Flojet not working

[otherclive]

Brought the caravan out of store for a trip away but I’m having problems with filling the water system for sterilising. . Initially the Flojet pump started up fine and water started to flow from the taps. Then it went dead. I moved the tap heads (3 ) thinking it might be a micro switch but pump still dead. Toilet flush ok which comes off same fuse. Anyway I removed the fuse and cleaned it but it was fine. So then disconnected the two pump supply wires and checked for voltage which was there. Pump has been removed now to see if it has any internal stiction or anything preventing rotation. I also removed the bottom electrical cover and checked the two spade connectors but they were clean and tight. If that is fine what other things should I look for. Never had a Flojet before.
Picture below:

 

[ProfJohnL]

I'm not familar with the details of Flowjet pumps, but :-

The picture you have posted gives a part number of R3426504, and whilst I can find people selling them, they don't list the specification, but the design of the pump seems to be a Flojet Triplex series, and other current models with the rectangular box on the end of the pump housing are all listed as having a pressure switch built into them. The pumps are also listed as having a 3M self priming capacity, which points to them being positive displacement pumps very much like Shureflow pumps.

These pumps are capable of producing very high outlet pressures (Enough to blow a caravans watrer system) so the fact its data lable gives a pressure range of 2.01Bar maximum tells me you pump has a built in pressure switch.

If the pump is not running when power is supplied to the switches input wires, then i'd be checking if power directly to the motor (bypassing the pressure switch) worked or not.

The Shureflow pumps were quite current hungry to get going. I would strongly recommend ensuring you have a battery connected and not just relying on the caravans 230 to 12v power supply.

 

[otherclive]

Thanks Prof. The pump is now running and the pressure switch is on the base but pump has to be removed to access it. I’ve taken off the cover and pressed its input a few times. Replaced the switch and reinstalled the pump. It now runs but isn’t delivering any real output. I’ve bled the inlet pipe a few times to make sure there’s no airlock. Can’t find an NRV in the inlet to the pump. Wouldn’t necessarily expect one on a diaphragm pump.
So the sytem works electrically but no real output. Suspect pump is US. They are rare as hens teeth at moment. Swindon Caravans have a batch in order expected later this week. So I’ve ordered one from a marine parts supplier which should be here Thursday. Many caravan suppliers are stock out or 8-10 day delivery. We are booked to depart Thursday so if it arrives I will be doing a bit of plumbing Thursday evening. That assumes my new drive shaft is fitted okay tomorrow. I thought this hobby was meant to be restful.

 

[ProfJohnL]

If you cant get a Flojet then there are models from both Whale and Shurflow that should substitute quite satisfactorily. Just make sure the pressure setting does not exceed 2.0Bar.

 

[otherclive]

If you cant get a Flojet then there are models from both Whale and Shurflow that should substitute quite satisfactorily. Just make sure the pressure setting does not exceed 2.0Bar.

I’ve sourced an on line 48 delivery of the correct pump. £59 inc pp. I have sourced two at caravan dealerships near Salisbury. £115. 😬 I really want to avoid having to make any pipe work changes to accommodate a different make of pump. Screwed up at the front of the front locker isn’t much fun fir a 6ft 4 in over 70 inside a hot caravan.

 

[JTQ]

The Flojet pumps are "diaphragm" pumps some four chambers and each chamber will feature NRVs at the inlet to and outlet from those chambers.
These pumps generically are very prone to debris screwing up the functioning in part or fully of the NRVs. Because they are lift pumps they can't tolerate inlet filtration as such only a strainer, typically a stainless steel wire mesh, but one that passes broken off spiders legs for example.

If the van has been laid up then such things as departed spiders, the dried out remains of their meals and hardness flakes from inside the inlet tube are all waiting to be flushed into the strainer and some remnants not retained by that into the NRVs.

Any number of times I have pulled the similar Sureflo and Whale versions apart to clean up the NRVs; I even once purchased a service kit but never found the need to use its bits, I cleaned the NRVs and all was good again for a couple of years.

I would be pulling it apart long before spending on a replacement, but it is something I am confident and skilled enough to do, though I don't regard doing so challenging, just it needs some care.

