Shurflo pump running on

[Pudsey Bear]

Just thinking Kev.
IF it only does it when you've run off some HOT water AND when you're using EHU then it could be the faint 'kettling' sound coming from the heating element in the hot water tank.

hot or cold makes no difference Merl, and we're never on EHU when away, the the Trauma ultrastore is silent apart from when it cycles the flame on and off if I forget to turn it off.

 

[Rumour]

hot or cold makes no difference Merl, and we're never on EHU when away, the the Trauma ultrastore is silent apart from when it cycles the flame on and off if I forget to turn it off.

Exactly the same as ours. It makes the correct noise when pumping and stops normally. But maybe a bit later, or even a while later, we get a whirring sound! When I turn off the power to the pump, it stops. If I put the power back on straight away, no sound. So it is definitely the pump.

 

[Pudsey Bear]

Exactly, have you sussed out the cause.

 

[Rumour]

Exactly, have you sussed out the cause.

Sadly no and the van is OR at the moment due to electrical meltdown of the heater wiring. Averted a fire by minutes! But will check it again in a few days after I strip out and reconnect the batteries.

 

[Pudsey Bear]

No rush.

 

[merl]

Sadly no and the van is OR at the moment due to electrical meltdown of the heater wiring. Averted a fire by minutes! But will check it again in a few days after I strip out and reconnect the batteries.

No rush.

Certainly an odd one guys. Must admit I'm quite intrigued
Does the whirring ever start up on it's own or does the pump always have to have run immediately before?

 

[TJBi]

From the manual for my Shurflo pump, Troubleshooting section:

PUMP WILL NOT SHUT-OFF/RUNS WHEN TAP IS CLOSED [check]:

✓ Output side (pressure) plumbing for leaks, and inspect for leaky valves or toilet.
✓ For air trapped in outlet side (water heater) or pump head.
✓ For correct voltage to pump (±10%).
✓ For loose drive assembly or pump head screws

✓ Are the valves or internal check valve held open by debris or is rubber swollen?

✓ Pressure switch operation/adjustment incorrect, refer to shut-off adjustment for switch.

 

[Pudsey Bear]

Certainly an odd one guys. Must admit I'm quite intrigued
Does the whirring ever start up on it's own or does the pump always have to have run immediately before?

Not 100% on that Merlin, I only notice it after the pump has been used so probably, I have the tap/sink dismantled right now so I can't test it.

 

[Pudsey Bear]

From the manual for my Shurflo pump, Troubleshooting section:

PUMP WILL NOT SHUT-OFF/RUNS WHEN TAP IS CLOSED [check]:

✓ Output side (pressure) plumbing for leaks, and inspect for leaky valves or toilet.
✓ For air trapped in outlet side (water heater) or pump head.
✓ For correct voltage to pump (±10%).
✓ For loose drive assembly or pump head screws

✓ Are the valves or internal check valve held open by debris or is rubber swollen?

✓ Pressure switch operation/adjustment incorrect, refer to shut-off adjustment for switch.

Depends on what it means by "running" I suppose, it effectively does shut off when the tap is closed.

 

[merl]

Depends on what it means by "running" I suppose, it effectively does shut off when the tap is closed.

Agree, the pump isn't running on. The whirring sound isn't the pump running, it's something else.
I'd have suspected some sort of mechanical quirk or something unrelated but according to Rumour it stops when the 12v to the pump is removed, further more it doesn't re-appear when the 12v is turned back on...Very weird.
Kev, do you know if the pressure switch works the pump motor directly or does it use a relay too? Not noticed a relay on mine but then again I've never really took any notice.

 

[Pudsey Bear]

Not noticed a relay, not sure what the draw is on one, would it need one or is it built in?

 

[wildebus]

Not noticed a relay, not sure what the draw is on one, would it need one or is it built in?

Sureflo pumps draw approximately 5A when running.

you would not need a relay to run a pump through a typical mechanical switch and it does not have one built in.

Depending on the setup of your motorhome, there may well be a relay for the pump within a power distribution unit. For example, the Sargent EC PDUs have a relay dedicated to the pump within them, but that is because the pump power is turned on and off via a control panel and electronics rather than a mechanical switch. If you were to install a standalone water pump, for example, I doubt very much you would bother powering via a relay and just just a switch

For example, this is a popular [mechanical] pump switch and would be wired between battery (fusebox) and the pump itself

 

[Pudsey Bear]

Mine has the Nordellectro? setup for the control panel and the main distribution board the fuse/relay PCB is not that far from the pump, but in my self-build, I didn't use a relay as it wasn't prescribed so I assume this van hasn't got one either but no way for me to tell.

 

[merl]

Mine has the Nordellectro? setup for the control panel and the main distribution board the fuse/relay PCB is not that far from the pump, but in my self-build, I didn't use a relay as it wasn't prescribed so I assume this van hasn't got one either but no way for me to tell.

