Water Heater won't fill

[MN-Clark]

Y'all did such a good job with my trailer brake problem. Thx again. Let's see if we can figure out this problem.


De-winterized the RV and set out to check out and test all systems and equipment. Was real pleased to find everything working except one red side marker light. Then I got to the last device to test. The water heater.


It will not fill. Hooked up to the house water. Heater bypass in the off position (i.e., do not bypass). After an hour there might be a gallon I can drain from the WH's anode rod hole. As far as I can tell, all water devices are getting water. Both H and C if bypass in the on position, only C if bypass in the off position. I've been looking at the water line connections on the back of the water panel and can't see anything suspect. The on board pump works just fine too.



Is there a gunked up water line someplace? Maybe the sanitize & flush stirred up gunk that plugged a line? I don't get it.


Of course testing the WH is the last thing to test. And of course my beautiful bride & I had planned on a 10 day birthday getaway (hers) starting next week. And of course we won't go anywhere without our own hot water.



Do I need to find a sacrificial goat?

[travelin texans]

Could be the check valve on the hot outlet side of the heater is stuck shut or partially stuck if you're getting some water from the hot faucets.

[MN-Clark]

I fixed it!!!!


Can't explain why this worked but here's what I just did. First though, I need to say that my beautiful bride is happy again. Whew!


I thought if I could fill the WH somehow maybe a little gravity back pressure would have a positive affect. So I pulled the anode rod, stuck the house hose in, held it as tight as I could and waited to get water from the pressure relief valve. While waiting, it occurred to me that the water pump might help put a bit of negative pressure on the WH. When the WH was filled and the anode rod replaced (most of the water I spilled landed on me) I turned on the water pump, went to every faucet and ran H only then C only then more H only. This bleed a bunch of air from the lines. BUT with all valves in normal operating position, I have water running from the H faucets! I then drained and refilled the WH, checked all faucets again and turned on the WH. Several minutes later, hot water from the hot faucets!


We're going camping next week!!!

[bobbecky]

It would really help if you would add info in your signature area that at least tells what your trailer is, year and model. Trying to diagnose problems a lot of times is dependent on this info.

[MN-Clark]

Originally Posted by bobbecky

It would really help if you would add info in your signature area that at least tells what your trailer is, year and model. Trying to diagnose problems a lot of times is dependent on this info.

Good point. Thanks for reminding me. I'm on it!

[MN-Clark]

One additional point on this problem. There is an RV dealer / repair shop a few miles from me. I had called them to see if I could talk to a technician about this. I have delt with them before and found them to be very good people. Anyway, I described the situation and what I had done. When I told them that I wasn't sure what the real problem was but if I were to take a guess that vacuum played a role here, the tech chuckled and confirmed my suspicion. Said it was a common problem when dewinterizing & sanitizing.



I'm going with that explanation. Lesson learned.

[MN-Clark]

Why doesn't my signature info show up here? I added lines to identify my equipment. Hummm . . .

[bobbecky]

Go to User CP, then edit Signature, and then save it.

[ChuckS]

Glad you resolved the issue.. I really don't think vacuum inside the water heater was your issue.. What I really think the issue was all the time was a stuck one way check valve on the outlet side of the water heater...

When you drained the tank with some water in it that sudden draw most likely was just enough suction to unstick that stuck check valve...

Once that valve could now open as cold water flows into the tank the the air is displaced out the outlet side ( with a hot water faucet) open to allow air to escape...

I would plan on replacing that check valve in the near future before it sticks again and you have no hot water...

[JRTJH]

Originally Posted by ChuckS

...

I would plan on replacing that check valve in the near future before it sticks again and you have no hot water...

I agree. This is one of those "parts to buy and put in the trailer for when it will need replacement"... I wouldn't delay a planned trip to change it out, but I'd make certain the part and all the tools needed to change it are "in the trailer for that Saturday afternoon when we don't have hot water"... Then, once this planned trip is finished, if there's a "free Saturday afternoon" I'd go ahead and change it out. It's much better to do it "at your convenience" rather than "when it breaks at the worst possible time".....

Sooner or later, it's going to "slap your fanny with an I told you I'd get you"....

[jasin1]

Originally Posted by JRTJH

I agree. This is one of those "parts to buy and put in the trailer for when it will need replacement"... I wouldn't delay a planned trip to change it out, but I'd make certain the part and all the tools needed to change it are "in the trailer for that Saturday afternoon when we don't have hot water"... Then, once this planned trip is finished, if there's a "free Saturday afternoon" I'd go ahead and change it out. It's much better to do it "at your convenience" rather than "when it breaks at the worst possible time".....

Sooner or later, it's going to "slap your fanny with an I told you I'd get you"....

How many different styles of check valves does keystone use? Is there one or two standard ones? I guess I should take a look at mine and get what I need for the future.
I also thought about getting a extra electric motor for the auto levelers unless that’s something that rarely ever goes up
On second thought they are pretty expensive to keep laying around

[flybouy]

Originally Posted by jasin1

How many different styles of check valves does keystone use? Is there one or two standard ones? I guess I should take a look at mine and get what I need for the future.
I also thought about getting a extra electric motor for the auto levelers unless that’s something that rarely ever goes up
On second thought they are pretty expensive to keep laying around

A 1/2" check valve s a 1/2" check valve. As for the auto level motors where do you stop? If you want to carry spares for everything then you'll need a chase van like MC clubs use to follow and keep the bikes going.

