Engine antifreeze underneath Atwood H2O heater

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Engine antifreeze underneath Atwood H2O heater

June 22, 2019, 12:00:02 am

Hi,
We recently replaced the Atwood 10g water heater, (OEM came with engine assist heating of the water). One of the engine coolant supply lines at rear of Atwood was not tightened sufficiently. A slow leak. Engine antifreeze makes a messy utility bay after 4 hours driving in the mountains of Oregon. My mistake was not testing the install ourselves before driving anywhere. Would have been so easy to warm up engine to operating temp and periodically check for leaks at the Atwood. Oh well, this month begins our third year of coach ownership. We forgot the prime motor coach directive, check everything for ourselves, trust but verify.

We found antifreeze thinly puddled from the passenger to drivers side of coach. Most of it ran under the fresh water tank to drivers side of coach where the hose reels are. We have mopped up as much as we could reach and attempted to gravity drain some from under the fresh tank by tipping coach sideways. Can't really get it all because the fresh water tank sits on the bottom of this bay.

Any suggestions on what can be done to remove the antifreeze out of the utility bay? Should I even be concerned with leaving some antifreeze in the bay? I'm assuming that antifreeze won't degrade any of the components it has contacted. Plastic, foam insulation, fiberglass, silicone etc.

Thanks, Michael

Re: Engine antifreeze underneath Atwood H2O heater

Reply #1 – June 22, 2019, 01:38:14 am

Assuming a standard worm-gear screw clamp was used, a long arm and a nut driver should be able to tighten it a bit. The motoraide tube is aluminum and it might be possible to overdo tightening it, but a little bit goes a long way. Anti freeze is slippery stuff! As the motor aide tube is welded near the bottom at the back of the tank, assuming the clamps were positioned properly, they should be reachable for somebody who is somewhat limber and has long arms. I recently pulled my water heater out to fix the leak, but I also needed to replace the sensor strips on the fresh tank, so it was a buy one get one free sort of thing

I replaced the clamps with some beefier clamps that were wider. The hex heads of the clamps in those sizes are usually 5/16" but I have seen ¼" as well. Using a screw driver in that situation is a recipe for frustration. Since I had installed to ball vales on the motoraide loop, I was able to isolate the system and stop the leak until I was able to address the leak. Having only one valve on the loop (as it comes from the factory) shuts down the flow, increasing the dash heat capacity, but the other side of the loop is still pressurized.
Don

Quote from: Mike J – June 22, 2019, 12:00:02 am

Hi,
We recently replaced the Atwood 10g water heater, (OEM came with engine assist heating of the water). One of the engine coolant supply lines at rear of Atwood was not tightened sufficiently. A slow leak. Engine antifreeze makes a messy utility bay after 4 hours driving in the mountains of Oregon. My mistake was not testing the install ourselves before driving anywhere. Would have been so easy to warm up engine to operating temp and periodically check for leaks at the Atwood. Oh well, this month begins our third year of coach ownership. We forgot the prime motor coach directive, check everything for ourselves, trust but verify.

We found antifreeze thinly puddled from the passenger to drivers side of coach. Most of it ran under the fresh water tank to drivers side of coach where the hose reels are. We have mopped up as much as we could reach and attempted to gravity drain some from under the fresh tank by tipping coach sideways. Can't really get it all because the fresh water tank sits on the bottom of this bay.

Any suggestions on what can be done to remove the antifreeze out of the utility bay? Should I even be concerned with leaving some antifreeze in the bay? I'm assuming that antifreeze won't degrade any of the components it has contacted. Plastic, foam insulation, fiberglass, silicone etc.

Thanks, Michael

Re: Engine antifreeze underneath Atwood H2O heater

Reply #2 – June 22, 2019, 09:41:57 am

The first few years we had our coach, we had recurrent small intermittent leaks from the same 2 fittings on our OEM water heater. Usually happened in cold weather, and was never more than a small puddle directly under the heater. I tried tightening the hose clamps, but that didn't quite stop the leaks. Working space is tight behind the heater, but I finally managed to add a second hose clamp to each hose connection. That did the trick - no leaks since.

