Aqua Hot Pump Upgrade and Drain/Flush

[hogdriver]

I have been saving (dreading) an Aqua Hot makeover until I could make some time between work and trips and my warranty expired. A few months ago my stir pump failed. DW complained of lukewarm showers and red pump light on AH control panel in basement. I called Entegra and they generously sent me a pump a few months after my warranty expired if I would handle the labor cost. I took my time and conversed with a few forum members about how to drain and flush the AH coolant. Without flooding the deceased horses I was one of the original posters about brown AH coolant with Brobox and sent my coolant in for analysis. I found Camco pink boiler fluid on the Interweb for about $10/gal, which is about 1/2 to 1/3 the price of the Century green Fluid. After the way my fluid discolored from the factory build I determined to use the Camco. I ordered 12 Gals ( which is just about perfect). The next thing I did was figured if I was going to drain everything why not upgrade the pumps to the Buehler pumps. Entegra replaced all my original round 105 pumps last year (18 mos ago really)as part of the AH recall. I had the square 108 pumps and my first one failed 18 dos later and I only use the RV part time. Not good. I ordered two upgraded Buehler pumps from Roger Berke to match the one Entegra provided.

Then I gathered supplies which included; three new pumps, 12 gals Camco boiler fluid, three 5 gal buckets, an old RV water pump affixed to a board, 30 gals of distilled water (yes, I bought 20 gals first and was not enough it took 30).

The problem with this whole procedure is I would not suggest doing this in a campground unless broken down. You have to be able to handle a lot of fluid and water. My RV storage guy graciously allowed me to work at his place. The hardest problem is what to do with all the drained coolant. About 40 gals of nasty. In my case the local municipality said less than 250 gals of propylene glycol can be disposed down the waste drains. Some cities require it to be taken to recycling. In reality you have 10-12 gals of 50/50 propylene glycol and 20-30 gals of flushing water with low concentrations of glycol but unknown contaminants. I chose to do the work myself as I wanted to learn my AH system better and it would be real expensive to pay an RV guy to do this as it took an entire day and part of another.

First replace the pumps. The stir pump is the worst (right pump) as you have to remove the burner to get it in and out. This also requires clamping and disconnecting fuel lines.

Then drain the old coolant. You can see in the first picture the fluid is dark green with brown and black sediment.

The next step was flushing. I used distilled water connected via temporary plastic tubing into the Zone 1 origin above pump 1 then later on Zone 2 above pump 2. I drained via the AH drain line until each zone ran clear. Zone 1 (front) was more dirty than zone 2. I then used a compressor and expelled all the water with the sediments I could get out of each zone. I was glad I did. The compressed air blew the last of the distilled water with really brown and nasty fluid.

I reconnected the lines and started pumping new pink fluid from the drain into the AH as per the manual for refilling the system. It took about 6 gals and then came out from the overflow. I then jumped all the circulation pumps by attaching their blue wires to ground and was able to add about 3 gals more after burping the system.
Then I buttoned the system up and fired it up. I got the system hot and it ran for a bit until the AH shutdown for LOW FLUID CUTOFF. I wasn't surprised. The system had expelled more air. I added about 2 gals more until full. Overall I had put in 11 gals into a system reported to hold 12, so I know my concentration is a little off with remaining water in the lines.

I'm happy to report I am now pretty in pink.

[brobox]

Excellent post Dave. Sorry to say your post brings back very not fond memories.
Darin, the AH tech that did my flush and motor change told someone this year he would no longer do flushes, way to time consuming. It was 7 or 9 hours to complete mine with the blockage it had. I am guessing AH would not pay him enough for the time he spent.

[Matt D]

Dave, excellent write up.

Thank you for taking the time to compose that great tutorial.

We have the 400D, not the 450D and I wonder if these pumps are the same? I will contact Roger to see.

-Matt

[photopilot]

Aren't you lucky to have your Aqua-Hot accessible that easily! To get to mine, I have to crawl in the next bay and work through sliding doors! Glad you were successful. Not having any service records on our new to us coach, I went to flush it and the first fluid came out the same color pink as the new fluid. I stopped there!

Walt

[voltdoc]

Originally Posted by Matt D

Dave, excellent write up.

Thank you for taking the time to compose that great tutorial.

