Pump turns on briefly for unknown reason and then off again

bazwaldo

Hi,

I have a Stuart Turner negative head pump which was installed about 6 years ago (I can get the model number later). Ever since then and it seems to getting worse, the pump turns on a 5-10 seconds and then turns off again. This happens about every hour or so. Its really annoying as the pump is in the hotpress which is in a bedroom and its quite noisy and particularly noticable at night.

The pump serves the attic bathroom which has a hot+cold for the sink and shower, and a toilet. Even when these are not used all day, the pump continues to turn on briefly and then off again.

Any ideas on what the problem is and how to fix it?

Thanks

Qwerty?

bazwaldo wrote: »

Hi,

Any ideas on what the problem is and how to fix it?

Thanks

I would have thought a leak, but if its leaking enough to cause the pressure to drop enough every hour or so, I would have thought you would have had found problems in 6 years.

lezor

Is there a non return valve before the pump?

creation mark

The pressure vessel may need to be recharged, had the same thing happen with my one, failing that check that the toilet isn't overflowing, even slightly. Look in the bowl and check for a trickle of water around the sides of the pan.

Mark

bazwaldo

I'll check for non return valves when I get home this evening. I inspected it a little yesterday and see that there are stop valves on the inputs but nothing on the outputs. I was hoping I could block the outs so I'd know if the problem was the pump or if there was a leak. The pipes run up from the hotpress and around half the attic before getting to the toilet. Most of this run is inaccessable. But if there was a leak, you would expect after 6 years to see some evidence.

Whats a pressure vessel and how can it be recharged?

There's no trickle from toilet or from the overflow. Once the cistern is full there is nothing coming out of the valve. Not a drip.

BTW, its a M330N model pump.

LIFFY FISHING

the pressure vessell is the silver bottle type of cannister sitting on the bridge pipe of the pump, test it like a bicycle tyre, it should hsve .9 of s bar, if it hasnt .9 bar use a bicycle pump and pump it up to that pressure.

creation mark

LIFFY FISHING wrote: »

the pressure vessell is the silver bottle type of cannister sitting on the bridge pipe of the pump, test it like a bicycle tyre, it should hsve .9 of s bar, if it hasnt .9 bar use a bicycle pump and pump it up to that pressure.

You won't get it up to 9 bar with a bicycle pump im afraid, trust me, I tried lol. I turned off the valves to the pump, unscrewed the vessel & took a stroll down to the garage and used the air pump there.

K.Flyer

If you have inlet and outlet valves fitted you can determine if it is a pump issue or a leak.
Allow the pump to pressurise and shut off the outlet valves.
If the pump loses pressure and cycles again then its a pump issue.
Most likely the built in non return valves on the pump are giving trouble or the pressure switch is failing.
From experience 9 times out of 10 it will be the non return valves. It might only be something caught in them.

LIFFY FISHING

Lads .9 of a bar .9 not 9 bar !!!!!

bazwaldo

I pumped up the pressure vessel using a good foot pump. The vessel is so small it took about half a push to get it up to 40PSI and I only wanted 13PSI (which is .9 bar). So I have no exact PSI as you lose a little PSI when you detach the pump.

Anyway, it was late last night when I got to do this and the pump is working correctly and I have not heard it turn on occasionally. Fingers crossed and a few days of it not happening to be sure as its only on for a few seconds and most of these times could out of ear shot.

I didn't see any non return valves before the pump. I found instructions online (http://www.styleoflife.co.uk/media/import/STUART%20TURNER%20NEGATIVE%202.0%20BAR%20TWIN%20INSTRUCTIONS.pdf) which said they should not be used in installation. Unfortunately there are no gate valves in the outs of the pump so I can't isolate it.

Thanks for all the help and I'll post back with results either way.

