45-DS: Insufficient flow at transom/deck shower

[jeremyr]

2009 Jeanneau 45-DS with original Plastimo stern deck shower including hot-cold mix/flow valve. We are getting so little water out that it doesn't even form a spray pattern. I have not measured carefully but it appears to be well under 1 gpm. If I disconnect the shower hose the flow is only slightly better at the the output of the mix valve. I disconnected the mix valve and blew through it and it appears to be clear and operating properly. Results are similar on both hot and cold, suggesting that it is not a simple kinked line.  The flow of both hot and cold appears fine at the sinks and head showers, so the pump pressure flow appears to be reasonable.  I have not yet measured things at various points (takes two people; one to hold a bucket by the disconnected line and the other to turn the pump breaker on/off when asked), but am wondering if there is a known issue I should consider first. Also, does anyone know what the specs should be on pressure and flow at the connection point of the shower mixer valve in order to get acceptable performance?

[rene460]

Hi Jeremyr,

I assume that the pump starts and stops when you run the transom shower as it does when you just partly open a tap at the sink or basin.  This indicates that the pump is supplying more than is flowing through the shower.  As you have two pipes to the shower mixer valve from other points in your water system, an equal or similar blockage in both hot and cold pipes but not affecting other outlets seems unlikely.  If the flow does not increase when you unscrew the shower head, then the mixer valve still seems suspect.  However it would be useful to switch on the pump with both lines disconnected at the inlet to the mixer valve when you have a helper.  It is difficult to estimate the pressure and flow of air when you blow that would be equivalent to the normal water flow due to the difference in density of air and water, but blowing through the shower fitting might provide a useful comparison.  Is the tap one that you can disassemble, or is it the throw away plastic type?  The one supplied with my caravan recently allowed very little water flow in any tap position and mostly cold even when turned fully to the hot position and had to be replaced.

rene460

[alex1949]

Hi Jeremyr,

Sometime problems like that are rather easy to solve, please check if the outgoing pipe (The one you pull if want to use) is not twisted around to much so it block the soft hose. Pulling out and back result sometimes in such a knot like blockage of the hose.

Please be sure your hose is free before getting involved in more complicated actions.

Alex

[jeremyr]

Than you Rene460 for your thoughtful comments. Yes, the pump cycles on and off. The flow varies slightly with the cycling as the pressure builds and fades, but is always on what appears to be the low side. Again, I will check/measure more carefully when I get a helper.  The mixer valve is a Plastimo 45602 which rotates for hot/cold and tilts for on/off. After the shower spray handle and its hose, the mixer's the prime suspect. I agree that it is hard to judge water flow resistance by blowing, so I will head down to the boat with a bucket with markings and an assistant before jumping to any conclusions.

www.downwindmarine.com/Plastimo-Deck-Shower-amp-Mixer-Tap-Sets-p-91000936.html

So, either I have some sort of flow restriction (e.g. at the mixer valve) or perhaps my system is set at too low a pressure for the size/length of the piping, or perhaps all the pressures/flows are fine and the sprayer is just a piece of junk and replacing it with a better one will give me a nice spray instead of something that looks like it's slowly coming out of a badly maintained public drinking fountain.

I will report back after measurements. In the meantime feel free to offer any observations from other similarly equipped Jeanneaus.

Thx

P.S. 
To alex1949: Thanks but I ruled those issues out already. My original post mentions that, "If I disconnect the shower hose the flow is only slightly better at the the output of the mix valve." That's before the shower hose.

[MalcolmP]

Whilst I can't add to the fault finding issue, I thought I would just add a reminder that plastic shower heads are quite brittle and will often crack at the thread if left in-situ in freezing conditions, as part of my winterization I remove the shower head and block the pipe with a domestic radiator valve blank (which in the UK at least) has the same thread.  On our 2008 boat the deck shower is the same design as on the 2009 45DS and is still working well - touch wood