Getting Hot under Kitchen Sink from Oasis

[dxg0001]

We usually leave the Oasis on AC 1 + 2 so we always have hot water. I never noticed this before but it is getting very hot underneath the sink area. As far as I can tell, the heat comes from the big hoses that go to the radiator.

I never noticed this before so I'm a bit worried something is wrong. I couldn't find anything in the manuals.

Anybody know if this is normal?

Thanks,
Dan

[Dutch Star Don]

Dan.....if you have the wall thermostat set to furnace, but turned down low, the Oasis system will continue to circulate coolant to the various registers in the coach, in anticipation of providing heat. If you are leaving the furnace on, at a low setting, try turning the furnace off until needed.

[Renipladlo]

Have wondered about this, pipe insulation would possibly help with this issue. On old coach, cabinet where register is, always gets hot, just bad air delivery system, short of a good PVC bender, no way to fix it great.

[lsodi]

Dan check to see if the summer switch on the oasis is turned on I had the same problem very hot under the sink. I called Newmar and they had me turn the switch off everything works great now

[Norm Mac]

You may have a stuck check valve. This is not as common as the other solutions listed, but it does occur.
If the problem continues after you have checked everything else, the stuck open check valve may be the issue.
The check valve usually opens when the circulating pump is running and the zone is calling for heat. Sometimes it gets stuck open and hot water will flow through the line without the pump assisting it. The natural flow will not heat the coach but it will warm the pipes enough to heat the lower kitchen cabinets.
The quick solution is to tap on the check valve with a hammer and it will usually un-stick itself, this solution maybe permanent or temporary.
There are several threads here providing more details.

[Algoma]

This is usually caused by the bypass switch being turned on. Check the top of your distribution module in the basement and make sure it is off.

[GKU]

I am having the same problem. Extremely hot under kitchen sink. AC 1 & 2 is on the furnace is off, burner is off, air condition is on.
Not sure that I fully understand the Summer Loop and how it is supposed to work. Can someone explain please???

[ptw]

Go in the compartment where the Oasis is and look for this silver box. There is a switch on the top of the box. Flip the switch and the pumps should turn off. If the pumps turn on the switch was in the proper position. That switch is used to fill the system as it turns on all the pumps. It is also used as a temporary solution to get hot water if the summer loop pump failed.

The summer loop pump sends heated fluid to the domestic hot water heat exchanger. When the furnace is on, the furnace loop pumps will also pump fluid to the domestic hot water heat exchanger. The summer loop pump will run as needed when the furnace is off. The summer loop pump is automatic and it is not necessary to do anything when seasons change.

[GKU]

Thanks Paul so it sounds like it’s best just to leave the summer loop ON. I will check that switch, and see if that solves my problem.

[ptw]

The summer loop pump is automatic. There is nothing you need to do.

The switch I mentioned, along with others in this thread, is called the bypass switch. The bypass switch should only be used for filling the system and as a temporary way to get hot water if the summer loop pump has failed. The bypass switch should be off.

[GKU]

So if this bypass is ON would that cause the Hot condition under the kitchen sink. Also if it is on it was like that since I got the coach this past September, would it do any damage?.

[ptw]

Yes, it would cause the hot condition.

No, on damage other than unnecessary wear on the pumps.

Here is a better picture. You can't see the switch, but is above the label on top.

If it is not the bypass switch then read Norm's post above.

[Algoma]

Originally Posted by GKU

So if this bypass is ON would that cause the Hot condition under the kitchen sink. Also if it is on it was like that since I got the coach this past September, would it do any damage?.

The bypass switch turns all the pumps ON regardless of the thermostat. Thus all your hoses will be hot, including the one under the sink. You will damage the pumps if this is left on. All coaches seem to be shipped from the factory with the bypass switch ON and the dealer should know to make sure this is turned OFF.

[GKU]

It appeared the switch was off. When I flipped it the other way the Heat Loop 1&2 lights came on, so I switched it back. I do not see the summer light on? In Paul’s photo the summer light is on.