Looked everywhere for small leak behind UDC, can't find it?

[ParkIt]

Looked everywhere for small leak behind UDC, found it! (easy to miss)

Not sure what the deal is but had a full tank of fresh water and the heater on, it worked until earlier tonight.
Backing up a bit...before the cold weather hit I pulled the panel blocking the UDC/water pump/HW tank and there was a slight amount of moisture right around the UDC carpet going towards the front (away from the pump etc). One towel and a small space heater for a couple of days it dried out and stayed dry, I couldn't find anything except the filter cover on the water pump needed tightening.

Lately the weather has warmed up so I turned off the space heater and when I didn't have any hot water and noticed the propane isn't kicking in again, I checked the carpet and it was damp in the same place.

Baffling thing is it looks like its coming from the outdoor shower hose behind the UDC...I've checked every fitting, the pump, all lines and its all tight (all replaced with brass this summer) so I really have no idea where its coming from. Since getting it over insulated a month or so ago where everything thawed gradually, I checked then and didn't find anything out of the ordinary - no leaks.

What am I missing?
*Checked propane - one full tank running to the stove and house heat just fine
*Checked all fittings - all dry
*Checked water pump - dry
*Damp area is to the right of the UDC if you are looking at it from the back side
*Condensation couldn't cause that much of an area nor shut down the water heater (the one that heats it off propane, not the electric rod)
*Triple checked all the schematics in the (awesome) links to the PDF's
* Am hearing a weird high pitch buzzing that sounds somewhere between the UDC plywood and the water heater

Any suggestions would be very helpful, thanks!

 

[donr827]

Sometime the leaks are so small that that they are hard to insolate. When I had a similar problem I wrapped all the fittings in toilet paper. The following day I found the toilet paper around one fitting was wet.
Don

 

[ParkIt]

Good suggestion though I will probably have to put some foam blocks between all the lines since they cross around - one could be leaking but running down another.
Thanks!

 

[danemayer]

Hi Parkit,

Do you have 2 problems? A slow leak and the water heater won't run on LP even though the furnace runs ok?

On the water heater running - have you pressed the reset buttons and does it work on electric?

On the leak, do you have a plastic check valve on the water heater HOT outlet?

Our Water Heater Troubleshooting Guide may help.

 

[ParkIt]

Yes Dan, it's two problems of a slow leak and something tripping the water heater pilot to not stay on. It happened this summer when I first got it back from the fittings being changed to brass, not the leak but the propane and I can't figure that one out because I don't have a 'reset' button...where its marked there is one (its a solid piece of metal with a rubber boot over the top).
The plastic check valve was replaced with brass this summer as well, dry.
Went through the Troubleshooting guide since I printed and saved those as you've been putting them up.

This morning for the heck of it I turned on the water heater and heard the propane kick on and the floor is almost dry from 7 hours with a space heater on low. I'm really baffled on this one.

 

[cookie]

One thing to consider is that if you over insulated there is a possibility that condensation is forming.
Just a thought.

Peace
Dave

 

[piet10]

Is it possible that the pressure relief valve could be leaking? If the high limit switch trips a little high and the pressure valve opens letting some water out, you could get what looks like a small leak. Or, maybe the pressure relief valve is just a bit weak or you've lost the air pocket at the top of the water heater?

These are the only 2 components I can think of that when linked could cause your problem.

Al

 

[danemayer]

I don't have a 'reset' button...where its marked there is one (its a solid piece of metal with a rubber boot over the top)

That's weird. If it's a Suburban water heater, with the boot off, it should look like the picture below.

When it stops working, does the red light illuminate at the control panel switch? That would indicate a safety lockout. It tried to ignite several times and failed. Things to look for would include dirt or other obstructions in the gas orifice, 1/8" gap for the direct spark ignition electrode, loose wires.

If no red light in the control panel, then it's possible something is preventing the ignition sequence from starting. The most likely cause is an open thermostat/eco assembly. It could also be the gas control solenoid or the circuit board.

