Water lines

[Hyatt]

Does this happen when your on city water or when your drawing from your fresh water tank, I had the same problem with mine when I was using my fresh water tank, Hot and Cold were switched.

[richguess]

My 2018 ACE 27.2 had the same problem, on on City water. The lines going under the floor were reversed. I had people tell me what I was describing was impossible. Not!!

If it’s BOTH city and tank water, recheck the valves. Fairly simple. I figured mine out by drawing a diagram.

[Jimbo56]

Am I blind or was the question ever answered as to the hot water tank bypass valve being left open by the dealer who unwinterized it?

[16ACE27]

Originally Posted by Jimbo56

Am I blind or was the question ever answered as to the hot water tank bypass valve being left open by the dealer who unwinterized it?

OP is leaving it up to the same dealer that couldn't fix it before to try to fix it again.

[dkoldman]

Originally Posted by Jimbo56

Am I blind or was the question ever answered as to the hot water tank bypass valve being left open by the dealer who unwinterized it?

Well have you considered that if the question is answered with full disclosure, how can they blame the Mfg? Point is the hot & cold water are backwards and the knee jerk gates are open for poor quality

Think about how many points of failure / misses would have had to occur if it was wired at the factory. No one I mean no one ever notice the hot water did not work.

[Jimbo56]

Originally Posted by dkoldman

Well have you considered that if the question is answered with full disclosure, how can they blame the Mfg? Point is the hot & cold water are backwards and the knee jerk gates are open for poor quality

Think about how many points of failure / misses would have had to occur if it was wired at the factory. No one I mean no one ever notice the hot water did not work.

How did we find out they’re backward?

[16ACE27]

Originally Posted by Jimbo56

How did we find out they’re backward?

We didn't. That's just one guess in this thread.

[Jimbo56]

Originally Posted by 16ACE27

We didn't. That's just one guess in this thread.

We’ll Ted, I hope someone decides to check the hot water tank bypass valve. Sure seems like a simple fix to me. But maybe we need 500 more guesses.

[dkoldman]

Originally Posted by Jimbo56

How did we find out they’re backward?

Not that the root cause was proven to be backwards plumbing, but the effective end result from the owner's perspective is the hot & cold water are backwards.

Bypass or plumbing, my money says it is something the dealer did or plumbed incorrectly while working on it?

[JimOIB]

Originally Posted by Jimbo56

We’ll Ted, I hope someone decides to check the hot water tank bypass valve. Sure seems like a simple fix to me. But maybe we need 500 more guesses.

Followed by the cold water inlet check valve. I would hope a competent RV tech would know how to dewinterize and set the bypass valves correctly - if not then look for a different shop. The check valve could have corroded over the winter and be stuck open.

[JimOIB]

Originally Posted by dkoldman

Well have you considered that if the question is answered with full disclosure, how can they blame the Mfg? Point is the hot & cold water are backwards and the knee jerk gates are open for poor quality

Think about how many points of failure / misses would have had to occur if it was wired at the factory. No one I mean no one ever notice the hot water did not work.

Originally Posted by dkoldman

Well have you considered that if the question is answered with full disclosure, how can they blame the Mfg? Point is the hot & cold water are backwards and the knee jerk gates are open for poor quality

Think about how many points of failure / misses would have had to occur if it was wired at the factory. No one I mean no one ever notice the hot water did not work.

I’m sure the OEM can miss stuff. My hot/cold was hooked up backwards as I mentioned above. OEM so kindly left the QA sheet in the coach for me. Item 4 - hot/cold orientation. In fact all of plumbing is unchecked. Clerical error or someone not on their game after the 3 day New Year weekend?

Attachment 37628

[dkoldman]

Originally Posted by jimbo12

I’m sure the OEM can miss stuff. My hot/cold was hooked up backwards as I mentioned above. OEM so kindly left the QA sheet in the coach for me. Item 4 - hot/cold orientation. In fact all of plumbing is unchecked. Clerical error or someone not on their game after the 3 day New Year weekend?

Attachment 37628

I don't think I was saying that OEM could not miss stuff. But let me play it out for what what I mean when I said how many points of failures /misses.

