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Replumbing an older coach with PEX

November 09, 2011, 06:20:19 am

Greetings all,

I have done some plumbing repairs/updates since spring - new accumulator tank, new bathroom faucet, shower head, diverter valve, looking to replace the kitchen faucet as well, but am now wondering if I should go all the way and ditch all of the polybutylene piping, replacing it with PEX. I keep imagining plumbing leaks developing when I'm way out there somewhere, and what it might cost for someone else to repair. Interior of the coach is half torn apart now. I redid half my home with PEX (love the Sharkbite fittings) , and have sweated copper in the past, so not a stranger to plumbing, but certainly no expert.

Chlorine has a detrimental effect on poly, and you probably know about all the class action suits and outright banning of it's use in buildings. It seems that it's a case of not if it will leak, but when. As this stuff is already 20 years old, I am concerned.

Not afraid of the work; what spooks me is where the plumbing goes under the floor, travels a ways, then re-emerges in another area. If it's clamped anywhere, it will be a nightmare. Also don't see how the water is connected to the toilet.

Has anyone done a poly piping replacement? Guess I'm looking for tips and pointers, anything to give me a little confidence in attempting this. Thanks.

Steve

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Re: Replumbing an older coach with PEX

Reply #1 – November 09, 2011, 07:15:59 am

I'd chat with James Triana.

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Re: Replumbing an older coach with PEX

Reply #2 – November 09, 2011, 08:32:49 am

Steve, I would not worry about the piping UNLESS the coach has been in freezing temps and not properly winterized or cared for.  I have a 95 and the only two water piping problems I have had were at the fittings.  The gaskets used are subject to aging and cracking when they harden up they have to be replaced.  I have had two problems , one was a broken fitting behind the water bay panel and the other was a cracked fitting behind the Water Heater.  Stuff Happens.. 
Gary B

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Re: Replumbing an older coach with PEX

Reply #3 – November 09, 2011, 09:32:37 am

Thanks for the replies.

This has become an issue in replacing the bathroom faucet. The supply lines to the faucet are higher by about 2 inches, putting a lot of strain on the shower connections. I don't feel comfortable leaving it like this, but if I have to redo any of it, I may as well do it all. The coach was sitting for some time in Florida and I've had to make repairs/upgrades to every system in there. At least the water pump was new when I got it. 

Related to this are items I wanted to add to the water system - strainer on pump inlet, strainer and pressure regulator at city water entry, better drinking filtration system, etc. Making changes like this are complicated by the poly plumbing.

Trying to scope it all out and figure out what to do with this.

Steve

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Re: Replumbing an older coach with PEX

Reply #4 – November 09, 2011, 11:11:34 am

Merle, just curious where you got your accumulator tank? I just bought one at Lowes for $35. I'm getting ready to do same and upgrade all fixtures. Jeff

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Re: Replumbing an older coach with PEX

Reply #5 – November 09, 2011, 11:17:18 am

Merle and Jeff, I threw out the accumulator tank when I replaced the Pump with a Shurflo 5.7, mainly because the pump was bigger and there was no room for the tank. Pump works fine without tank.
A good fix for the Quest piping is to use Shark bite couplers and steel braided water lines like those that you find under your house toilet connection.  These are flexible and don't seem to develop leaks, and they come in all sizes and lengths.  I have found that all the piping except the lines to  a ice maker etc. are 1/2 inch..
Gary B

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Re: Replumbing an older coach with PEX

Reply #6 – November 09, 2011, 11:21:03 am

Steve, if you need a confidence boost I will give it to you---go for it, cannot be too hard with the storage below most areas it goes.
John

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Re: Replumbing an older coach with PEX

Reply #7 – November 09, 2011, 11:52:15 am

Anybody know what year they started using PEX?
Don

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Re: Replumbing an older coach with PEX

Reply #8 – November 09, 2011, 11:55:42 am

Thanks Gary. Saw the poly to pex Sharkbite couplers on Home Depot's web site. Might end up using some of those.

