Morning Kath,
Please can you check my pump while the caravan is with yourselves at the factory. Discover has had a check of this but could find no problem. We have not been away in the van since so cannot confirm, but the problem we had was with the pump over running and also this pulsating problem. The flow adjustment screw is against the floor so no access is given to adjust.
Thanks
Andy
Please can you check my pump while the caravan is with yourselves at the factory. Discover has had a check of this but could find no problem. We have not been away in the van since so cannot confirm, but the problem we had was with the pump over running and also this pulsating problem. The flow adjustment screw is against the floor so no access is given to adjust.
Thanks
Andy
Jennifer
these investigations are in addition to the process sheet showing fault finding and how to adjust the pump
Regards
Kath
these investigations are in addition to the process sheet showing fault finding and how to adjust the pump
Regards
Kath
Hi,
I am not familiar with the details of the latest pump systems fitted to caravans, but from the descriptions it sounds as though Swift are fitting an internal pump, with an integral pressure switch. I assume that these will be similar to the Sureflo type of pump.
The Sureflo pumps use a diaphragm mechanism which is a positive displacement design. This is quite different to the centrifugal systems used in submersible pumps.
An uncontrolled diaphragm pump is capable of delivering very high pressures, so it is essential that they are used with a pressure switch. This not only protects the caravan pipework form excessive pressure but it also protects the pump motor by cutting the power to the motor before it stalls. Most diaphragm pumps have the pressure switch built into them.
By way of a comparison, the submersible pumps in caravans will not produce excessive pressure, and a restricted output dose not stall the pump, but most submersible designs rely to some extent on the passage of water through the pump to cool the motor. So these pumps are either controlled by switches in each tap, or a pressure switch.
Jennifers post of the 24th July, give a very good description of the operation of a pressure switch.
If a system is pulsing, then it is the result of the pump raising the pressure in the pipe to trip the pressure switch faster than the water is being used. This more likely on the cold system, as there is less volume in the cold pipework compared to the hot (the storage hot water heaters add volume but more importantly they incorporate and expansion air cap). Because the manufacturers use a flexible plastic hose, it does provide some elasticity and can absorb some of the presure variation - but not a lot.
A pulsing pump can also cause the shower to alternately run hot and cold. The reason for this is that when the pump runs it adds pressure to both hot and cold systems. The hot system has an expansion air cap which acts like a spring and is compressed when the pump runs. When the pump turns off, the cold water flow stops immediately, but because the water heater has a none return valve on its cold water inlet, the pressure is retained in the hot tank by the air cap, which continues to push hot water out.
There are a couple of things to try:-
If the pressure switch is tripping in and out when the tap is open, try raising the switch setting a little. This will raise the pressure and might improve the shower. Don't over do it as too much pressure may blow some of the pipe fittings or taps.
If an accumulator bottle with an air cap is added to the cold system, this will smooth out the flow. To prove it, use an old 2 litre carbonated pop bottle turned upside down is about the right size. And connect it to a cold tap turn the tap on and allow the pump to run. It will partly fill the bottle, but then stop as the pressure equalises. Try any other tap in the caravan and see the difference it makes.
I am not familiar with the details of the latest pump systems fitted to caravans, but from the descriptions it sounds as though Swift are fitting an internal pump, with an integral pressure switch. I assume that these will be similar to the Sureflo type of pump.
The Sureflo pumps use a diaphragm mechanism which is a positive displacement design. This is quite different to the centrifugal systems used in submersible pumps.
An uncontrolled diaphragm pump is capable of delivering very high pressures, so it is essential that they are used with a pressure switch. This not only protects the caravan pipework form excessive pressure but it also protects the pump motor by cutting the power to the motor before it stalls. Most diaphragm pumps have the pressure switch built into them.
By way of a comparison, the submersible pumps in caravans will not produce excessive pressure, and a restricted output dose not stall the pump, but most submersible designs rely to some extent on the passage of water through the pump to cool the motor. So these pumps are either controlled by switches in each tap, or a pressure switch.
Jennifers post of the 24th July, give a very good description of the operation of a pressure switch.
If a system is pulsing, then it is the result of the pump raising the pressure in the pipe to trip the pressure switch faster than the water is being used. This more likely on the cold system, as there is less volume in the cold pipework compared to the hot (the storage hot water heaters add volume but more importantly they incorporate and expansion air cap). Because the manufacturers use a flexible plastic hose, it does provide some elasticity and can absorb some of the presure variation - but not a lot.