We assuming a plumbing backwards issue

1. Assembly work connect wrong and miss
2. QA for the line fail to catch
3. QA Final inspection for deliver miss (what you posted)
4. Dealer Inspection for Pickup delivery ( they may not check hot/cold water but they can check the sheet that you posted. Most cases they are winterized so plumbing checks may not exists)
5. Dealer Inspection upon receipt. ( they certainly should have seen that sheet) If winterized this will not occur.
6. Customer PDI

[Chateau_Nomad]

This CANNOT be that hard to diagnose the root cause! The source of the issue originates at the water heater. There's a (should be) blue cold line going IN, and a (should be) red line coming OUT. Then there's a bypass valve connecting the two (which should be OFF/CLOSED.

Make sure water tank is operational, connect to city water (or turn on pump), open both hot and cold faucets at sink.

Grab water lines at various points along their path... red should feel hot, blue should feel cold.

If both lines are warm, the bypass valve is open. Otherwise follow the hot/red and cold/blue plumbing until you find the offending pattern... all the way to all faucet connections under the sinks.

[Jimbo56]

Originally Posted by jimbo12

Followed by the cold water inlet check valve. I would hope a competent RV tech would know how to dewinterize and set the bypass valves correctly - if not then look for a different shop. The check valve could have corroded over the winter and be stuck open.

The word here is competent. Until the OP tells me it was checked, my money is on the bypass valve left open. And if that’s not the first thing to check I’ll shut up.

[JimOIB]

I took everything in this thread and summarized it in terms of failure modes and probability of occurrence. Might be overkill (insert “beating a dead horse” GIF here) but will help the OP before they go back to the shop.

There are at least 3 failure modes that could cause the OPs situation - 2 caused by human failure and one caused my mechanical failure. They can figure out the exact failure mode in less than 20 minutes.

Mode 1 - Human failure. Bypass valve left open. High probability. Verify by visual inspection. While at it make sure all the valves are in the correct position.

Mode 2 - Human failure. Hot and cold water plumbed backwards. Low probability unless the coach plumbing was recently worked on or a new coach. Verify at the kitchen faucet. Pressurize water system with city water port or pump, turn hot water heater on, drink a beer as the hot water heats up. Turn on cold water, if it still runs hot after 3-4 minutes then turn on hot water and see if it runs cold. If this is the case then Mode 2 failure.

Mode 3 - Mechanical error. Cold water inlet check valve stuck open. Low probability. Verify at the kitchen faucet. Pressurize water system with city water port or pump, turn hot water heater on, drink a beer as the hot water heats up. Turn on cold water, if it runs hot and after 3-4 minutes turns cold then turn on hot water and see if it runs hot. If this is the case then Mode 3 failure.

I think 3-4 minutes will be enough time to let the water pressure in the system bleed down to where the city water or pump check valve will open and control the pressure of the system. The heating of the water in the tank raises the pressure of the system a bit due to thermal expansion and will keep those 2 valves closed. A bad check valve has the same symptoms as an open bypass valve.

[JimOIB]

Originally Posted by dkoldman

I don't think I was saying that OEM could not miss stuff. But let me play it out for what what I mean when I said how many points of failures /misses.

We assuming a plumbing backwards issue

1. Assembly work connect wrong and miss
2. QA for the line fail to catch
3. QA Final inspection for deliver miss (what you posted)
4. Dealer Inspection for Pickup delivery ( they may not check hot/cold water but they can check the sheet that you posted. Most cases they are winterized so plumbing checks may not exists)
5. Dealer Inspection upon receipt. ( they certainly should have seen that sheet) If winterized this will not occur.
6. Customer PDI

Perfect. #6 - old hats would catch this but a newbie like me, not knowing what I was doing and not knowing about this forum and the fountain of knowledge, missed it. Result was a complete system failure. If only I knew then….

[dkoldman]

Originally Posted by jimbo12

I took everything in this thread and summarized it in terms of failure modes and probability of occurrence. Might be overkill (insert “beating a dead horse” GIF here) but will help the OP before they go back to the shop.

There are at least 3 failure modes that could cause the OPs situation - 2 caused by human failure and one caused my mechanical failure. They can figure out the exact failure mode in less than 20 minutes.

Mode 1 - Human failure. Bypass valve left open. High probability. Verify by visual inspection. While at it make sure all the valves are in the correct position.

