Flow jet pump
- Thread starter John e
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Mel
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On another forum there has been some discussion about how noisy pumps are on Swift Caravans. Our pump is certainly noisy.
The consensus seems to be that it is not the pump that is the problem, but the way it is mounted, causing vibration. Folks suggest using mounting screws with a sort of rubber bung in the middle ( they have a name, someone will know it) as a way of reducing the noise. May be worth considering as much cheaper than a new pump.
Mel
The consensus seems to be that it is not the pump that is the problem, but the way it is mounted, causing vibration. Folks suggest using mounting screws with a sort of rubber bung in the middle ( they have a name, someone will know it) as a way of reducing the noise. May be worth considering as much cheaper than a new pump.
Mel
I replaced re my Flojet pump and I mounted it on a piece of board which used soft rubber mounts screwed into it. The Flojet itself was then mounted on the board using its supplied mounting piece. But I took care not to over tighten the mounts so as not to stiffen them. Inlet and outlet pipes pipes I also fixed using resilient mounts. It improved it quite noticeably. But generally I would question why the caravan maker locates what is acknowledged to be a noisy vibrating pump right under where you sleep without any cognisance of noise reduction measures.
The reason inboard pumps are much noisier than external pumps is the need for the internal pump to be able to produce enough suction to lift water from an lower external water container. The only pumps that can achieve this and still be a practical size and power for caravans are "positive displacement"or diaphragm pumps. This type of pump has to have reciprocating parts , which inevitably makes the pump body vibrate. Caravans need to built with thin wall and floor panels and just like fine musical instruments they can easily amplify the volume of anything that vibrates in contact with it.
There are vibration absorption pads which can mount the pump on to reduce the transmitted vibrations but they will never be completely suppressed with this type of pump.
The alternative approach as used by many caravan manufacturers is to use an external submersible pump which is dropped into the external tank and becasue it is in the water it does not have to create an air vacuum to suck the water into it. You may need to prime the pump after refilling an external tank, but that is usually simply achieved by disconnecting the pump from the side of the caravan when you are about to refill the water tank, and then dropping the pump into the fresh tank before reconnecting it to the caravan.
The submersible pumps are quieter for two reasons, firstly they use a rotating impeller rather than a reciprocation motion, so the pump tends to be much smoother and quieter than the inboard pump, but becasue it is external to the caravan it is almost silent inside the caravan.
It is important not to allow submersible pumps to run dry as that will dramatically reduce their working life, so you need to be vigilant and make sure the tank is kept full enough to prevent this.
If you decide to change to an external pump, you would need to make some changes to the pipework where the old pump was, you would need to fit a water pump inlet fitting to allow the power to get to the pump, and you would almost certainly need a pressure switch. All these items are readily available from caravan dealers.
There are vibration absorption pads which can mount the pump on to reduce the transmitted vibrations but they will never be completely suppressed with this type of pump.
The alternative approach as used by many caravan manufacturers is to use an external submersible pump which is dropped into the external tank and becasue it is in the water it does not have to create an air vacuum to suck the water into it. You may need to prime the pump after refilling an external tank, but that is usually simply achieved by disconnecting the pump from the side of the caravan when you are about to refill the water tank, and then dropping the pump into the fresh tank before reconnecting it to the caravan.
The submersible pumps are quieter for two reasons, firstly they use a rotating impeller rather than a reciprocation motion, so the pump tends to be much smoother and quieter than the inboard pump, but becasue it is external to the caravan it is almost silent inside the caravan.
It is important not to allow submersible pumps to run dry as that will dramatically reduce their working life, so you need to be vigilant and make sure the tank is kept full enough to prevent this.
If you decide to change to an external pump, you would need to make some changes to the pipework where the old pump was, you would need to fit a water pump inlet fitting to allow the power to get to the pump, and you would almost certainly need a pressure switch. All these items are readily available from caravan dealers.
When we had our Abbey caravan our pump was very noisy but it was working if it wasn"t we would get our caravan engineer to sort it for me
The main reason for the on board pump is filling and using the on board water tank in addition to an external source eg aquaroll
.....I have a Swift with an onboard diaphragm pump. Swift basically mounted it directly to what amounts to a sound board that amplifies it's noise.
I changed the mountings to flexible rubber blocks glued to the board and bolted to the pump.(similar to Otherclive)
I then wrapped the whole pump in several layers of bubble wrap held in place with a plastic tie.
I can still hear if it is working but its no longer annoying.
My pump never works unless a tap is opened and this should be the case if the pump and pipework have no leaks or faulty non return valves.
I changed the mountings to flexible rubber blocks glued to the board and bolted to the pump.(similar to Otherclive)
I then wrapped the whole pump in several layers of bubble wrap held in place with a plastic tie.
I can still hear if it is working but its no longer annoying.
My pump never works unless a tap is opened and this should be the case if the pump and pipework have no leaks or faulty non return valves.
I did discuss this with a caravan engineer who was repairing out caravan. He was not aware of a complete answer and the best he could suggest was using a piece of thick carpet under it. The pump runs for so little time though we lived with it and at least it cannot be stolen easily when om site. Unless you are having a shower it is at best a very minor distraction.
I did wonder if moving it over an under floor support brace might help but never tried it.
I did wonder if moving it over an under floor support brace might help but never tried it.
We have an onboard pump for the on board tank, as well as a submersible in the barrel. Last thing at night we always switch over to the submersible to avoid the noisy pump under the bed disturbing us at night.
Not sure about the exact mounting of the pump but did find ‘mechanical vibration damping mounts’ in various formats on Amazon amongst others, so maybe a possible cheap solution.
Here’s a typical Flojet similar to the one I fitted to my caravan. As I posted above I double mounted mine and flexibly mounted the adjacent inlet and outlet pipes. Intersting that the price is now on a par with what I paid, but in summer 2020 as lockdown eased they were as rare as hens teeth and traditional caravan suppliers were asking £115, many though just putting you on an open ended waiting list. I bought mine from a specialist pump supplier.
Flojet 12v Pump for Truma Water Systems in Caravans and Motorhomes
The Flojet 12v 30psi automatic self-priming water pump for Truma water systems. The pump is designed to be fitted inside caravans and motorhomes, fitted with most Truma water systems, supplying a good level of water to taps and showers.
www.jacksonsleisure.com
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Look on the positive side of side of a noisy pump, it’s a good audible warning feature if your plumbing has a leak…….
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