Stumped as to why Shurflo water pump wont shutoff

[mbrandt1402]

If the pump is the problem, check out the Aquajet RV pumps. We just upgraded from a Shurflo and it really is a SIGNIFICANT upgrade. Remarkably quiet & powerful.

[Solask]

Fixed it! I went to pull the Shurflo 4008 pump out to see what was going on and it almost fell apart in my hands. Nearly all the screws that mount the top of pump to the pump body were completely backed out. This is why the pump seemed noisier. Tiffin did not make it easy to remove and re-install this pump but it's done. In the picture I took yesterday afternoon, you can see one side pulling up. By the time I got to it today, it was almost apart..

[Skip426]

Question.

Had you done the winterizing on this RV or did you purchase it after it was winterized?
Reason, for the question . If the person who winterized the RV just , blew the lines with compressed air , there may have been some water left in the pump , and as the ice formed , it could have pulled the threads in the plastic housing; even cracked it. Check the pump frequently for leaks and listen for any " burping " when sitting under pressure when not in use.
Your issues with the pump , may not be over.

[Solask]

Originally Posted by Skip426

Question.

Had you done the winterizing on this RV or did you purchase it after it was winterized?
Reason, for the question . If the person who winterized the RV just , blew the lines with compressed air , there may have been some water left in the pump , and as the ice formed , it could have pulled the threads in the plastic housing; even cracked it. Check the pump frequently for leaks and listen for any " burping " when sitting under pressure when not in use.
You issues with the pump , may not be over.

Bought the coach 2 months ago in Fort Worth TX. Dealer sold it new to a local who decided he wanted a diesel 2 years later.
No idea about winterizing. None of the screws were stripped as if they were forced out. They screw into to an aluminum housing. It runs quietly now and shuts off almost immediately after faucet is shut off. Pressure is great and constant.
But, you can bet I'll keep my eye on it.

[Tomp4801]

Nice to see a resolution to the OP original problem. I have a pump problem that I can't quite figure out. I put in a new pump, thinking that would solve it, but I have the same issue.......the pump will run up to full pressure and shut off......that is normal. When I open a faucet, the pressure starts out great, but then quickly runs down to about 50% of where it should be. If there was a loose connection, I would think that I would not be able to build up to full pressure, or it would cycle on and off... Neither of which happens. Any suggestions for trouble shooting this low pump pressure problem would be appreciated..

[Solask]

Originally Posted by Tomp4801

Nice to see a resolution to the OP original problem. I have a pump problem that I can't quite figure out. I put in a new pump, thinking that would solve it, but I have the same issue.......the pump will run up to full pressure and shut off......that is normal. When I open a faucet, the pressure starts out great, but then quickly runs down to about 50% of where it should be. If there was a loose connection, I would think that I would not be able to build up to full pressure, or it cwould cycle on and off... Neither of which happens. Any suggestions for trouble shooting this low pump pressure problem would be appreciated..

Tom, I lucked into my fix but on my previous older coach I had a little pressure tank/bladder. If you've ever had well water in your home, you are familiar with this large blue tank. The purpose was to maintain water pressure during long runs. Do you have one of these? They are normally next to the pump and have air valve on them to check air pressure on the internal bladder. My newer coach didn't have one so I assume the newer pump had some sort of internal device for this.

[Tomp4801]

No, my Shurflo pump is basically on demand. It should be generating a good flow of water at a decent pressure when running, however, it really doesn't. And it's not like I'm running multiple faucets at once....., when I turn on the bathroom faucet it starts out good, but quickly slows down to less than half of the pressure that it should be.

[mbrandt1402]

Could there be a blockage in the supply to the pump?

With what you describe, if given enough time (i.e. running with the faucets closed) the pump develops enough pressure in the line that the initial flow of water is normal. The pump doesn't have enough throughput, so the flow drops dramatically. If the pump is okay (should be since it is new and the problem didn't go away when you installed it), I would examine the supply to the pump for kinks & blockages all the way back to the tank.

[Tomp4801]

With no faucets open, the pump builds up pressure and stops in less than 20 seconds. It is kind of cramped in my water bay but I will do my best to back track the water supply. Thanks

[cb1000rider]

Originally Posted by Tomp4801

No, my Shurflo pump is basically on demand. It should be generating a good flow of water at a decent pressure when running, however, it really doesn't. And it's not like I'm running multiple faucets at once....., when I turn on the bathroom faucet it starts out good, but quickly slows down to less than half of the pressure that it should be.

That sure sounds like a pump or supply problem... I don't know what else it could be if it happens at all faucets. For under $100, I'd start with the pump.

I'm a fan of the 1 gallon (or less) pressure tanks too.. I just haven't gotten around to putting one in, mainly due to a lack of PEX tools.

[Solask]

Hey Tom, 20 seconds to shut off supports the theory that there is a problem between the water tank and the pump. Or the pump is no good (I know it's new).
If there is an issue pulling water from the tank, through it's associated hose, it will still build up enough pressure to eventually make the internal pump pressure switch turn the pump off. Then you turn a faucet on and all that built up pressure quickly declines if there is an issue between the tank and the pump, or the new pump itself. If your problem was with the hoses on the other side of the pump going into the coach, you most likely would have consistently bad pressure.

[Tomp4801]

I agree, It seems to be between the tank and the pump. There are strange hose clamps holding the hoses on. I have never seen them before. They look like they are clamped on, with no way to reuse them. I am going to pick up a length of hose and see if I can run it straight from the tank to the pump, bypassing the winterizing valves and lines to see if that solves the problem. . Here is a pic of the clamps.....anyone know how to open and close them?

[sfi4]

They are called Oetiker Clamps - The bands are sized for the final outside diameter to be clamped to - They are a one-time use clamp
There is a special plier type tool used to properly close the bands

You have to cut the ears on the band to remove them

[Tomp4801]

Thanks. Would you just replace them with standard hose clamps ?