As to cleaning up the anti-freeze, short of removing the fresh water tank, I only see two options. One is what you have already done - wipe up as much as you can reach and ignore the rest. The other possible remedy would be to tilt the coach way over to one side or the other, and run some fresh water from a hose across the bay, flushing out the area under the water tank. Hopefully, all of the anti-freeze and most of the water would run out the low side of the bay. Then you would have to get the bay as dry as possible to prevent damage from the water. Perhaps leave both bay doors open and ventilate with a powerful fan?

I don't know what I would do. Anti-freeze is nasty stuff. It is sticky, it smells unpleasant, and it is usually a vivid color that will continually remind you of it's presence. Likely won't hurt the water tank material, but I don't know if it would have any long term harmful effect on the bay floor.

Tough choice.

Re: Engine antifreeze underneath Atwood H2O heater

Reply #3 – June 22, 2019, 11:03:42 am

Park on a slope side to side. That will allow more of the coolant to flow to the low side where you can remove more of it.

Pay particular attention to the seams at front and back of the compartment, as liquid there can get into the basement structure/rear bulkhead.

Re: Engine antifreeze underneath Atwood H2O heater

Reply #4 – June 22, 2019, 11:30:40 am

As far as removing the already present coolant, no easy way comes to mind. But... based on my experience of removing the tank for my bulkhead repair, it may be possible to drain the tank completely (as far as is practicable) and use wedges to carefully lift it up slightly to create a little bit of clearance underneath. I am talking about a quarter to maybe half an inch. Don't use wedges that are designed to snap off when inserted! The street side is the easiest to access if there are no reels, but it might be possible to carefully use a pry bar to accomplish this from the other WH side. I am speculating here, and it presupposes that someone with good common sense and a healthy fear of possibly causing unintended consequences therefore a willingness to abandon the plan in the event it appears to be too likely to cause collateral damage. At any rate, supposing it is possible to create a bit of air space under the tank, tilting the coach to the easiest to wipe clean side and using an air blow gun with a long nozzle from the opposite side, it might get most of the liquid to migrate to where you can wipe it up. I would NOT under any circumstances, attempt to flush it out with water. If there are any penetrations down there with failed caulking (likely), water will get in. Yes I am paranoid based on my experience after spending the first two years of coach ownership underneath grinding out rusty metal and welding in new steel etc. , but I feel I have earned the right to be paranoid!

Coolant, though undesirable where it doesn't belong, should not cause the steel framing underneath to rust. If you can get the bulk of it out from under the tank and maybe have a fan running on the high side after using the blow gun, it will dry and you won't have it reappearing every time you go down winding roads.
Just my thoughts on the subject...
Don

Re: Engine antifreeze underneath Atwood H2O heater

Reply #5 – June 22, 2019, 11:35:42 am

Any chance of throwing some kitty litter in there and vacuuming out with a crevice tool?

Re: Engine antifreeze underneath Atwood H2O heater

Reply #6 – June 22, 2019, 11:37:45 am

I bow to Don's 100% greater experience doing repairs in this critical area. Ignore my suggestion (above) to flush out the area with water.

Re: Engine antifreeze underneath Atwood H2O heater

Reply #7 – June 22, 2019, 12:37:19 pm

Don has had a terrible experience and is rightfully gun-shy. In summer, I would probably go against the grain and just wash the area out with the thought that unless you live in an area of constant high humidity, that it would quickly dry in warm weather, especially if driving. Every year about this time, I wash the carpet in the compartment and don't worry about it. I did have some rust and broken bolts in both bulkheads when we purchased the coach but that was a very long time ago and it's been fine since then.

With a coach that has lived in areas where the roads are treated with salt/chemicals, you do have to be especially cautious as the residuals when mixed with water can restart the corrosion process.

Pierce

Re: Engine antifreeze underneath Atwood H2O heater

Reply #8 – June 22, 2019, 12:49:40 pm

I respectfully disagree about adding water/rinsing the bay. It is not a matter of water evaporating from the FG floor of the wet bay-- agree, that will work unless in a humid area.

More (much more) it is that any water that gets down in the seams at front and back of the compartment gets into the sandwich of box beams and insulation where it can not evaporate.

Re: Engine antifreeze underneath Atwood H2O heater

Reply #9 – June 22, 2019, 12:56:01 pm

Is there anyway to get a shallow aluminum foil cake pan under the heater? If you can it will contain any smaller spills. I did this under the waste valves when I rebuilt them and added a third valve. It works!

