Pump not stopping (Shureflo)

[the1andonly]

First try out and refill since march freeze.
Push in frost button
close drain taps
fill with water taps on 12v off
close taps
Pump on, and stays on no pressure built up.
change filter cap and filter no change
prime filter bowl no change
use another 3rd cap and filter no change ( note body not changed).
try spare pump ( not mounted in position) no change
strip spare and investigate return valve ok no crud in way rebuild no change
check both inspection caps tight , yep.
No obvious air or water leaks from acessable /vissible stuff.
To note
Gurgling from boiler corner under sink.
I have not investigated possible leaks in boiler area as it is totally encased by cupboards with no access at all. A Rapido owner on faceache had to totally dismantle kitchen for access. Some models have an outside door for access, mine doesn't. The only way i can see of getting access is to cut out big inspection panels inside 2 cupboards not knowing orientation of Truma in the corner makes it difficult to chose which to cut and is it safe to attack it with a jigsaw (obviously fitted before the walls.)

So What else can i try short of dismantling kitchen.
with exhaust on rhs at rear where is pipework likely to be. should i try acess from behind exhaust or left of exhaust (ie towards front of van)
PS its a Coachbuilt Rapido Truma 6

 

[Lenny HB]

It's probably the air relief valve in the Tee piece where the hot feed out connects to the boiler. A common problem you should see water running out under the van from a pipe below the boiler.

I know Rapido are experts at making the boiler inaccessible but I would have thought there would be access to that valve.

 

[the1andonly]

Lenny thanks for prompt reply
found a drain pipe imedeatly under flue , but dry as a bone.
I suspect theres a few gold cups engraved with manufacturers award for pissing off customers in Rapido headquarters..
Any another clues?

 

[AdrianChen]

If there is no water appearing from under the van as Lenny mentioned, or inside then I guess the pump is sucking air in on the feed side - it would keep running because there would be no pressure - I would check every connection from the tank - if push fit types then give them a push to be sure they're fully home, and double check the O ring is seated properly in the little clear strainer. Spent hours once looking for leaks etc, only to find I had pinched that O ring.....

 

[the1andonly]

If there is no water appearing from under the van as Lenny mentioned, or inside then I guess the pump is sucking air in on the feed side Spent hours once looking for leaks etc, only to find I had pinched that O ring.....

Already spent hours but many more before going away on 16th.
which is feed side , filter or non filter.
as i ask i can see the reply look at pump theres a bloody big arrow. so off to check for arrow.

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[Carpmart]

Sadly you’ll have to persevere…. I know you can’t get to the boiler easily, but can you check the vicinity for water?

Have you definitely got water flowing through the pump? If you have, it has to be going somewhere.

Keep looking and good luck!

 

[AdrianChen]

direction of flow should be from tank through the little strainer then into the pump. Good luck with it - it needs only a tiny hole for enough air to get in and stop the upmp from priming.

 

[the1andonly]

Arrow checked and been playing with it since last post so thanks for encouragement.
I think ive found the problem.
Got under van with pump on and listened to drain tap, been playing with it and now pump stops, air leaking in from the drain system. In trying to flush it out i thought main drain (grey) was slow the red (20l level) was running as it should. So interim measure leave grey open and a JG tap underneath. Time to put old new pump back into service.
Thanks for all the assistance and words of encouragement

 

[LesW]

I had a similar problem to this on our Inca (2004).

I fitted a one way valve to the water pipe just before where it enters the pump, meaning that the water couldn't drain back to the tank.

That cured my issue.

 

[the1andonly]

Lots of little oportunities to screw it up.

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[Dorwyn]

I can't follow all this info but I once had something like this on a Truma and it was the auto frost protection dump valve open. I am sure you are much cleverer than I but I just wondered.

 

[Cobra]

I had the same last week
It turned out to be a crack on the inlet filter
You couldn’t see it until the filter was unscrewed and removed
Replaced the filter bowl and all is well With the pump
unfortunately the water filter had a freeze crack too which meant, when I fixed the pump, it pured water everywhere!

Andy

 

[the1andonly]

to sum up the problems/solution
this type of problem can be as a result of problems in two places
1 After pump
dump valve
air relief valve in the Tee piece where the hot feed out connects to the boiler.
Both these use up water and dump to floor.
2 inlet to pump
filter cap cracking
filter cap seal ring badly fitting
filter mesh blocked with fine slime
push fit connectors loose
drain valve sticking/ air leaking
any other variation on air being sucked in caps in water tank inlet pipes.