[jasin1]

Originally Posted by flybouy

A 1/2" check valve s a 1/2" check valve. As for the auto level motors where do you stop? If you want to carry spares for everything then you'll need a chase van like MC clubs use to follow and keep the bikes going.

Oh sh#!.... you don’t have a chase van? ...I thought everybody had one
I know I don’t want to carry everything BUT I like to have spares of hard to get items. I figured few things can cause a ruined trip but slide motors and leveling motors are probably up there although I guess I could just use a bottle jack in a pinch for levelers.
My trips have a defined start and finish, I don’t have the luxury of extending a trip to wait for parts and I don’t want to come home early if we planned for months on a trip. I think my kitchen slide is the most important.

[flybouy]

Originally Posted by jasin1

Oh sh#!.... you don’t have a chase van? ...I thought everybody had one
I know I don’t want to carry everything BUT I like to have spares of hard to get items. I figured few things can cause a ruined trip but slide motors and leveling motors are probably up there although I guess I could just use a bottle jack in a pinch for levelers.
My trips have a defined start and finish, I don’t have the luxury of extending a trip to wait for parts and I don’t want to come home early if we planned for months on a trip. I think my kitchen slide is the most important.

We had a chase crew but the beer got too expensive so I had to lay them off. Like everything in life it's a matter of finding the right balance. I know I tote way more stuff than I truly need but agree it's nice to have it when you need it. Two things that are pretty much truisms ... 1. You'll find what you are looking for in the last place you look. and 2. You can carry 99% of the trailer in spares and it will be the 1% thing that breaks.

[JRTJH]

Originally Posted by jasin1

How many different styles of check valves does keystone use? Is there one or two standard ones? I guess I should take a look at mine and get what I need for the future.
I also thought about getting a extra electric motor for the auto levelers unless that’s something that rarely ever goes up
On second thought they are pretty expensive to keep laying around

I wouldn't "buy a check valve for a water heater" IF THERE IS NO PROBLEM WITH THE CURRENT CHECK VALVE....

The OP has a sticking check valve and it's just a matter of WHEN (not IF) it fails again. If I were him, I wouldn't delay or cancel a planned trip just because it "might fail"... I would recommend to HIM (not everyone with a water heater) buy a check valve to fit HIS water heater (look up the part number in the owner's manual for HIS water heater to buy the correct part). Keep it handy while on that trip and if it fails, it's an hour job to replace it since the part is already in the trailer.... If it doesn't fail on the trip, then replace it when he gets back home and has an open afternoon....

As for a recommendation that ALL OF US run out and buy a check valve.... That was NOT my intention.... I've only had one check valve fail on a water heater that I own. That was on a 12 gallon Suburban that was in a 93 motorhome that we owned almost 30 years ago.... I don't carry a spare check valve and wouldn't recommend carrying one for most people....

That said, the OP's check valve is sticking and has almost cancelled a trip. For him, I'd recommend getting a replacement "sooner rather than later, on a Sunday afternoon, 1000 miles from home, far away from the closest RV parts store".....

ADDED: As to "which valve to buy", for MY water heater, it's the standard 1/2" brass valve. Valterra has a replacement that's sold on Amazon for $13 https://www.amazon.com/Valterra-P234...17733165&psc=1 or you can buy it at any RV parts store for around $7.... Double the price for a 2 day wait but saves a trip to the RV dealer.... Same part both places. Valterra # P23415LF

[MN-Clark]

We are camping now so I'll look for a check valve when we get home. I didn't see anything that looked like one when I was working on things though. Thanks for the link,too.

[ObiRich]

Next time, if you're on city water, open the pressure valve and let the air out. Close it when water comes out. Alternately, open up a hot water faucet inside and the air should come hissing out. With water being a sealed. pressurized system, with 6 gallons of air in the HW tank, it won't fill with water.

[Corky]

Well done on the critical thinking aspect...something for me to put in the file in case I should have to face the same problem.

[Javi]

Originally Posted by ObiRich

Next time, if you're on city water, open the pressure valve and let the air out. Close it when water comes out. Alternately, open up a hot water faucet inside and the air should come hissing out. With water being a sealed. pressurized system, with 6 gallons of air in the HW tank, it won't fill with water.

Just a note. Water expands as it warms so the tank is designed to have an air gap, so opening the over-expansion valve during filling is counterproductive. It is best to just open a faucet until water flows evenly.

[LHaven]

Originally Posted by jasin1

I don’t want to carry everything BUT I like to have spares of hard to get items. I figured few things can cause a ruined trip but slide motors and leveling motors are probably up there although I guess I could just use a bottle jack in a pinch for levelers.

A more proportionate (and much lighter and cheaper) stopgap would be a cordless drill/driver, the proper socket to turn the leveler motor manually, and a brief hands-on familiarization session with the manual and the jacks so that you can be sure you know where the manual ports are located and make sure your socket can reach into them and turn them.

My last rig had four manual scissor jacks, which I worked for 20 years. If I had to work one manually until I got it somewhere I could replace it, I suspect I'd still feel like I came out ahead.