Stuart Turner 4 bar negative head pump intermittent switch on & off

ZV Yoda

Hi folks,
Per above, our Stuart Turner 4 bar negative head pump intermittently switches on & off. It happens ever couple of hours for about 3 secs. It's located in the hot press (2nd floor of house) and feeds the loo, handbasin & shower in the attic above.

Per the Stuart Turner FAQs, I've checked the following:
1. Sink taps - definately not dripping (bone dry)
2. Cistern - likewise
3. Shower - likewise

Before I call somebody out, is there anything else I should check? Not sure if it's relevant, but the attic room get very little use, so the ensuite loo/sink might get used a handful of times in any month. The shower even less.

Thanks

Carlow52

on neg head pump is there a 'pressure vessel'
the faq's u list are for + head.

ZV Yoda

Carlow52 wrote: »

on neg head pump is there a 'pressure vessel'
the faq's u list are for + head.

Hiya... yes, it does have a pressure vessel. The FAQs I checked are here. Didn't realise the FAQs distinguish between + & - head pumps.

Carlow52

ZV Yoda wrote: »

Hiya... yes, it does have a pressure vessel. The FAQs I checked are here. Didn't realise the FAQs distinguish between + & - head pumps.

from the link

Check for any leaks in the system. Check the tap washers and pipe joints etc. Check the pre-charge pressure in pressure vessel, but to do this the pump must be switched off first and the pressure released from the system.
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ZV Yoda

Carlow52 wrote: »

from the link

Check for any leaks in the system. Check the tap washers and pipe joints etc. Check the pre-charge pressure in pressure vessel, but to do this the pump must be switched off first and the pressure released from the system.
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Yeah, I read that part... I've already checked for leaks (at least in the places I can access). I've no idea how to go about "releasing pressure from the system".

Carlow52

switch off power to the pump and open a tap, that kills pressure in pipes so when u test the pressure in the pressure vessel it is the pre-charge pressure only and not pre-charge plus the 4 bar.

There should be a valve cap like on a tyre or bike visible which u screw off and use a tyre pressure gauge to measure the pre-charge pressure.

I am not a plumber but the theory is right.

Look at the sites of other pumps for more data on the problem: wilo/grundfus/salamanca

ZV Yoda

Carlow52 wrote: »

switch off power to the pump and open a tap, that kills pressure in pipes so when u test the pressure in the pressure vessel it is the pre-charge pressure only and not pre-charge plus the 4 bar.

There should be a valve cap like on a tyre or bike visible which u screw off and use a tyre pressure gauge to measure the pre-charge pressure.

I am not a plumber but the theory is right.

Look at the sites of other pumps for more data on the problem: wilo/grundfus/salamanca

OK, thanks for that... will take a look at doing this tonight

Carlow52

ZV Yoda wrote: »

OK, thanks for that... will take a look at doing this tonight

open hot and cold taps to kill pressure on both: I presume its a dual pump, if not no worries, theory is same.

By tonite the experts will be on here:)

steder

ZV Yoda im just wondering if you got the problem sorted im having the same probs with my pump.....:(

cpbobo

Hi, I have the same issue. Did you ever get this resolved?

Thanks

aujopimur

Check the toilet cisterns, these are the usual cause of nuisance pump running.

cpbobo

what do i check for. The toilet fill after flushed and the pump cuts off.

aujopimur

There sould be an isolating valve for the cistern, if not, see if it's continuing to let water in.
It takes a very small amount of water to trigger the pump.