Thank you John. Need some positive waves. 

There seems to be two kinds of accumulator tanks - the first type on my home Reverse Osmosis system, which has a bladder and only holds about 5-7 lbs of air charge, and the well water system type, which is what was in the coach when I got it. The well water type has a diaphragm (better), polypropolene liner, and can hold up to 100 psi air charge. For our purposes (45 psi pump cutoff) it should be charged at 38 to 42 psi. It arrived with a 38lbs air charge.

Link to product brochure --> http://completewatersystems.com/wp-content/uploads/2011/04/HPTANK2.pdf

Best price I've seen lately is here --> Goulds Pumps HydroPro Water Pressure Tank - DiaphragmType, In-line Models -

The downside is it uses a 3/4 inch male pipe thread connection. The old tank had a compression fitting type connection. I used some brass adaptersand a brass compression fitting, only to find out last night that's a no-no with polybutylene tubing.

I like accumulators, because they reduce pump cycling when you're only drawing a little water. They also act somewhat as a system shock absorber.

All the faucet connections use 1/2 inch compression fittings, which can be an issue when it comes to kitchen faucets. Most of the new residential kitchen faucets I've looked at have 1/4 inch or 3/8 pex lines with fittings attached. That won't work with the existing plumbing, especially when there is very little space between the faucet and supply lines, which again have the 1/2 inch fittings. This narrows one's choices down to RV fixtures, and the choices are few indeed.

For small lines I've used John Guest tubing and fittings with great success. They sre like mini-sharkbites -->  John Guest - The World Leader in Push-fit Fittings, Pipe and Plastic Plumbing

Going to get out there and start crawling around, and see what I can see.

Steve

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Re: Replumbing an older coach with PEX

Reply #9 – November 09, 2011, 07:04:12 pm

Ahh, it's been a very long day... allow me to share my findings and thoughts.

As far as replumbing the entire coach - not going to go there. I already have the couch out for recovering, and the icemaker is in the scrap pile - so I could see a fair bit. Also pulled drawers and crawled around until I had a visual reference of where everything went.

For reference, I have a 91 U225 with the booth dinette. Fridge is on the passenger side.

I can access the plumbing around the accumulator and pump, and freshwater lines and valves without too much fuss. But from that area they disappear under a platform and reappear about 6 feet away, at the water heater. It is here where the lines split up for the heater, kitchen faucet, and the bathroom. To access this area you need to pull the water heater, after pulling the icemaker, to access it from outside.

The lines going to the bathroom, disappear under the platform again, and reappear under the sink in the bathroom. The city feed line runs in the same area under the platform in the kitchen. The long and the short of it - you'd also have to take the shelf out under the sink, then rip out the floor, to get at everything.

As far as the bathroom goes, with the new faucet causing a misalignment at the shower connection - am going to redo that with pex tubing and sharkbite fittings. Will be cutting both poly supply lines a little ways after they come out the floor and use the pex to poly couplings Gary mentioned. Note - these aren't too common at Home Depot. No stock in one store, asked the associate to check other stores, came up with only one in a 50 mile radius which supposedly had 45 pieces in stock. They had 5. I grabbed them all.

Will be doing a similar mod with the messed up accumulator connection, with the pex to poly couplings.

[Continued]

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Re: Replumbing an older coach with PEX

Reply #10 – November 09, 2011, 07:15:35 pm

Merle, Sharkbite fittings seem to be Home Depot brand.  At Lowes you will find about the same thing and they are called Gatobite fittings.  There may be other brands out there too.
Gary B

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Reply #11 – November 09, 2011, 07:19:42 pm

As far as faucet and shower connections, finding the right type and length of hose was a headache. Instead, I  found Sharkbite swivel connectors which allow connecting the pex line  right to the faucet. Link --> 1/2 in. Brass Barb x Female Swivel Adapter-UC526A at The Home Depot . They're only $1.98 each, the downside being they are barbed fittings - thus the pex tubing has to be crimped on.

