Community Forums

acraig · 08-31-2018, 02:37 PM

I recently purchased a 2015 Canyon Star 3921. Its previous owner was located in the midwest. We are only getting about 1 gallon per minute (gpm) water flow to all water outlets (kitchen sink/bathroom sink/shower). This is the case whether connected to city water or just using the onboard Flojet pump which is rated at 2.9gpm. If the low volume was evident when just using the pump, I would suspect a pump failure. However, city water connection is the same which would indicate a problem in the plumbing common to both pump and city water connection.

The low flow is actually quite a water saver, but problem is that it doesn't allow the Atwood tankless water heater to function properly: the water heater needs more flow to keep firing when we try to regulate the water temperature to something less than scalding hot with our single handle faucets. Particularly a problem in the shower and temperature fluctuates from hot to cold and vice versa. So far, have been unable to find what is restricting the flow. Next step is to try to gently blow out the lines with compressed air in hopes of dislodging something (perhaps sediment from midwest water source or calcium buildup?). From water system drawings, the system is not terribly complicated and there are only a few check valves inline.

Looking for additional ideas before I take it to the dealer for further sleuthing. Has anyone else experienced a similar problem?

By the way, if I had purchased the coach new, I would have gone with a traditional tank heater and a non-residential refrigerator!

Thanks for your thoughts.

A Craig
2015 Canyon Star 3921

BFlinn181 · 08-31-2018, 02:47 PM

Look for a water filter in the line that might restrict flow. Most RVs have a strainer in the line between the water tank and the water pump, make sure it has no debris in it. Have you removed and cleaned the aerators at each faucet? I don't think air will dislodge any deposits, you could use white vinegar. With the water tank mostly empty, pour a couple of gallons into the tank and run it until you smell it at each faucet. Then let it sit overnight and flush it all out. Do this with aerators and showerheads not connected.

acraig · 08-31-2018, 02:57 PM

Yes, have removed and cleaned all aerators. Interestingly, there is no strainer installed between the water tank and the pump even though the Flojet materials say that the pump warranty is voided without the strainer. I have looked at other Canyon Stars, same situation: no strainer. Our local Newmar dealer tries to explain that away and say it's not necessary. I just purchased a Flojet strainer and intend to install.

The vinegar treatment is on the to do list.

GaryKD · 08-31-2018, 04:44 PM

Hi,
I know you said it happens with shore and pump. However, just for laughs, remove the whole house water filter. Usually found in the utility bay. See what happens. Nothing to loose.

acraig · 08-31-2018, 05:21 PM

Thanks, should have mentioned I have previously done that. No change in flow.

As you are seeing, nearly all the likely suspects have been ruled out. The problem seems to be hiding out in an inaccessible place.

WoodyS · 08-31-2018, 11:53 PM

1) This won't change city water pressure, but there IS a filter/strainer on the water pump. It's attached to the pump itself -- not an inline filter between the pump and pipes. They can gum up with algae -- particularly if the rig has been sitting for a length of time. A good sanitizing might also clean out this filter. That worked on one of my RVs in the past. But again, this won't change water flow when you're using the city hookup.

2) When you look into the city water hookup fitting in your wet bay, can you see a SS mesh screen? You can buy washers with built-in SS mesh screens and a previous owner might have installed one. If so, remove it and replace with a regular washer and see if that makes any difference. But since you say pressure is the same with the water pump -- that pretty much eliminates this situation.

3) Calcium carbonate build-up "usually" only happens in the water heater. So if you have calcium carbonate mineral deposits, they "shouldn't" involve the cold water system. But it sounds as if you have low pressure on everything.

4) One gallon per hour is really really low. It sure sounds like there's a clogged filter somewhere. And the fact that it's the same with city water and water pump, tells me the blockage is in a shared component -- shared by both the coach's water tank and water pump and city water. So that means the blockage is AFTER the water pump and after the city water system.

5) Have you "played with" the winterization valves? Perhaps one or both of them are either set incorrectly, or there's a blockage.

6) Have you opened and looked in the house water filter housing? I'm thinking there's some kind of blockage in there. Have you completely removed the filter and operated the system with no filter at all in there?

acraig · 09-01-2018, 11:07 AM

Woody, thanks for all your thoughts.

1) I did clean the filter that is incorporated in the water pump. It was quite dirty, but no effect on flow.

2) City water hookup inlet doesn't appear to be impeded, but I'll be checking again.

3) Low flow is consistent with both hot and cold water.

4) Flow is 1 gallon per minute (should be between 2 and 3). Agree that something is amiss in a shared part of the system.

5) Will keep toggling all valves that I can touch.

6) Water filter has been removed and system operated without it. No change.

Will keep investigating!

WoodyS · 09-01-2018, 02:36 PM

Try running some sanitizer through your entire system. Let it soak good and long. Make sure the sanitizer gets in all the pipes and valves. Then see if there's an improvement.

When a fresh water system sits for a long time, "stuff" grows. In many cases sanitizing not only kills the algae and other stuff, but completely removes it. Years ago I had this happen in our Chinook. City water flow was fine, but not through the water pump. I figured the filter on the pump motor was clogged, but it's hard to get at in that rig. So I sanitized. And that cleaned out the filter and I didn't even need to replace it.