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Topic: What is the purpose of this HWH Tank Solenoid? (Read 1287 times) previous topic - next topic

What is the purpose of this HWH Tank Solenoid?

Am struggling to isolate an annoying air bleed down in my HWH circuits.  Nothing leaking externally, but every check valve I've serviced has been full of corrosion and is toast.  Replacing them as I go.

My factory system did not incorporate a desiccant drier, just a condensing filter, and the entire system is full of water and corrosion.  I'm adding a desiccant filter to the system after I clean it all out and replace failed components.

I have several questions.  Roger posted a diagram (which I don't have in my documentation anywhere) which I've included.  It shows a solenoid between the 12v compressor and the HWH tank.  My 2001 HWH wiring diagram does not show this solenoid, nor does the HWH air schematic.  The coach does have such a solenoid and the wiring is so marked (see photo) from factory.  This solenoid is normally open.  What is the conceivable reason for this solenoid?  And if normally closed, wouldn't a check valve serve the same function? 

Also my system had an adjustable regulator installed just after the pump, before the condensing filter, that was acting as a pressure relief valve I guess.  It too was full of water and corrosion.  No pressure gauge.  Dumb design.  (see second photo)  Does anyone have a photo or two of their install in a 2000-2002 slide out air system before I redesign this water trap from scratch???

Also attached the schematics in question.

Thanks in advance....Woody.

Re: What is the purpose of this HWH Tank Solenoid?

Reply #1 –
I'll try and get u a couple pics of ours, tomorrow AM. The compressor, only, is out for a rebuild but that should provide a better view of the subject at hand.

Re: What is the purpose of this HWH Tank Solenoid?

Reply #2 –
Hi Woody,

There were three different air systems in the 2001 U30s as far as I can tell.  Your B-2193 looks the the right schematic.  You can see what build number it begins at (CN number) in the the title box in the lower right corner.

The electrical diagram is for one or two systems later.  I have attached the one that is for your coach (0592) as well as a compressor drawing (0593).  The later electrical drawing  includes a switch to open or close a solenoid that feeds air to the wet tank.  You don't have that.

The thing that looks like a regulator is an adjustable pressure relief valve.  The NO solenoid valve in your system closes when the HWH system calls for leveling air. This redirects all of the air compressor output to the level system manifolds.  In later systems with a bigger compressor this solenoid valve is not there.

I am in the middle of rebuilding my compressor and water trap.  I will post a pic later.  I am moving the pressure switch, relief valve, water trap, desiccant container (new), 5 micron filter, and distribution connections to the rear wall of the main bay, drivers side left of the HWH pump.  That makes all,of that much more servicable.  The only thing left on the shelf is the compressor and the Essex relay.  I am adding a NC solenoid valve and wiring shown in your drawing so that I can run an air line to the wet tank if I want.  I changed the wiring just a bit so that the compressor can actually be shut off from the dash as well.

I have pressure gauges at the compressor output, the HWH tank and in the air line from the slide bladder manifold to the bladder. 

 

Re: What is the purpose of this HWH Tank Solenoid?

Reply #3 –
Woody,

 Here's a couple pic of ours. The line from the solenoid below the pressure switch goes to the HWH storage tank.

Re: What is the purpose of this HWH Tank Solenoid?

Reply #4 –
Thanks Roger and Greg.  That's exactly what I needed to see...my system looks unadulterated factory.  Now to go through all the rusty bits and get it put back together with a desiccant filter inline so this won't happen again.  Looking forward to seeing the modifications you are doing Roger as they are along my lines of thinking.  I would like to flip the rack around on the bracket so that the pump is against the bulkhead and filter bits are out in the bay for service.  Will let you know if that works.  Thanks and Aloha,  Woody.

Re: What is the purpose of this HWH Tank Solenoid?

Reply #5 –
Quote from: Pyolet –
Thanks Roger and Greg.  That's exactly what I needed to see...my system looks unadulterated factory.  Now to go through all the rusty bits and get it put back together with a desiccant filter inline so this won't happen again.  Looking forward to seeing the modifications you are doing Roger as they are along my lines of thinking.  I would like to flip the rack around on the bracket so that the pump is against the bulkhead and filter bits are out in the bay for service.  Will let you know if that works.  Thanks and Aloha,  Woody.
Just bought 2 of them Haldex KN23080
HALDEX One-Way Check Valve KN23080 | eBay

My original ones I cleaned up but yours doesnt look like it can be

Re: What is the purpose of this HWH Tank Solenoid?

Reply #6 –
FindItParts. A great resource.
KN23080 by HALDEX - CHECK VALVE

$28 each less 10%.  Got here in 2 days. Free shipping but I had to pay for "handling".

Re: What is the purpose of this HWH Tank Solenoid?

Reply #7 –
Thanks for the check valve links.  I disassembled the original check valves to clean them...unfortunately the rust got under the rubber coated flapper and rendered them toast.  Bought these repair kits from same source last week.  For a few bucks more could've replaced the whole valve with those David and Roger listed. 

RN10Y by HALDEX - KIT-REPAIR
 
 They did the trick for now.  Hopefully the desiccant will keep this from happening in the future. 

Re: What is the purpose of this HWH Tank Solenoid?

Reply #8 –
One last picture.  This is what the inside of my pressure regulator/pressure relief looked like.  Why this was designed and installed before the condensing filter is a mystery.  I think I'm going to toss this and replace it with a pop off valve like those found on air compressors.  Woody.