 

[IRHP]

Not sure what you are saying but you say taps off, do you mean closed, if so and you have air in the system the pump won't stop as it's trying to compress air. Open taps , hot and cold and let them spit and splutter until water runs free. Then close them and the pump should stop

 

[the1andonly]

I don't think you quite understand how the Sureflo system works. Its whole premise is to pressurize the tank. When working properly the system is slightly pressurerised and when you open the tap the presure pushes out water when the pressure drops bellow a set value the pump kicks in and water continues to flow. When you close the tap the pump continues untill the required pressure is built up. IF pressure cant be achieved that's when you have a problem and with an air leak the pump will continue to run.
The best way to create an air lock free system is to fill with pump off, taps open.

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[Reallyretired]

If your Rapido has that big drawer thing under the sink, then removing that by releasing catches on the runners does give a bit of boiler access, however it sounds like your problem is a lack of priming rather than the boiler.

 

[L' Hobo]

I don't think you quite understand how the Sureflo system works. Its whole premise is to pressurize the tank. When working properly the system is slightly pressurerised and when you open the tap the presure pushes out water when the pressure drops bellow a set value the pump kicks in and water continues to flow. When you close the tap the pump continues untill the required pressure is built up. IF pressure cant be achieved that's when you have a problem and with an air leak the pump will continue to run.
The best way to create an air lock free system is to fill with pump off, taps open.

Maybe, I have similar to IRHP because,

On mine, it doesn't pressurise the tank, just the pipe system after the pump (the pressure switch is part of the Shurflo pump).

Have you got a different type of system?

 

[Lenny HB]

Maybe, I have similar to IRHP because,

On mine, it doesn't pressurise the tank, just the pipe system after the pump (the pressure switch is part of the Shurflo pump).

Have you got a different type of system?

You are correct he has that bit wrong.
The tank has to have an air vent to allow water to flow out.

 

[Lenny HB]

I had the problem once of no water coming out & the pump continuously running. It just wasn't drawing up water probably an air lock. Sorted by opening all the taps just a tiny bit and after 10 min it sorted itself out.

 

[funflair]

I had the problem once of no water coming out & the pump continuously running. It just wasn't drawing up water probably an air lock. Sorted by opening all the taps just a tiny bit and after 10 min it sorted itself out.

That's a fair point Lenny and possibly not everybody realises that the pump will not prime itself if the taps are closed as it just bounces off the air in the pipes and can't move water through.

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[Trevor Wbm]

At the beginning of this year I found that to stop the pump pulling air from joints, I had to use a spanner rather than a screwdriver on the jubilee clips. I assume the vibrations from the vehicle moving slowly but steadily loosens them off.

.. and definitely all taps and shower open until they run properly. It always takes more water and time than I'm expecting.

 

[the1andonly]

Well gents
i have got it wrong the tank is not pressurised,
i must have had strange problems in past as it wouldnt run without tank cap closed. it does now. i had to redo the overflo a while back (years?) since the overflow pipe looped over the top of the tank (only acting as a breather). when too full water used to come out of the tank cap over the floor. (ive fitted a new overflow/breather and blanked of old one Another example of Rapido being less than perfect.
So don't believe me my system is/was different to everybody else.

 

[the1andonly]

If your Rapido has that big drawer thing under the sink, then removing that by releasing catches on the runners does give a bit of boiler access, however it sounds like your problem is a lack of priming rather than the boiler.

Luckily its not the boiler.
My sink is smack bang in the corner.
Removing the big drawers on either side gives no access to boiler, its blocked by cupboard sides. Ive always wondered witch side i would need to cut an access hole in. where are the water feeds likely to be ? Any photos of a Rapido boiler fitting could be usefull.

 

[IRHP]

I don't think you quite understand how the Sureflo system works. Its whole premise is to pressurize the tank. When working properly the system is slightly pressurerised and when you open the tap the presure pushes out water when the pressure drops bellow a set value the pump kicks in and water continues to flow. When you close the tap the pump continues untill the required pressure is built up. IF pressure cant be achieved that's when you have a problem and with an air leak the pump will continue to run.
The best way to create an air lock free system is to fill with pump off, taps open.

I'm sure I do know, the tank isn't pressurised but the pipework is.

 

[the1andonly]

I'm sure I do know, the tank isn't pressurised but the pipework is.

see my reply #22

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