A pulsing pump can also cause the shower to alternately run hot and cold. The reason for this is that when the pump runs it adds pressure to both hot and cold systems. The hot system has an expansion air cap which acts like a spring and is compressed when the pump runs. When the pump turns off, the cold water flow stops immediately, but because the water heater has a none return valve on its cold water inlet, the pressure is retained in the hot tank by the air cap, which continues to push hot water out.
There are a couple of things to try:-
If the pressure switch is tripping in and out when the tap is open, try raising the switch setting a little. This will raise the pressure and might improve the shower. Don't over do it as too much pressure may blow some of the pipe fittings or taps.
If an accumulator bottle with an air cap is added to the cold system, this will smooth out the flow. To prove it, use an old 2 litre carbonated pop bottle turned upside down is about the right size. And connect it to a cold tap turn the tap on and allow the pump to run. It will partly fill the bottle, but then stop as the pressure equalises. Try any other tap in the caravan and see the difference it makes.
Your assumptions about the system are pretty accurate.
We have no problems with the shower flowing hot and cold, or with pulsing when on full flow. Our shower flow/pressure is very poor even on full flow, but temperature is good.
Our pulsing comes when using cold water on less than full flow.
And is accompanied by a loud knocking noise in the pipework just under the head of the bed.
Our handbook describes the Shureflo pump and accumulator, but we have a (similar, but lower flow/pressure) Flojet pump and NO accumulator, and therein lies the problem.
As you say, an accumulator would solve the pulsing problem, and we reckon that a better pump could improve the shower.
Our pump also has the inaccessible pressure adjustment screw, but our dealer has had the pump out and in and tried all sorts of adjustments to no avail. Nothing stops the pulsing or improves the shower.
We are hoping Swift will come up with a solution soon, and there is apparently a different shower head we can try.
We have no problems with the shower flowing hot and cold, or with pulsing when on full flow. Our shower flow/pressure is very poor even on full flow, but temperature is good.
Our pulsing comes when using cold water on less than full flow.
And is accompanied by a loud knocking noise in the pipework just under the head of the bed.
Our handbook describes the Shureflo pump and accumulator, but we have a (similar, but lower flow/pressure) Flojet pump and NO accumulator, and therein lies the problem.
As you say, an accumulator would solve the pulsing problem, and we reckon that a better pump could improve the shower.
Our pump also has the inaccessible pressure adjustment screw, but our dealer has had the pump out and in and tried all sorts of adjustments to no avail. Nothing stops the pulsing or improves the shower.
We are hoping Swift will come up with a solution soon, and there is apparently a different shower head we can try.
Has Swift got back to any one with the process sheet to help with this issue I have sent 2 e-mails to enquiries@swiftleisure.co.uk one on Sunday and one on Tuesday as yet no one has even acknowledged receiving my messages even though I asked for a read receipt to be sent back!
Daniel
We are currently working on emails that we received 3 September. We will be responding to you shortly.
Regards
Kath
We are currently working on emails that we received 3 September. We will be responding to you shortly.
Regards
Kath
Swift Response on the Truma Flojet Pump
Swift used the Shurflo pump for many years. We decided to change over to the Truma Flojet in 2008.
There has been some concern from you all regarding, noise, vibration and pulsating. We have investigated this feedback with our supplier and these are our findings.
The Flojet pump is marginally quieter than the Shuflo.
The reported findings can be eliminated by following our trouble shooting guide for identifying any problems and adjusting the pump setting.
Therefore if you have problems please
1 Contact your dealer who will follow the trouble shooting guide to determine the problem
2 If you prefer, you could use the trouble shooting guide yourself in the first instance.
3 If the problem persists, once the recommendations on the trouble shooting guide have been carried out, Truma should be contacted
4 Truma will investigate further and will replace any faulty pump
The trouble shooting guide is available from us and our email address is enquiries@swiftleisure.co.uk
Regards
Kath
Swift used the Shurflo pump for many years. We decided to change over to the Truma Flojet in 2008.
There has been some concern from you all regarding, noise, vibration and pulsating. We have investigated this feedback with our supplier and these are our findings.
The Flojet pump is marginally quieter than the Shuflo.
The reported findings can be eliminated by following our trouble shooting guide for identifying any problems and adjusting the pump setting.
Therefore if you have problems please
1 Contact your dealer who will follow the trouble shooting guide to determine the problem
2 If you prefer, you could use the trouble shooting guide yourself in the first instance.
3 If the problem persists, once the recommendations on the trouble shooting guide have been carried out, Truma should be contacted
4 Truma will investigate further and will replace any faulty pump
The trouble shooting guide is available from us and our email address is enquiries@swiftleisure.co.uk
Regards
Kath
Facebook
Twitter