A bag of 25 copper crimp rings is only $6. The least expensive crimping device is $27, made by Sharkbite. You use a pair of vice grips with this unit to progressively crimp the rings to the correct diameter. The package includes a go/nogo gage to make sure you got it right. As I don't know if I'll need to do this often, I opted for this option. Link --> 3/8 in., 1/2 in. and 3/4 in. PEX Crimp Tool-23383 at The Home Depot.

[Continued]

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Re: Replumbing an older coach with PEX

Reply #12 – November 09, 2011, 07:34:07 pm

Hi Gary,

Sharkbite isn't exclusive to Home Depot, although they seem to have the best selection. There are several on-line outlets selling them. I've seen a couple of other similar brands of couplings out there. I don't know if any of the other brands offer a poly to pex coupler.

Conclusions to my rambling and meandering...

While I'm not thrilled about the poly plumbing, replacing it would be a major undertaking, in terms of gaining access. It ain't broke so I ain't gonna fix it, except where I need to.

Poly tubing is long gone. Pex is the best substitute. Joining the two will require either the aforementioned sharkbite coupling or some kind of crimp on fitting. Do not know if a pex barbed fitting will work ok in poly, or if the crimping requirements are the same.

Kitchen faucet - given the plumbing arrangement, an RV faucet will be the easiest to install. One source is here --> RV Faucets for Kitchens, Lavatories, Showers, and Baths - Dura Faucet .

Steve

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Re: Replumbing an older coach with PEX

Reply #13 – November 09, 2011, 08:36:14 pm

Merle, check out Watts Sea Tech fittings they have a 90 degree adapter that is a push together fitting.

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Reply #14 – November 10, 2011, 06:28:48 am

Thanks Bill. Those fittings look like copies of the John Guest series of fittings. I've used the JG fittings a fair bit - like 'em a lot. Never had one leak, and plumbing changes are a snap.

Steve

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Reply #15 – November 12, 2011, 03:04:55 pm

Greetings once again,

Completed the bathroom plumbing redo, thus completing my low budget bathroom makeover. Used the Sharkbite poly-to-pex conversion fittings on the supply lines a little ways up from where they emerge in the cabinet, and redid the lines to the new faucet and showerhead. Cost of the bits to redo the plumbing was about $60 (figuring a portion of the $27 crimp tool needed here).

Spent another $42 in the shower, replacing the diverter valve and adding a new Oxygenics shower head. The original steel sink had a lot of coating missing around the drain and was rusting; a new porcelain bathroom sink was $34 at Home Depot. The original Moen brass plated faucet looked nasty - I found a replacement on ebay - a solid brass, Italian made Danze faucet, a closeout as it was last year's model, $66 with free shipping. I love this faucet, as the head swivels. A fair bit of the mirror coating had peeled away; a local shop cut a new one for me for $20.

Grand total - $222. Looks ten times better than it was.

Also redid the line to the new accumulator with the conversion fitting, some pex line and sharkbite fittings. Done and done. Last to get to is the kitchen faucet and water filter.

Took the freshwater and system drain/fill valves apart, cleaned 'em up and put in new packings and gaskets. Cost under $2.

Steve

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Re: Replumbing an older coach with PEX

Reply #16 – November 12, 2011, 03:18:10 pm

What a great job. And good pics, too. I think I'll do exactly the same... I even have a spare bathroom faucet assembly (in brushed chrome or some-such) to use... and a spare sink (from our shop's apartment construction - which is where we'll be making our home-base in a couple years).

Thanks!
Craig

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Re: Replumbing an older coach with PEX

Reply #17 – November 12, 2011, 03:43:41 pm

You're welcome Craig. 

As to the sink - the old metal one had brackets to hold it down. To secure a porcelain sink to the counter, drop into your local hardware store and pick up a small tube of silicone glue ($5). It will cushion, glue and seal the sink to the Corain countertop.

Steve

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