These people simply found by Googling are venders of spares, but from my experience these are unlikely to be required;

Flojet Pumps Spare Parts Repair Kits and Service Kits

Flojet Pumps Spare Parts, Replacement Spare Parts, Repair Kits, Service Kits. Diaphragm Kits in BUNA, EPDM, Santoprene and VITON, Valve Chamber Kits, Check Valves, End Caps and Pressure Switches for all Flojet Diaphragm Pumps.

www.allpumpsdirect.co.uk

 

[otherclive]

The Flojet pumps are "diaphragm" pumps some four chambers and each chamber will feature NRVs at the inlet to and outlet from those chambers.
These pumps generically are very prone to debris screwing up the functioning in part or fully of the NRVs. Because they are lift pumps they can't tolerate inlet filtration as such only a strainer, typically a stainless steel wire mesh, but one that passes broken off spiders legs for example.

If the van has been laid up then such things as departed spiders, the dried out remains of their meals and hardness flakes from inside the inlet tube are all waiting to be flushed into the strainer and some remnants not retained by that into the NRVs.

Any number of times I have pulled the similar Sureflo and Whale versions apart to clean up the NRVs; I even once purchased a service kit but never found the need to use its bits, I cleaned the NRVs and all was good again for a couple of years.

I would be pulling it apart long before spending on a replacement, but it is something I am confident and skilled enough to do, though I don't regard doing so challenging, just it needs some care.

These people simply found by Googling are venders of spares, but from my experience these are unlikely to be required;

Flojet Pumps Spare Parts Repair Kits and Service Kits

Flojet Pumps Spare Parts, Replacement Spare Parts, Repair Kits, Service Kits. Diaphragm Kits in BUNA, EPDM, Santoprene and VITON, Valve Chamber Kits, Check Valves, End Caps and Pressure Switches for all Flojet Diaphragm Pumps.

www.allpumpsdirect.co.uk

Thanks I looked at their site in case I felt a pressure switch was required but they cost nearly 50 % of the cost of a complete new pump assembly. It has all of the hallmarks of a NRV problem as I hear water gurgling at the sink tap but it just doesn’t have enough behind it to flow out of the tap.

 

[JTQ]

It has all of the hallmarks of a NRV problem as I hear water gurgling at the sink tap but it just doesn’t have enough behind it to flow out of the tap.

Clive, if my many years of experience with Diaphragm pumps of this ilk are any guide then it will be as I described simply leaky NRVs. In all other regards these are excellent pumps and my experience otherwise bullet proof. You just have to expect to occassionally go into them and clean them, usually this falls as explained within a day of the start of the season!

 

[otherclive]

JTG
I have stripped it down to the valves and whilst there was some staining on the polymer support plate the internals were remarkably clean. I washed it in warm water and used a soft brush on the diaphragms then rinsed it. I looked at the diaphragms to see if I could see a split or anything that would lead to leak back and reduced output pressure/ flow but could not see anything. Reassembly was straightforward and on powering up the net result was no change. I’m beginning to wonder if the motor might be down on output but have drawn stumps for the evening. New drive shaft tomorrow so if the replacement pump isn’t here on Thursday it could be a grungy few days or risk facilities.
Thanks for the advice. Good site here for a Flojet shows and identifies the parts. Problem is I don’t know what the problem is ☹️

https://www.xylem.com/siteassets/brand/flojet/resources/brochure/r3426_81000-384.pdf

 

[JTQ]

Clive; it could also raise the question if the inlet has issues like strangulation or a minor air leak? The latter would decimate the achieved flow, easily killing it if more than very small. Is the strainer clean enough?

If the diaphagm(s) were pierced then there would be water were it should not be, so that would be evident enough.

If the rotor speed was down that would inhibit the flow for sure, but not involve any gurggling noises. An air leak would or blowing back through the NRVs. Rotor speed could also be lost if the wiring has a high resistance joint, as I think it will only be a basic brushed DC motor, at this price point?

I await with interest to know how it pans out.

 

[otherclive]

Clive; it could also raise the question if the inlet has issues like strangulation or a minor air leak? The latter would decimate the achieved flow, easily killing it if more than very small. Is the strainer clean enough?