Mode 2 - Human failure. Hot and cold water plumbed backwards. Low probability unless the coach plumbing was recently worked on or a new coach. Verify at the kitchen faucet. Pressurize water system with city water port or pump, turn hot water heater on, drink a beer as the hot water heats up. Turn on cold water, if it still runs hot after 3-4 minutes then turn on hot water and see if it runs cold. If this is the case then Mode 2 failure.

Mode 3 - Mechanical error. Cold water inlet check valve stuck open. Low probability. Verify at the kitchen faucet. Pressurize water system with city water port or pump, turn hot water heater on, drink a beer as the hot water heats up. Turn on cold water, if it runs hot and after 3-4 minutes turns cold then turn on hot water and see if it runs hot. If this is the case then Mode 3 failure.

I think 3-4 minutes will be enough time to let the water pressure in the system bleed down to where the city water or pump check valve will open and control the pressure of the system. The heating of the water in the tank raises the pressure of the system a bit due to thermal expansion and will keep those 2 valves closed. A bad check valve has the same symptoms as an open bypass valve.

This is great. I will add it to my personal cheat sheet that I call SOP. It was when I 1st joined the forum for me to learn what to do and no to do. As I have learned more; I don't use it as much. I also have found that a lot of things that I had added either did not apply to the coach I actually bought, or simply were not true. Nonetheless it gave me confidence to pull the trigger and boy did I get it right

[dkoldman]

Originally Posted by jimbo12

Perfect. #6 - old hats would catch this but a newbie like me, not knowing what I was doing and not knowing about this forum and the fountain of knowledge, missed it. Result was a complete system failure. If only I knew then….

I actually missed one I inserted a new #6

1. Assembly work connect wrong and miss
2. QA for the line fail to catch
3. QA Final inspection for deliver miss (what you posted)
4. Dealer Inspection for Pickup delivery ( they may not check hot/cold water but they can check the sheet that you posted. Most cases they are winterized so plumbing checks may not exists)
5. Dealer Inspection upon receipt. ( they certainly should have seen that sheet) If winterized this will not occur.
6. Dealer make ready for Customer
7. Customer PDI

I was fortunate to have spent about a year on this site before buying. I was smart enough to ask a lot of dumb questions. I got earfuls from all of the old faithfuls and knowledgeable ones. I am 100% convinced that the TMC Dealers we worked with knew that we were clueless about RVs and was taking us down the typical boiler plate one size fits all, buy from us TODAY as we are trying to help you sales pitches, because this coach is going to gone tomorrow (Pre covid in 2019 ) Twice we cut checks to buy from TMC dealer and twice we had to walk because the PDIs all failed and Dealer would NOT commit to repair before the sale.

By the time we bought, we really did know what we were doing and our Sales lady at La Mesa RV in Florida was genuine. Something about Florida really was Magical. We started our PDI around 10:30 am and finished around 5:30 pm. I went through everything in the Faulkner PDI guide except for stuff on the roof. At the time, you could NOT pay me to get on that roof even crawling I was willing to accept a leak issue and get it fixed later. I had sent them the PDI list before flying down. So they knew #1 how much we were going to do, and #2 they had a chance to ensure they were ready because they knew we had walked on two prior coaches. So we would become a SOB on this site, but I have had plenty years experience of being a SOB and I think I have mastered it pretty well

[The Gritz Carlton]

Originally Posted by The Gritz Carlton

Check your "bypass" valve near the water heater. Often forgotten when de-winterizing. If left in open position this will allow hot water to "circle-back" into the cold water lines.

Post #4........ Check Bypass Valve...haven't heard if this issue has been resolved but...here's my guess and it still stands.

[ducksface]

My guess is the issue is the op.
She's been flipping valves and is out of sequence somewhere, went to the dealer, was told, didn't listen(No one here believes the shop couldn't fix this) and was summarily dismissed by the service department.
There's a lot to be said when a dealer tells you to go away, we're not working on your coach any more, live with the hot toilet water, we wash(or don't wash) our hands of it.

That's how I read it. It's not that the shop couldn't fix it, it's that they wouldn't fix it.
But
I am often wrong.

All we know is the Shop made her take her rv home unrepaired of a stupifyingly simple repair.