 

[olcoon]

Had a similar problem with ours. Kept getting wet carpet around the UDC, couldn't find anything & it was sporadic. Finally one day I found one of the valves for the outside shower was slightly on, (we've never used the outside shower). I tightened it, & sometime later I had wet carpet again. After this happening a few times, I got behind the UDC, and put shut off valves on the shower lines & haven't had a problem since. Also I think the water from inside the UDC was leaking out the bottom into the area behind the UDC, so I put a bead of caulk all along the bottom.

 

[ParkIt]

Is it possible that the pressure relief valve could be leaking? If the high limit switch trips a little high and the pressure valve opens letting some water out, you could get what looks like a small leak. Or, maybe the pressure relief valve is just a bit weak or you've lost the air pocket at the top of the water heater?

These are the only 2 components I can think of that when linked could cause your problem.

Al

That is a good possibility, I'll check but so far those lines have stayed dry.

That's weird. If it's a Suburban water heater, with the boot off, it should look like the picture below.

When it stops working, does the red light illuminate at the control panel switch? That would indicate a safety lockout. It tried to ignite several times and failed. Things to look for would include dirt or other obstructions in the gas orifice, 1/8" gap for the direct spark ignition electrode, loose wires.

If no red light in the control panel, then it's possible something is preventing the ignition sequence from starting. The most likely cause is an open thermostat/eco assembly. It could also be the gas control solenoid or the circuit board.

Dan, mine doesn't look like that in the picture at all. The solenoid and contacts are still solid though I've been meaning to switch the whole thing over to an electric one as I did in my RV. On this unit, the red light is always on when you turn the rocker to "on" (heating). Now that its working again I'm still at a loss since its only the 2nd time its happened, 6 months apart.

Had a similar problem with ours. Kept getting wet carpet around the UDC, couldn't find anything & it was sporadic. Finally one day I found one of the valves for the outside shower was slightly on, (we've never used the outside shower). I tightened it, & sometime later I had wet carpet again. After this happening a few times, I got behind the UDC, and put shut off valves on the shower lines & haven't had a problem since. Also I think the water from inside the UDC was leaking out the bottom into the area behind the UDC, so I put a bead of caulk all along the bottom.

I need to try this since I don't use the outside shower and shut off lines would be better IMO. There was some water in the UDC (looking at it from the outside) and I've wondered about that as well. What I still need to track is that high pitch sound I could hear when it stopped working, now that its working again I don't hear it. That could be part of the water heater circuit which I guess I'm just going to have to swap out.

Thanks for the suggestions and good to know it isn't just me that has had such a weird problem.

 

[HornedToad]

On the leak, do you have a plastic check valve on the water heater HOT outlet?

I had a real slow leak that I could never find.

CW fixed it under warranty and told me it was the water heater by pass value you open when you winterize.

 

[ParkIt]

Was just under there again and it seemed the water wasn't drying up...with both doors open the sun hit it just right and I finally found the leak. Not sure how to fix it yet since it's the city water connection on the back side of the UDC, a small black plastic tab holds it on the backside exactly where its leaking. The other lines are dry, I've always had a pressure regulator and monitored that as well. Good thing I noticed it early on and have been checking it regularly or I'd have a rotted floor and bigger mess!

I'm thinking at this point the only option is to remove both city water fill and tank fill (connected to the same line with a T) fittings and replacing them with something but not quite sure what since it's an actual tab that it sits on to the front of the UDC. When my son has time I'll ask him to come check it out, its good to have a plumber in the family. We checked it all out when it arrived in 2011, he said it looked pretty solid and the lines tested at 123psi but I don't let the regulator run that high...just in case.

This also makes me wonder if it dripping that high was splashing on the line that runs to the water heater since it also ran down the MDF over the satellite and cable connection lines as well (yea, that isn't going to be fun). It would make sense: last spring/summer when the same problem started the temps shot up to 100º staying 80-100 until October and I'd have the water on then off when I'd head home through the week. That is enough for it to dry out and stay dry as well as the water heater connection staying dry too.

Oh, the two screws on the UDC had NO silicon on them and the standing water in the bottom was also leaking to the carpet so I get to fix that too. At this point, it seems I'm going to have to essentially re-install the UDC which kinda sucks in the middle of winter.

Thanks for the tips and unusual warm, sunny day. I think I got it figured out but not entirely thrilled about it.