If the diaphagm(s) were pierced then there would be water were it should not be, so that would be evident enough.

If the rotor speed was down that would inhibit the flow for sure, but not involve any gurggling noises. An air leak would or blowing back through the NRVs. Rotor speed could also be lost if the wiring has a high resistance joint, as I think it will only be a basic brushed DC motor, at this price point?

I await with interest to know how it pans out.

JTQ

Pipework is quite kink free from the caravan inlet. I opened up the inlet flexible hose to ensure that it was tight in the handgrip “pistol” it was fine as was the strainer. The two O rings on the pistol were 100% okay. They are are regularly lubricated with silicon lub. When it was running and gurgling I couldn’t see any sign of a leak. It ran fine in February as I had the van back to check it out as it was going for sale. After draining down I pumped through a non toxic anti freeze and drained again. So I don’t think it suffered any frost damage as residual fluid would have anti freeze solution.

Intriguing. In the mags it’s all so straightforward.

 

[JTQ]

The gurgling is inducing leaks that are pulling in air so you would not necessarily see any water leaking, it may well not leak water.

As a test can you contrive to replace the inlet hose with one hose straight into a bucket or bowl of water? Doing so will step over issues from several "joints" that potentially could draw air. That should prove if it is the pump and onwards or the inlet system that is inhibiting the expected flow.


Edit: the bucket I was thinking would be inboard near the pump to make it all practical with minimum effort. I would avoid installing the strainer if that is practical in case that is the source of any air leakage.

 

[otherclive]

The gurgling is inducing leaks that are pulling in air so you would not necessarily see any water leaking, it may well not leak water.

As a test can you contrive to replace the inlet hose with one hose straight into a bucket or bowl of water? Doing so will step over issues from several "joints" that potentially could draw air. That should prove if it is the pump and onwards or the inlet system that is inhibiting the expected flow.


Edit: the bucket I was thinking would be inboard near the pump to make it all practical with minimum effort. I would avoid installing the strainer if that is practical in case that is the source of any air leakage.

That’s what I would do the JG couplings make disconnection quite easy.

 

[otherclive]

New pump has arrived 10 minutes later it was installed and doing its best to rival a Karcher! Still don’t know what caused the old one to fail but we now have running water.
I bought it from an eBay supplier TF Pumps direct who was recommended on a boating website. It was half the price of caravan dealerships and whilst caravan parts suppliers were in a similar albeit slightly higher price bracket they weren’t taking phone orders and best delivery was 6-8 days AFTER they received it from their supplier.

Now all we have to do is reshuffle payload and car load as granddaughter has just announced a no show. Her Dads unexpectedly arrived back from Holland. I must thrive on uncertainty 😁



Worked a treat on site and I think I may use the shower for the first time in this van. Did not manage to sterilise the system so as tomorrow is “ mask” day so should I wear a mask in the shower to prevent Leigionairres. ??? 😹

 

[ProfJohnL]

Good news 😎

 

[JTQ]

Worked a treat on site and I think I may use the shower for the first time in this van. Did not manage to sterilise the system so as tomorrow is “ mask” day so should I wear a mask in the shower to prevent Leigionairres. ??

Well, don't whatever you do shower with 70 C water directly , but if the boiler has the feature to elevated the boiler up to that [as Alde] then that will sort any legionnaires bacteria out.
Though realistically unless you have been keeping the water system “warm” for extended periods then there is minimal chance of any there to kill.

Great to know you are sorted, but irritating not to know the cause of the other pumps problem.

 

[otherclive]

Well, don't whatever you do shower with 70 C water directly , but if the boiler has the feature to elevated the boiler up to that [as Alde] then that will sort any legionnaires bacteria out.
Though realistically unless you have been keeping the water system “warm” for extended periods then there is minimal chance of any there to kill.

Great to know you are sorted, but irritating not to know the cause of the other pumps problem.

Im afraid put the bit in about legionnaires a bit tongue in cheek as there was a discussion a month or so back.
Like you I would have liked to have known what caused the old pump to fail but seeing how the new one performs it was probably starting to go sometime back. An old ticker perhaps. Like it’s owner.