I was contemplating if the pump diaphragm switch controlled the pump motor directly or via a secondary relay, my thought was that the mysterious noise could be caused by a faulty relay or its associated flyback diode or suppression capacitor and not the pump motor.
I've found a video on tinternet that shows the pump motor being controlled directly via a microswitch so as David has suggested there doesn't seem to be a relay involved but the relatively high current means the microswitch gets hot and eventually breaks down.
With the above in mind my money is on a faulty microswitch, or a defective suppressor capacitor that's often fitted across switches. if the contacts are not fully opening or the capacitor has gone high resistance but then the pump motor will receive a low current that's not large enough for the motor to run but is big enough to cause it to try and run and simply make a noise.
Microswitch/ capacitor is dead cheap and deffo a DIY job for someone with your skill set Kev, hardest jub will be getting the pump on out to work on it.
Here is the link to the video

 

[wildebus]

FWIW ....
I have a Shurflo pump in my Motorhome and it works great.... Except ..... it would never prime the tank after it ran dry and I had fiddle around for ages opening the outlet and messing around with trying to eliminate airlocks. But once water primed, not a hint of an issue.
removed the pump and tested it with a battery and bucket of water and never any problem on testing.

I spoked to the previous owner after I got fed up with this to see if he had any ideas (not to complain, but he could tell me what he used to do).... He had the same problem and basically he just used to make sure the tank never went dry and on the odd occasion he did he messed around with the pump outlet until it got going again. He said he replaced the pump also to no effect.

After two years of this, I had enough and decided to get another pump just to see.... Got a new Shurflo pump ( like this, but the 30PSI version - https://amzn.to/40fJ78b), fitted it and never had a second of problem since. Primes inside a minute with no intervention.


My takeaway from this was even if something appears to be in working order, and when put on a bench test it tests good, there can still be something wrong but impossible to find.
Life is too short to be lying down with your head in a cupboard trying to get something that apparently works to actually work!

My only regret is not just buying a new pump sooner. Kev ... just get a new bloody pump and have done with!!

 

[Pudsey Bear]

Hmm, not sure he has the same problem though.

But

https://www.amazon.co.uk/Omron-V-15-2C26-K-Action-Switches-Miniature/dp/B072JG87H3/ref=sr_1_1?crid=1FYWHGD9QBAX4&keywords=V-15-2C26-K+Switch+Snap+Action+Micro+Switch+Normally+Closed+for+OMRON&qid=1698320394&sprefix=v-15-2c26-k+switch+snap+action+micro+switch+normally+closed+for+omron%2Caps%2C143&sr=8-1

 

[Pudsey Bear]

FWIW ....
I have a Shurflo pump in my Motorhome and it works great.... Except ..... it would never prime the tank after it ran dry and I had fiddle around for ages opening the outlet and messing around with trying to eliminate airlocks. But once water primed, not a hint of an issue.
removed the pump and tested it with a battery and bucket of water and never any problem on testing.

I spoked to the previous owner after I got fed up with this to see if he had any ideas (not to complain, but he could tell me what he used to do).... He had the same problem and basically he just used to make sure the tank never went dry and on the odd occasion he did he messed around with the pump outlet until it got going again. He said he replaced the pump also to no effect.

After two years of this, I had enough and decided to get another pump just to see.... Got a new Shurflo pump ( like this, but the 30PSI version - https://amzn.to/40fJ78b), fitted it and never had a second of problem since. Primes inside a minute with no intervention.


My takeaway from this was even if something appears to be in working order, and when put on a bench test it tests good, there can still be something wrong but impossible to find.
Life is too short to be lying down with your head in a cupboard trying to get something that apparently works to actually work!

My only regret is not just buying a new pump sooner. Kev ... just get a new bloody pump and have done with!!

I think I have one in the garage somewhere, I bought it for a problem but it was electrical so it's still in its box, but the pump seems to work fine, if it does pack up I'll go further and look for the other pump, but I just wondered why it was whirring after the taps were closed.

 

[merl]

Hmm, not sure he has the same problem though.

But

https://www.amazon.co.uk/Omron-V-15-2C26-K-Action-Switches-Miniature/dp/B072JG87H3/ref=sr_1_1?crid=1FYWHGD9QBAX4&keywords=V-15-2C26-K+Switch+Snap+Action+Micro+Switch+Normally+Closed+for+OMRON&qid=1698320394&sprefix=v-15-2c26-k+switch+snap+action+micro+switch+normally+closed+for+omron%2Caps%2C143&sr=8-1

No he doesn't have the same problem but the vid shows how to swap the microswitch.

 

[Pudsey Bear]

Yeah, handy to know about and you can test it easily enough.


Sort of.

 

[merl]

FWIW ....
I have a Shurflo pump in my Motorhome and it works great.... Except ..... it would never prime the tank after it ran dry and I had fiddle around for ages opening the outlet and messing around with trying to eliminate airlocks. But once water primed, not a hint of an issue.
removed the pump and tested it with a battery and bucket of water and never any problem on testing.

I spoked to the previous owner after I got fed up with this to see if he had any ideas (not to complain, but he could tell me what he used to do).... He had the same problem and basically he just used to make sure the tank never went dry and on the odd occasion he did he messed around with the pump outlet until it got going again. He said he replaced the pump also to no effect.

After two years of this, I had enough and decided to get another pump just to see.... Got a new Shurflo pump ( like this, but the 30PSI version - https://amzn.to/40fJ78b), fitted it and never had a second of problem since. Primes inside a minute with no intervention.


My takeaway from this was even if something appears to be in working order, and when put on a bench test it tests good, there can still be something wrong but impossible to find.
Life is too short to be lying down with your head in a cupboard trying to get something that apparently works to actually work!

My only regret is not just buying a new pump sooner. Kev ... just get a new bloody pump and have done with!!

Yeh but Kev's pump is actually working it's just making a bit of extra noise, all he needs is some ear plugs, cheaper than new pump and easier to fit!