20 replies to this topic

[esimmers]

It sounds to me that there's a flow restriction somewhere in the hot water line. Here's what I'd do to check. First understand how the water system works. The pump draws water from the tank and pumps it to a tee. One side of the tee is sends cold water to the sink and then to the shower; the other side of the tee sends water to the hot water heater. The output of the hot water heater also goes to the sink and then to the shower. Since there's no pressure tank in the system, the pump normally runs almost constantly when either hot or cold water is being drawn from the sink or shower. Yes, sometimes the pump cycles when you're drawing only a little water but the pump doesn't develop enough pressure in the lines when water's being drawn to stay off more than a few seconds before the pressure in the lines drops and the pump has to turn on again.

 

First test to see if the cold water pressure and the hot water pressure are equal at the sink (they should be). Turn off the outside shower. In the sink, time how long it takes to fill a container using only cold water; repeat with only hot water. The flow rate should be the same, if not, there's something plugging the slower one (probably the hot, from your description). There are valves in the hot water line between the pump and the hot water heater in some campers that are used to close off the hot water system in cold weather. Check to see if the valves may be defective.

 

If that test shows pressure at the sink to be the same, repeat the same test with the shower, first the cold and then the hot. If the flow rate's different, then there's a restriction in the line after where the hot water splits off to go to the shower instead of the sink.

 

It sounds like your shower hot water has pressure for several seconds without the need of the pump. This tells me that you're not getting a normal flow rate of hot water allowing the hot water to retain pressure for longer than normal and longer than the cold water. So then when the pump kicks on, the more freely-flowing cold water overwhelms the more-restricted hot water and chills you.

 

Let us know what the test results are.

[camelracer]

I've had problems with the crud from the anode in the water heater plugging the faucet. 

[Grays_and_Shadow]

It sounds to me that there's a flow restriction somewhere in the hot water line. Here's what I'd do to check. First understand how the water system works. The pump draws water from the tank and pumps it to a tee. One side of the tee is sends cold water to the sink and then to the shower; the other side of the tee sends water to the hot water heater. The output of the hot water heater also goes to the sink and then to the shower. Since there's no pressure tank in the system, the pump normally runs almost constantly when either hot or cold water is being drawn from the sink or shower. Yes, sometimes the pump cycles when you're drawing only a little water but the pump doesn't develop enough pressure in the lines when water's being drawn to stay off more than a few seconds before the pressure in the lines drops and the pump has to turn on again.

 

First test to see if the cold water pressure and the hot water pressure are equal at the sink (they should be). Turn off the outside shower. In the sink, time how long it takes to fill a container using only cold water; repeat with only hot water. The flow rate should be the same, if not, there's something plugging the slower one (probably the hot, from your description). There are valves in the hot water line between the pump and the hot water heater in some campers that are used to close off the hot water system in cold weather. Check to see if the valves may be defective.

 

If that test shows pressure at the sink to be the same, repeat the same test with the shower, first the cold and then the hot. If the flow rate's different, then there's a restriction in the line after where the hot water splits off to go to the shower instead of the sink.

 

It sounds like your shower hot water has pressure for several seconds without the need of the pump. This tells me that you're not getting a normal flow rate of hot water allowing the hot water to retain pressure for longer than normal and longer than the cold water. So then when the pump kicks on, the more freely-flowing cold water overwhelms the more-restricted hot water and chills you.

 

Let us know what the test results are.

Thanks for your suggestion.  We are going try your water pressure test as soon as we have time.  If we find that there is a difference in water pressure between the hot and cold water,  we are not sure what we are going to do about it.  There are only two valves in the set-up, a back-flow valve and a hot-water tank by-pass valve.  Just looking at the way this system was designed, to fit in the small space of the camper, it seems obvious that the hot water would not be able to maintain the same pressure as the cold water because the cold water has a shorter "trip" to the outlets, where as the hot water has a longer path.  Does that make sense?

[JHa6av8r]

Could air be getting into the system?  Has the water system been drained completely, refilled, and reprimed?  I think when the pump comes on, it creates and air gap and cold water fills to void.