Re: What is the purpose of this HWH Tank Solenoid?

Reply #10 –
Quote from: Pyolet –
One last picture.  This is what the inside of my pressure regulator/pressure relief looked like.  Why this was designed and installed before the condensing filter is a mystery.  I think I'm going to toss this and replace it with a pop off valve like those found on air compressors.  Woody.
Weather u decide to replace it with a pop off, or another regulator, put it after your filter/desiccant to reduce moisture damage. It will provide the same function. FT used several of those 1/4" NPT 15 CFM regulators on our coach. The one that is in line 38 that supplies the front six pack gave up on ours yesterday. I ordered a couple from Grainger. (1 spare)

Re: What is the purpose of this HWH Tank Solenoid?

Reply #11 –
I am moving the air system parts except the compressor to the rear wall of the main bay on the driver's side.  Much easier to service and access.  I added a desiccator, a 5 micron filter and a NC solenoid and air line to the wet tank as well.  This makes this this part like the air system in the 2003s.  The compressor is still on the shelf along with the Essex relay.  I am switching to the bigger compressor while I am at it.

Re: What is the purpose of this HWH Tank Solenoid?

Reply #13 –
The bigger Thomas compressor is really sturdy.  I had several parts of the old system that needed replacement and when I came across this compressor for about 1/2 price (new, in the original packaging) I just went for it.  I like the way the 03s are done but not with the compressor on the floor of the bay so this is the best of both.  Upgraded circuit breakers and wiring, Two new switches up front, one turns the pump off, the other allows ait to go to the wet tank when the pump is on. I have pressure gauges for the bladder, compressor and the HWH tank.  I am replacing all of the check valves and pressure protection valves as well and a few other leaking fittings.

Re: What is the purpose of this HWH Tank Solenoid?

Reply #14 –
Very sanitary installation Roger! The plumbing is obviously more complex on the systems with a slide, and may possibly even be different on the non-slide U320 vs. the U270 of the same year. Ours did not come with a desiccant system, just a water separator and pressure relief. I bought, but have not yet installed a Devilbis QC3 Filter & Dryer Unit to add to our aux compressor setup. The complication is that the instructions say that the unit should ideally be installed about 30' from the compressor. This to allow the air too cool and thus the moisture to condense before entering the filter/dryer unit. This not an option for the aux compressor in our coach unless I run tubing around the circumference of the storage bay. I have considered getting an A/C condenser and using it as an air to air intercooler to keep the plumbing connections close to the aux compressor, but felt I needed more time to research the idea. Probably overthinking it... FOT doesn't have thirty feet of air line to allow for moisture condensation in the OEM systems. So in the mean time, the ARB Twin compressor Tim linked to is just plumbed into the system the same way the original anemic Thomas was. My main consideration for putting the higher capacity aux compressor was that I wanted to be able to raise the coach high enough to put in the frame blocks without running the engine. This perceived need came about as a result of the air dryer for the engine mounted air compressor failing and and not being able to build air pressure above 30 PSI. I had to improvise an air dryer bypass by the side of the road without being able to raise the coach.  Try as I might, I could not raise the rear of the coach significantly with the OEM compressor. With the ARB Twin, I can get it high enough to put the blocks in. It takes awhile, but is doable. When we get back, I will bump the installation of the Devilbis QC3 Filter & Dryer Unit up the project list, even if it means installing it without the recommended length of piping between the compressor and the filter/dryer.
Don
Quote from: Tim Fiedler –

I think Don went to the ARB 12v continuous duty compressor when he upgraded his pump, maybe he will chime in

http://www.summitracing.com/parts/arb-ckmta12/overview/

Re: What is the purpose of this HWH Tank Solenoid?

Reply #15 –
Don, the only difference in my year, slide or no slide, are the controls in the HWH box for the slide bladder and an air line to a slide bladder manifold.  Other than adding a pressure gauge to monitor bladder pressure and a valve to isolate the bladder I haven't done anything with that system. 

In very late 2001, and certainly in the 2000s and beyond FT added a bigger compressor and a line to the "wet" tank.  The desiccant air dryer was added as well as the 5 micron filter (which is also an air separator) probably to make sure air was as dry as possible.  The 2000s had an air operated patio awning and more than one slide. That awning was only used in 2002.  All of this plus other equipment was mounted on the floor of the main bay using up about 1/4 of the floor space, a significant loss of basement storage. 

This arrangement in my coach uses no basement space not already committed to anything else.  The compressor comes out with just 4 bolts from below using T nuts above so no wrenches to hold a nut, one air line and two electrical connections.  Way easier than the original.  The filter and distribution panel comes off as well in one piece if need be and all components are serviceable from outside of the bay. 

All of this to improve performance and functionality in our coach for the way we want to use it. 

Re: What is the purpose of this HWH Tank Solenoid?

Reply #16 –
Thanks everyone for the replies.  It helps a lot.  I have been scratching/slapping my head frequently at the engineering, or lack thereof, and thought processes that went into the entire HWH air system, along with the lack of significant improvements over the years.  What Roger and others have done in improve upon what FT supplied to make the coaches "right" and live longer.  Kudo's and immeasurable thanks again to all of you "rocket scientists and brain surgeons"!!!
 

Re: What is the purpose of this HWH Tank Solenoid?

Reply #17 –
Thanks, Woody.  Send me a PM if you have questions.  Glad to help.