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kharman · 01-02-2022, 04:51 PM

I ventured out in our 2015 Cornerstone to spend time with family in the Midwest. I'm not a fan of RV’ing to cold climates but away from them…but here we are. Last night we woke up to a 55 degree coach (outside temp in the teens)… I’ve taken care of our Aqua-hot, have a spare fuel nozzle, electrodes, and transfer fluid…I filled the empty reservoir and had heat for the rest of the night. Today I’ve been chasing down a transfer fluid leak and have found one. Exact location still unknown. It appears to be towards the front of coach but somewhere over the fuel tank—I assume the line heading to the floor exchanger or possibly the heated floor?

I’ve been tearing stuff apart all day and can’t get to it. Here is the question: I believe zone two is the floor heat and basement. So if it is the floor heat leaking I’ll need to live with it until I find the leak because shutting off heat in the basement would not be such a good idea. Zone 1 is the front of the coach and zone 3 the back—so if it is the line heading up to the front heat exchanger, possibly leaving zone 1 off might help on the leak?

If I’m backwards on any of this please jump in.

Has anyone been in this particular dilemma—I told my wife when we bought the coach new, that the floor heat sounded like a disaster waiting to happen…maybe that disaster has happened.

Kent and Jami

brobox · 01-02-2022, 05:02 PM

There is an elbow attached with clamps for the floor heat under the drivers seat accessed from the basement. That elbow was plugged with solids on my 14 not allowing the floor fluid to circulate. If your leak is in that area, it's a hidden place to look. My elbow was red in color.

kharman · 01-02-2022, 06:03 PM

Thank you very much--did you need to wiggle up from underneath near the front suspension?

brobox · 01-03-2022, 05:13 AM

Yes, Couldn't find a photo, but it was up in the drivers side front wheel well.

RVWheeler · 01-03-2022, 07:30 AM

I just watched a video from Entegra that explains the fluid flow if the Aquahot system. PJ indicted that zone 1&2 share the same loop. The difference is when the radiator fans are switched on and off for zone 1.
The point being, is that if you actual have a leak in the front of the coach, you have a leak in zone 1&2. It’s the same.
Here is a link to the video.
https://youtu.be/vLN11UNQKJs
Good luck and keep us posted.

757driver · 01-04-2022, 11:48 AM

Quote:

Originally Posted by kharman

Thank you very much--did you need to wiggle up from underneath near the front suspension?

That where I had a leak, where the red plastic line attached to the rubber hose. Poor quality hose clamps used. Location is in front of drivers side steer tire and way up high.

brobox · 01-04-2022, 02:32 PM

Quote:

Originally Posted by 757driver

That where I had a leak, where the red plastic line attached to the rubber hose. Poor quality hose clamps used. Location is in front of drivers side steer tire and way up high.

That the one that leaks and also get plugged with "less that perfect Aqua Hot fluid". Don is correct about the clamp quality.

kharman · 01-05-2022, 08:17 AM

Thank you Brobox, RVwheeler and 757Driver. The PJ video tutorial was great.

I found the location where the 90* elbow began the floor loop up under the drivers station. I wanted to confirm that the leak was in the floor. I traced the pump 1 circuit from the Aqua-hot, back through the holding tanks, over the the kitchen boost pump, then back towards the center of the coach (above the inverters) to make the trip to the front heat exchanger.

No leaks on the way forward...pulled the dash drawer and checked the front heat exchanger connections. Unfortunately, this all but confirmed that the leak was in the zone 2 floor loop.

I was able to abandon the floor loop by connecting a bypass run tied in just before the 90* elbow and ran it straight back to the Aqua-hot. Found a good straight path / route for the bypass line.

I capped the floor loop at the 90* elbow thinking I'll someday figure out how to fix the leak...and 2) it was not intuitive in figuring out the return end of the floor loop. I've asked Entegra for some better Aqua-hot plumbing diagrams. The 2018 general schematics did not provide much need information but eluded to a branch loop (possibly mid-bath)

There is more to do, but we had heat last night. This morning the overflow reservoir still had boiler fluid so the leak may have been confirmed.

This is our fourth coach and the longest we ever kept one--maybe it is time to trade.

RVWheeler · 01-06-2022, 03:43 AM

Kent,
Great job troubleshooting this issue. Also love your work around solution.
Now I was thinking you could connect an air source, valve and a gauge to the isolated floor section, cap the other end and pressure test the under floor Pex and leak check it with air. You can also use the air to remove the boiler fluid that remains.
I’m surprised you didn’t see any evidence of boiler fluid leaking from the floor structure. Don’t give up yet. Sounds like you have the skills to take this a bit further.
Keep us posted.
Bob

kharman · 01-16-2022, 04:03 PM

Entegra Technical Support was very helpful in providing schematics--but they were initially hesitant. Their initial response was "we can't provide support on modifications".

I suggested we reframe the conversation as "troubleshooting"...and that worked.

What you will not see on the schematics is the floor loop comes back down to the basement just above the Aqua-hot with another 90 degree heater hose bend. From there the floor loop heads to the rear bath then returns to the Aqua-hot.

This was good news because it allowed us to by-pass the main cabin portion of the floor loop but still keep the rear bath floor heat operational. But not the bedroom floor.

I did use a wetdry vac to empty the main cabin floor loop then capped both ends in case someone ever wanted to revisit this project...will not be me.

If anyone experiences a similar issue don't hesitate reaching out.