[Grays_and_Shadow]

Thanks for all the ideas and suggestions.  This is very frustrating to us and all of your support is very appreciated.

 

I tried the water pressure test as per esimmers suggestion. At the sink, it took 15 seconds to fill a 2 qt. container with just the cold.  It took 15 seconds to fill it with just the hot.  The pump was running continuously both times.

 

At the shower, it took 1 minute to fill the 2 qt. container with just the hot, and 1 minute to fill it with just the cold.  The pump cycles 2 seconds on, 3 seconds off, 2 on, 3 off, etc. the whole time, hot or cold. Or both.  When the pump is on, we get warm water, when it shuts off, after about a 1 sec. delay, it is just cold.  Then it is warm again when the pump comes on.  Over and over again.  In my mind this points to a pressure problem.  We have no issue with temperature control at the sink.  One of the things I don't understand is why there is only 1/4 of the water pressure at the shower as compared to the sink.  Is there a reducer type device at the mixer, just behind the quick connect piece?  If so, why?  I may have my reducer/mixer terms misused, but you know what I mean.  If the water pressure was the same at the shower as at the sink, wouldn't the pump stay on and problem solved?

 

I'm not sure if air in the system is the problem, as the sink works fine.  I know I'm missing something though.

[chris@rmfwc.com]

Sounds like the factory is starting to make some progress on this issue. 

 

Part of why I wanted you to relay your frustrations with the factory is so they heard your side directly from you.  I have a critical eye for everything and didn't want them to think Chris was just complaing about somethign again.

 

It does sound like the reduced flow at the shower mixer creates a cycling in the pump.  I.e. the pump does not have to work as hard since its moving less water.  As compared to the sink faucet where the pump just runs constantly with a greater volume of water.  That pump cycling seems to be the key to fixing this issue as well as FWC just being able to replicate the issue on their own factory floor to investigate for themselves. 

 

Just wanted to touch base with you to let you know we are trying to solve this issue.  And I am still willing to try the anti-scald device if it comes to that just to see if that will better regulate the pressure issue.

 

Thanks again for your patience.

 

Best,

 

Rocky Mountain Four Wheel Campers

5415 West 59^th Ave – Unit - E

Arvada, CO 80003

303-431-6611

[bsharp007]

Why is a customer with a brand new camper under warranty problem solving this issue? Shouldn't that be the dealer in his areas job?  Where's their mechanical support, he should have someone with the specific expertise looking at this in the area.

This is a weakness with the FWC product I have noticed even at the factory, sure they will fix some components under warranty it's just getting to the factory. My campers a year old and they forgot intall diamond platting in the forward area. I didn't notice until I got home and when I called it to the attention of the saleman after he got done scolding me they offered to install it. At the factory that is a full six hours away and at least a day or two wasted. Never had the time.

Edited by bsharp007, 11 June 2014 - 03:15 PM.

[KILR0Y]

Diamond plating? Please do tell... that would be a good addition to my camper!

[bsharp007]

Yes it would have, if they had installed it like they said they would. I meant to send a personal email to owner of FWC, just never got around to it. Anyway I didn't mean to hyjack this thread. The owner with the brand new camper should be able to go to his local "dealer" and let them problem solve this issue.

The "dealer" advises "patience", how about getting it fixed and if he doesn't have the expertise send him to a local RV shop who does.

It's called good service, I drove 6 hours to get my refrigertor serviced under warrranty as there were no Norcold service centers in the entire SF bar area. This was a refrigerator a couple of months old under warranty. Several trips later, 6 hours and waiting all day, all this in a camper 6 months old I finally had a refrigerator that worked for about a year. I put off driving to their factory for the diamond plating just didn't have the time or desire especially after the sales person gave me some attitude. I also problem solved and replaced the battery/water level in a 2 day old camper. In other words it never worked from day one and they probably never checked it before I drove away.

Hopefully people can learn from my mistake (and FWC's) check everything before you drive away.

[K-Os]

No problems with shower thus far with 4 big trips under our belt.

Hawk 2014.