 

[stan.nations]

Check your outside shower head. I found water running out one day and the shower head was open. It seems that thumb button will get stuck.

 

[FlyerChief]

Check your outside shower head. I found water running out one day and the shower head was open. It seems that thumb button will get stuck.

I had exactly the same experience.



Sent from my iPad using Tapatalk HD

 

[ParkIt]

Thanks but checked that round one, everything was tight. The real trick was the sun hitting it just right - I could see which line it was leaking from and its the city water connection.
Can't say I've heard much about that one going south but if you look close (might not be on other years), the back slips in a black 'clip' like plate unlike all the other connections and I can see damage from pressure applied most likely when it was installed.

Not even sure how to fix that and since its plastic, I'd rather swap it out anyway to brass.

 

[brianharrison]

I had a leak at the city water threaded connection (could not tighten it enough with hand strength) and it would leak past the back of the connection and into the area behind the UDC. I guess there is a pathway!?!

My solution was to use a 45 degree brass threaded adapter with teflon tape into the city water connection, with wrench and it fixed the problem. I now connect my water hose to the brass adapter, which is easier. If it leaks it stays outside the basement.

Brian.

 

[ParkIt]

I have one of those on there because the angle was funny to start with, I think it was the very 1st round of things I did right after delivery. I didn't want to put too much torque on that head outside for the hose since its rather soft to begin with.

 

[JohnDar]

That black plastic clip on the city water connection (if it's what I'm visualizing) is merely the retaining clip to hold the fitting in place. It should slide off with a bit of effort and the fitting will be loose. If the fitting is plastic, replace it with a brass one (available at most RV parts stores).

The buzzing noise you mentioned is curious. Maybe it's the pressure relief valve on the water heater. If you have a Suburban water heater, there is a control module stuck to the back (usually) of the water heater that controls the 12V operation. Those can go bad and the connector can also come loose. The electrical connectors on the gas valves in the front can also oxidize. Cleaning them and applying a contact protectant may help. The Hi-limit 12V and 120V thermostat switches should look like the ones Dan posted. I ended up replacing my 12V one last summer.

Some photos of your UDC (front and back), as well as the water heater and control panel would be helpful. From some of your posts, it sounds like you have something different (or I'm again visiting the state of Confusion).

 

[ParkIt]

That black plastic clip on the city water connection (if it's what I'm visualizing) is merely the retaining clip to hold the fitting in place. It should slide off with a bit of effort and the fitting will be loose. If the fitting is plastic, replace it with a brass one (available at most RV parts stores).

Thanks John, was hoping you'd weigh in. Our crack fix-it guy on the forum that I figure has replaced just about everything on the unit
Didn't know I could get that in brass (going to have to check who would carry them in the area) and I tried to see if it would slide out. Nope. That's when I noticed too much pressure was applied slipping it in so I better have a replacement part handy.

The buzzing noise you mentioned is curious. Maybe it's the pressure relief valve on the water heater. If you have a Suburban water heater, there is a control module stuck to the back (usually) of the water heater that controls the 12V operation. Those can go bad and the connector can also come loose. The electrical connectors on the gas valves in the front can also oxidize. Cleaning them and applying a contact protectant may help. The Hi-limit 12V and 120V thermostat switches should look like the ones Dan posted. I ended up replacing my 12V one last summer.

Some photos of your UDC (front and back), as well as the water heater and control panel would be helpful. From some of your posts, it sounds like you have something different (or I'm again visiting the state of Confusion).

I think you are correct about the electrical connectors and oxidizing which would also explain the high pitch sound I heard (which probably only dogs can hear). It might be from too much moisture at the time which would cause it to shut off instead of shorting out. All that will be traced and re-done anyway, I've got an idea and been sketching it out for that part of the unit

Thanks again!

Edit: I'd take pictures but my camera is acting up, the focus isn't working properly and a fuzzy picture won't help at all.

 

[JohnDar]

Thanks John, was hoping you'd weigh in. Our crack fix-it guy on the forum that I figure has replaced just about everything on the unit

Ha ha! I've gotten most of my fixes, upgrades and PM ideas from this forum. Reading about the problems of others gives me things to keep an eye on that I might not have. And so far, my problems have been relatively minor.