer months one AC circuit on would cover normal hot water usage. Now it does not. May argue against glycol fluid as the issue.

 

[Neal]

I agree, I thought the same as burner is fine. I just don't know if it's throwing 50K BTU's at the heat transfer fluid vs 5K/element is the cause.

 

[redbaron]

I have not seen any change in operation using the boiler for hot water and heat, just hot water using only one AC circuit. When the coach was new during normal summer months one AC circuit on would cover normal hot water usage. Now it does not. May argue against glycol fluid as the issue.

Yes, that would argue against boiler fluid.

Another test point would be amp draw. Pay attention to the AMP load before you turn on the burner, and then see how it changes with 1 burner then 2.

A shorted or bad heating element will be "open", and therefore amp load will not increase. Same will be true if the wire became disconnected (aka: burned up).

A properly running electric heating element will be 10-13 amps of usage. Test with 1 element, and then test with 2. Make sure each climb up in usage.

**BEFORE DOING THE FOLLOWING - TURN OF ALL AC & DC POWER TO THE COACH**
For more detailed testing, open the cover and expose the electrical ends of the heating elements. Disconnect both wires so there is no circuit to the heating element. Then with a multimeter test the resistance between the 2 connectors. Properly working should be in the range of 10-30 ohms.

 

[Neal]

Yep, have verified per this thread where I learned that I had one side out (probably for a long time). With both sides verified drawing amps (11'ish per side) I still had the concerns as posted but I was in Montana and maybe it was ground water temps. I need to verify again and continue to monitor this situation as I don't have confidence in the electric heating elements.

How To - Verify your ITR OASIS Two Electric Burners are working

In my other thread about AC Heat not working I had a short, a second electrical short in the wiring of my OASIS system. In verifying the wiring ITR Heat had me go to my EMS panel and then turn AC I on and check for an AMP change. I showed +12 AMPS. Then switch to AC I and II and you should see a...

rvforums.com

 

[turbopilot]

Yes, that would argue against boiler fluid.

Another test point would be amp draw. Pay attention to the AMP load before you turn on the burner, and then see how it changes with 1 burner then 2.

A shorted or bad heating element will be "open", and therefore amp load will not increase. Same will be true if the wire became disconnected (aka: burned up).

A properly running electric heating element will be 10-13 amps of usage. Test with 1 element, and then test with 2. Make sure each climb up in usage.

**BEFORE DOING THE FOLLOWING - TURN OF ALL AC & DC POWER TO THE COACH**
For more detailed testing, open the cover and expose the electrical ends of the heating elements. Disconnect both wires so there is no circuit to the heating element. Then with a multimeter test the resistance between the 2 connectors. Properly working should be in the range of 10-30 ohms.

I have not opened the cover yet but did check the amp draw previously. Both elements are drawing the same amps as they did when new. Time to pull the cover.

 

[Neal]

I'm going with @redbaron's theory of ground water temp. No issues where I am for a hot shower on electric heating elements.