Excessive Heat Kitchen Area Under Sink

[hugh37]

Should've resolved this before now...however, even at this moment, RVing in the South Florida area, the temperature behind the draws and doors under my kitchen sink, the temperature is high 90's to over 130 degrees. Naturally, that temperature is affecting at least the living area of the coach...when I'm needing cooler temps. For some time I've been leaving the Oasis electric ON for hot water. Is that the problem...and should I NOT leave it ON? Larry

[Old-Biscuit]

Is the Oasis located in that area?


IS it missing/lacking insulation in that area?


Should NOT be an issue leaving Oasis ON 24/7.


You need to investigate in/around Oasis for source of heat.....where it shouldn't be!

[Ricci]

Hi Hugh37 - It sounds like you have the "summer loop" bypass switch on. That will cause the other two pumps to run constantly and circulate hot water through the heat exchangers (the fans don't run unless the thermostats call for it). If you go to the Oasis the odds are that you will hear those two pumps running constantly as a clue to the issue. Solution is to turn the bypass switch off. The switch is there for diagnostic purposes and as a back up in case of a bad summer pump so that you will have domestic hot water.


Tom

[Norm Mac]

Hugh; Many of us have had this same problem.
As others have said; First check the Summer Loop switch and check if pumps are running. Once you have determined that the summer loop switch is correct and the pumps are not running you can likely move on to the very likely problem.

The zone valve is stuck open and hot water is flowing through zone 1 even with the pumps off. The good news is this is easily fixed with a few taps of a hammer. The bad news is you need to get to the distribution unit which is on the backside of the Oasis.
There are a few threads here on iRV2 with the exact step by step instructions.
We had this exact same problem, heat buildup under the sink and under the pull out countertop/drawer unit. With a few taps, the valve became unstuck and we have had no further problems. We were told by Oasis that if the problem persisted we would need to eventually replace the valve unit itself.

[hugh37]

Thanks, fellows! Should've made known that I DO have my BYPASS switch ON, because my Summer Loop Pump (SLP) is bad and I'm awaiting my replacement, any day. Sounds like having the bypass switch ON does create more heat in my "problem" area; however, until the past few days I've kept that switch OFF and still experienced what I considered way too much heat. Question: should the area in question be considerably hotter than outside, in the living area under NORMAL circumstances?? Many thanks for your help, Larry

[Ricci]

Hi Larry - Glad to see that at least some of your issue is abated. Whether the area under the countertop and drawer area should be warmer really depends on a lot of factors. If the sun is on that side it may be warmer. Also the AC (if it's on) doesn't get to that area directly so any heat from outdoors or the sun will make it warmer. Norm Mac made a point about the check valves but they usually stick closed rather than open. BTW -Keeping the electric element on all the time will not cause any issues, just remember to turn them off before unplugging from shore power as the load might cause the points on the transfer switch to arc and pit over time.

Good luck with the new summer pump. Lots have fallen by the wayside.


Tom

[hugh37]

Thanks for the "pointers", Tom. Expect my new summer loop pump to come tomorrow. While installing it I plan to "exercise" the mixing valve, as never have. Norm Mac...you mentioned the zone valve may be stuck open...I have no idea where it's located and what is looks like. Is it a check valve? Have done lots of searching, but can't find what you're referring to. Help, please. Thanks to all, Larry

[Ricci]

Larry - Don't want to step on Norm Mac's response but when you get into the distribution panel you will see the check valves. One is just above the summer pump (see attached picture). Same for each of the pumps.


Tom

[hugh37]

Thanks, Tom...great photo work! I accessed my Distribution Module a few days ago and left it open, ready for the new pump. Appreciate directing me to the check valves, too. Don't expect any problem installing the new pump. I'll be sure to check out the mixing valve, as there apparently have been problems caused by not "excercising" it. ?? Again, appreciate all the help. Larry

[bandcworkhorse]

Just changed the #1 loop pump on mine. (#2 pump last year) As others have said, getting the baked-on hoses off, (and back on) is a challenge in the tight confines. I'm adding a couple feet of 1/2 hose to my maint kit so I can cut and replace. And some quality worm clamps. Those spring clamps are beyond frustrating. Too bad these $300 pumps have such a poor MTBF.

[hugh37]

bandcworkhorse...thanks for the info and help. Really a bummer that so many pumps have "gone bad" so early. Thankfully, my new one being shipped is the "new" model, per ITR. I'm hoping for no big problem with the install. Should I need replacement hose my local NAPA has 1/2" heater hose by the foot. They may well have the quality worm clamps you mentioned if I need them. We'll see. Again, thanks! Larry

[lenny-shawna]

Originally Posted by Ricci

Hi Hugh37 - It sounds like you have the "summer loop" bypass switch on. That will cause the other two pumps to run constantly and circulate hot water through the heat exchangers (the fans don't run unless the thermostats call for it). If you go to the Oasis the odds are that you will hear those two pumps running constantly as a clue to the issue. Solution is to turn the bypass switch off. The switch is there for diagnostic purposes and as a back up in case of a bad summer pump so that you will have domestic hot water.


Tom

Hi Tom,
This is probable a stupid question but what is a "Summer Loop", is there and where would the switch be located?

[Ricci]

Hi Lenny - When you are not running the interior heat you still want to have domestic hot water (thus "summer pump"). The summer pump sends boiler fluid between the boiler and the heat exchanger in the distribution panel. That's how you continue to get domestic hot water in the summer. If that pump dies, the way around is to flip the summer pump bypass switch which causes the two circulator pumps to run continuously so that you can get domestic hot water. The down side is that you need to turn that switch off when you are not using hot water to save the pumps and to keep from having hot boiler fluid running all the time. While the fans don't come on inside the coach you will still get some heat from the heat exchangers.
The switch is located on the top of the panel that has all the status lights on it, usually behind or to the side of the boiler unit. Feel along the top and you'll spot it.

Hope that helps.
Tom

[lenny-shawna]

Originally Posted by Ricci

Hi Lenny - When you are not running the interior heat you still want to have domestic hot water (thus "summer pump"). The summer pump sends boiler fluid between the boiler and the heat exchanger in the distribution panel. That's how you continue to get domestic hot water in the summer. If that pump dies, the way around is to flip the summer pump bypass switch which causes the two circulator pumps to run continuously so that you can get domestic hot water. The down side is that you need to turn that switch off when you are not using hot water to save the pumps and to keep from having hot boiler fluid running all the time. While the fans don't come on inside the coach you will still get some heat from the heat exchangers.
The switch is located on the top of the panel that has all the status lights on it, usually behind or to the side of the boiler unit. Feel along the top and you'll spot it.

Hope that helps.
Tom

It does and thank you Tom