Re: Engine antifreeze underneath Atwood H2O heater

Reply #10 – June 22, 2019, 01:05:32 pm

When I dumped about a gallon of antifreeze in
mine I took paper towels and stuffed them everywhere on both sides for about week. Left doors open, ran fans, and kept changing out the towels. It wicked up a lot over the week until towels were dry. I mistook my motor aid hose for fresh water overflow. Bad guess. I have no residual smell. I did put towels in every crazy spot I could reach.

Re: Engine antifreeze underneath Atwood H2O heater

Reply #11 – June 22, 2019, 01:42:42 pm

Thanks all.

I followed your basement bulkhead issue/rebuild closely Don. Scared the heck out of me so I too am adverse to any chance of contributing to problems down there. Going to tip coach over again today and see if any more seeps out. Didn't want to leave it tilted overnight under we have refrigerator empty and off. (No collateral damage please).

Brett, some antifreeze did seep into the basement joint at rear bulkhead in the outside corner of coach. Below that corner is where I saw a 2 inch spot on the pavement when we got home. A smaller spot appeared at the outside side of the next partition wall directly beneath water heater. See photo. I suspect at a minimum we spilled a cup to a quart max of fluid. Just enough to migrate across coach basement.

BTW: Our rear bulkhead bolts, and more importantly the joint shows no rust jacking. Clean connection, surface rust. However only a visual inspection has ever been done. No torgue test or sealant treatment. I don't know anybody here in Oregon to do this correctly. We will be traveling to Texas this fall, thought I'd get it checked then by somebody in the know. Any recommendations?

Re: Engine antifreeze underneath Atwood H2O heater

Reply #12 – June 22, 2019, 01:56:02 pm

Coolant is much less likely to cause rust issues than were you to flush with fresh water.

Coolant has rust inhibitors in it.

Re: Engine antifreeze underneath Atwood H2O heater

Reply #13 – June 23, 2019, 01:18:47 am

Thank you Brett,

Quote from: wolfe10 – June 22, 2019, 01:56:02 pm

Coolant is much less likely to cause rust issues than were you to flush with fresh water.

Coolant has rust inhibitors in it.

Good news those rust inhibitors! plus what I hope was a minimum of spill in bay. Weather here is mid 80's and very dry with constant breeze during the day. Keeping bay doors open and checking the paper towels for additional seepage/runoff. Hardly any visible today. Thinking of using an air compressor set at 30-40 psi to gently blow out compartment around the water tank bottom if we continue to see antifreeze.

Much appreciate everyones input. !!!

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Engine antifreeze underneath Atwood H2O heater

June 22, 2019, 12:00:02 am

Re: Engine antifreeze underneath Atwood H2O heater

Reply #1 – June 22, 2019, 01:38:14 am

Re: Engine antifreeze underneath Atwood H2O heater

Reply #2 – June 22, 2019, 09:41:57 am

Re: Engine antifreeze underneath Atwood H2O heater

Reply #3 – June 22, 2019, 11:03:42 am

Re: Engine antifreeze underneath Atwood H2O heater

Reply #4 – June 22, 2019, 11:30:40 am

Re: Engine antifreeze underneath Atwood H2O heater

Reply #5 – June 22, 2019, 11:35:42 am

Re: Engine antifreeze underneath Atwood H2O heater

Reply #6 – June 22, 2019, 11:37:45 am

Re: Engine antifreeze underneath Atwood H2O heater

Reply #7 – June 22, 2019, 12:37:19 pm

Re: Engine antifreeze underneath Atwood H2O heater

Reply #8 – June 22, 2019, 12:49:40 pm

Re: Engine antifreeze underneath Atwood H2O heater

Reply #9 – June 22, 2019, 12:56:01 pm

Re: Engine antifreeze underneath Atwood H2O heater

Reply #10 – June 22, 2019, 01:05:32 pm

Re: Engine antifreeze underneath Atwood H2O heater

Reply #11 – June 22, 2019, 01:42:42 pm

Re: Engine antifreeze underneath Atwood H2O heater

Reply #12 – June 22, 2019, 01:56:02 pm

Re: Engine antifreeze underneath Atwood H2O heater

Reply #13 – June 23, 2019, 01:18:47 am

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