Water System Installation

[Scott T-Bird]

Well, I'm finally getting "A Round Tuit" ... pressurized hot & cold water system install. Instructions rarely fill the gaps where my mind runs, I think, so I figured I'd ask them here.

1. I got one of those small accumulator tanks to even out the flow. The built-in fittings are the 1/2" male threads. The package came with this little female adapter thingy, and I don't know if there is any real purpose for it. The instructions also indicate that the tank can be installed in-line after the pump, or it can be installed off-line on a tee after the pump. Since the purpose is to even out the pressure, is there any preference? I guess I'd have to buy a cap for the other end if I install off-line. What is that adapter for? I'm assuming that I need to purchase an adapter for the connection to PEX anyway.

2. The Pump instructions indicate that it is preferable to connect a flexible water line within at least 18" of the pump. I am assuming that PEX is NOT considered flexible (or is it?). In that case, I figure that the conduit from the tank to the pump will be a flexible hose. I could start with PEX just past the accumulator, no?

3.The water heater instructions seem to indicate that the in-flow and out-flow from the heat exchanger are thru "adaptors to avoid restrictions", rather than a 90 degree elbow. I want to run the lines down under the platform and make a few bends to turn them back up to the engine. Better to do with flexible hose rather than bend fittings (probably a stupid question ) or is a fitting with a 90 not considered a restriction? (I do consider it a restriction). I plan to use Shields Series 250 for the heat and flexibility.

I'm mounting the tank horizontally on a platform just above the hull.

 

[Terry Cox]

Hi Scott, our boat does not have an accumulator tank. Not sure that I need one. Basically, we have a water tank(s), that connects to a water pump screen type filter, then the water pump followed by the assortment of water dispensers/faucets. Hunter used Zurn PEX throughout our 1991 boat and the product when installed correctly will last the life of the boat. Durable, flexible and simple to install/repair.

We also have a hot water heater that uses either the engine coolant or shore power to heat the water. This arrangement makes for a comfortable living boating environment. The Zurn PEX hose does have flex to it, but Hunter used 90/45/30 degree fittings to make the sharper turns encountered in a boat.

 

[Stu Jackson]

Scott, nice move. One "habit" to get into when using the electrical: only turn it on for as long as you need to heat the water and then turn the power to the heater off.

Another good habit: even if there is NO hot water, use the hot faucets to keep the water moving thru the heater to avoid rotten egg smell:

Fresh Water System Recommissioning 101 - Peggie Hall's "Cocktail" Rotten Egg Odor

http://c34.org/bbs/index.php/topic,5836.0.html

I agree with Terry that an accumulator is not required. I've learned to love the sound of the pump, since if it does go ON when not expected, I know right away. We turn the power to the pump OFF when we go to bed. If you have one and want to put it in, put it after the pump. That's the pressure the pump is seeing, not the inlet. See the WM Advisors.

 

[Stu Jackson]

or is a fitting with a 90 not considered a restriction? (I do consider it a restriction)

An elbow is not a restriction, it is simply a longer "equivalent length" of pipe. My reference manuals are packed up for my move, but it's like adding four or five feet of pipe to the system, not an issue.

 

[Ron20324]

Face it, any fitting installed in a pie/hose drops down its effective size, even if for a little bit. If you want full service, use continuous hose without fittings, or full-flow fitting. Even full-flow is a bit restrcitive. This even applies to vent lines.

 

[Scott T-Bird]

An elbow is not a restriction, it is simply a longer "equivalent length" of pipe. My reference manuals are packed up for my move, but it's like adding four or five feet of pipe to the system, not an issue.

Good point, Stu, for the water pipe, it is just friction head. Still, I'm using the Shields Series 250 hose for the engine connection and it is bendable without kinking to 2-1/2" radius for the selected diameter, so I think I will just make those bends by sweeping the hose.
Based on commentary, I decided the variable speed pumps can be more trouble than they are worth, and West Marine and others said the accumulator does make a difference in evening-out the pump operation, since I'm using a fixed pressure pump. It's light and small and easy to install in-line after the pump (and not very expensive) so I figured I would go for it.

I guess I could consider PEX as flexible pipe. It's not rigid like PVC or copper. I have a bunch left over so that's why I want to use it.

You're moving? Sue and I just downsized into a nice, tidy townhouse in the mountains. We took a year to remodel and sell our house. We worked for a full year and sold in 15 days on the market. What a relief! No more lawn care, no more snow blowing, no more spreading mulch, cutting logs, splitting & stacking! No more trips to the woodshed (literally!) to keep the firewood bin filled! No more basement remodeling project, painting, fixing. Hopefully it's just sailing, skiing, biking, travelling from now on! Now if I could just retire! (Sue doesn't want to retire yet but she was the driving force to move into a new place).

 

[Scott T-Bird]

Face it, any fitting installed in a pie/hose drops down its effective size, even if for a little bit. If you want full service, use continuous hose without fittings, or full-flow fitting. Even full-flow is a bit restrcitive. This even applies to vent lines.

I'm more concerned about the heat exchange hose than I am for the water service lines, therefore I will minimize the fittings. It looks like I just need a hose clamp at the engine nipple and a 5/8" barbed fitting with 1/2" female adaptor at the water heater for both connections. There should be plenty of pressure in a small service. I'm installing hot & cold for the galley and cockpit shower fixture. The vanity will just have cold.

 

[catalanc]

On a separate note ... just in case you need get another one ...

 

[Blitz]

The instructions also indicate that the tank can be installed in-line after the pump, or it can be installed off-line on a tee after the pump. Since the purpose is to even out the pressure, is there any preference? I guess I'd have to buy a cap for the other end if I install off-line. What is that adapter for? I'm assuming that I need to purchase an adapter for the connection to PEX anyway.

It would be better for winterizing to have it set up so the water flows through the fitting on the accumulator.

2. The Pump instructions indicate that it is preferable to connect a flexible water line within at least 18" of the pump. I am assuming that PEX is NOT considered flexible (or is it?). In that case, I figure that the conduit from the tank to the pump will be a flexible hose. I could start with PEX just past the accumulator, no?

Shut flow has a kit for this, basically 18" flex line like you would use on a house installed before and after the pump.

BTW - I just installed an accumulator and replaced my fresh water pump. The accumulator didn't do much, probably not worth it. I have always found the the hot water heater on the hot water side had a greater accumulator effect then my added accumulator on the cold water side.