We have the 400D, not the 450D and I wonder if these pumps are the same? I will contact Roger to see.

-Matt

Dave, great write-up, thanks for sharing!

Matt, 400D only has two pumps. No stir pump. On mine they are round and branded Cooper Standard.

Link to photo:
https://goo.gl/photos/z74PnmUhdow2izie9

[Cruzer]

Nice post, Dave. That mirrors pretty much what I went through when replacing my pumps with the new style except I'm still using the green stuff. The jury is still out on that.

[lowejug]

Originally Posted by photopilot

Aren't you lucky to have your Aqua-Hot accessible that easily! To get to mine, I have to crawl in the next bay and work through sliding doors! Glad you were successful. Not having any service records on our new to us coach, I went to flush it and the first fluid came out the same color pink as the new fluid. I stopped there!

Walt

Your Aqua hot is the original build era back when they built them right and Aqua hot were flawless.. my Monaco dynasty had the same,
These new ones are not half the units ias the old
This post proves that. Pages of of Aqua hot problems on this site

[hawgguy]

Excellent - thank you. I have done the same myself using similar technique.

Did you activate the pump for the floor loop located on the other side of the bus? I neglect this.

[RubiconTrail]

Nice post Dave. Filing this one.

Lowejug, I think you are right. This not just an Entegra problem. Same pages of problems on other owner forums. For as much as an AH unit costs you'd think it would be flawless. Room in the market for a less expensive and higher QC product?

[hogdriver]

Yep, sure did Bob. After reading your post last year I really wanted the Zone 1&2 loops flushed. I rigged a couple old spools of wire to each pump all grounded to the front DC lugs in the front left compartment.

I think if I had to do this again I'd do either like your posting and run plain old tap water (assuming it's not dreadful with minerals) and flush each loop like 15-30 mins. Then flush again with distilled water to purify the lines. This way it would use a lot less distilled water.

Or, I'd just buy like 50 gals of distilled water. They were about $.88 at Walmart. Then flush until clear, use air to purge, then flush again then purge again.

There was a lot of sediment in my system. I'm not a chemist, but I am a Mechanical Engineer and I've never seen a boiler system with that much junk in it. Without opening myself to some lawsuit I can only speculate that the boiler, tank, heating coils or some other part is coated with something that heating breaks down. My theory is the Century green fluid either does not have a decent corrosive inhibitor or some vendor changed the way the make one of the components (say the pump or the Chinese company making the AH boiler) and didn't check compatibility. I'm hoping the first 2-1/2 years of running the green stuff has loosened whatever it is and by flushing and running the Camco pink my system will now run a long time. It certainly can't be any worse than the green fluid and is lot cheaper and easier to obtain.

[Gary.Jones]

Dave:

Really nice write up and complete with pix.... You da MAN!! As you may remember, I did the same and paid for two Buehler pumps myself and then Entegra paid to install them along with one "108" pump that had failed again this time and the "108" which was replaced by a Buehler , so I bit the bullet and now have all 4 pumps upgraded to Buehlers, and I pray that this means that I never have problems again. Unless I misunderstood what you did, I think you must still have one "105" or "108" pump still in your system (the engine heat loop) since I think you replaced only 3 pumps and not all 4. I am assuming that you feel the engine heat loop is used so infrequently that it was not worth replacing it..... I agree with that assessment (living in the south and trying to avoid cold temps as much as possible), but I replaced all four of my pumps.

Thanks again for the nice write up..... although I am hoping that I never again need to service AH pumps, this thread goes into the "Important threads Archive" and will be with me as long as I own this coach.

Gary

[hogdriver]

You are exactly correct Gary. I left the remaking 108 square pump on the back of the AH for the Engine Preheat because I have only used it about twice. It is also circulating the Engine coolant vs the AH coolant and I think it is not getting as many contaminants as the AH loops. At least it is still pink (I have Cummins Compleat ES coolant from a previous adventure vs the red Final Charge) vs the brown color that came out of the green fluid loop. I also saved the two operable 108 pumps as "roadie spares or giveaways" so I have two replacements available.

[757driver]

Dave,

Excellent post, thanks for the information.

[BeHappy]

Dave - great write up, photos appreciated!

Love our Entegra, but AQH mfr pump quality issues gives me pause

Safe Travels to All


2015 "Classic" Cornerstone