K.Flyer

Non return valves are built into the pump on the outlet (longer) side of the pump head. Remove the two small chrome screws holding each side down. Lift away the bridge, vessel, pressure switch assembly and you will see them.
The can be prised out with a grips and checked for wear, dirt caught in them or replacement.
Be careful not to damage or pinch the light O - rings when re-fitting everything.

creation mark

LIFFY FISHING wrote: »

Lads .9 of a bar .9 not 9 bar !!!!!

hahaha...of course:eek:

bazwaldo

Well, pumping up the pressure vessel didn't work. I'll have to disconnect the out connections, add gate valves and check the non return valves. I assume there is no way around having the pipes contents spill out water once disconnected. From the flexible connector from the pump, there's a few inches of copper and a compression joint connection to qualpex which runs for up to attic.

K.Flyer

Save the mess and hire a small water vacuum from the hire shop. Have the hose up against the connections as you open them to catch the water spilling out, keeps the area nice and dry.
You could take the connector between the copper and the pex pipe out and fit the valves in their place.
As for the non returns, even slight pitting on the contact surfaces can cause you problems, so they need to be examined carefully.

LIFFY FISHING

If pumping the vessell helped for a short while and you are back at square one, its very likley the pressure switch has gone faulty, its a black unit which is situated on the transfer bar which the vessell sits on , its a two wire connection, any spare part for this pump or any Stuart Turner/ Monsoon pump can be obtained from Modern Plant , Naas rd, 01 4591344, they will also run through technical advise with you.

bazwaldo

Finally got to go at this at the weekend. First put on the gate valves. Isolating the pump, it still turned on by itself so that meant the pump was the issue and not a leak. Next I went to check the non return valves.

With three wires attached from the pump to the pressure unit, it was a bit tricky to access them. With the scripts I prized them out. There was a tiny amount of limescale and some of the paint/enamel on the valve had came away. I scraped off the limescale and cleaned each valve up. Put it back together again and tested it out.

And so far so good. I'm delighted! Thanks all for the suggestions. Wasn't too hard and all fixed for the price of two gate valves and an hour.

EDIT: Scratch that. Heard it twice tonight go off for no known reason. Arrrggghhhhhh!!!!

First guess is to replace the non return valves. Wonder how much they are? Are they standard or specific to Stuart Turner pump and must be bought in that place near Long Mile Rd

K.Flyer

You will need the model / serial number just to be safe when buying them.
You are better going to Modern Plant on the Naas Rd as they will supply you with the correct ones.
They cost approx 40- 45 euro inc vat for the set, and a pressure switch is about 70 euro.

bazwaldo

Thanks. I'll try the valve first and see how I get on. Its €33+VAT. Dunno if thats for one or two valves. Pricey for what you get.

LIFFY FISHING

bazwaldo wrote: »

Thanks. I'll try the valve first and see how I get on. Its €33+VAT. Dunno if thats for one or two valves. Pricey for what you get.

Not pricey when you can get the parts readibly, & the pump costs around 700euro !

K.Flyer

That price is for the two valves.

As LiffeyFishing says, not pricey considering you can still get them so easily.

el_capitan

Hi there, don't suppose you recall this thread from 2 years ago, but i've been reading it through as i'm experiencing the same problem with the stuart turner pump. Had tge plumber out twice and he recomended i changed the pressure vessel. That arrived this week (€100) fitted it but within an hour, the same problem. Pump kicks in every few minutes. No leaks anywhere so now suspect its the non return valve on the pump. Do you remember what you did to fix that? Cheers.

el_capitan

Hi there, don't suppose you recall this thread from 2 years ago, but i've been reading it through as i'm experiencing the same problem with the stuart turner pump. Had tge plumber out twice and he recomended i changed the pressure vessel. That arrived this week (€100) fitted it but within an hour, the same problem. Pump kicks in every few minutes. No leaks anywhere so now suspect its the non return valve on the pump. Do you remember what you did to fix that? Cheers.

bazwaldo

I replaced the non return valves and it sorted the problem. It's been fine since.

K.Flyer

If you have shut off valves on the outlet sides of the pump then shut them off and see if the problem stops.
If it does stop then you have a drip or a leak somewhere. If it continues to keep starting then its the non return valves

el_capitan

Good news. Thats what i'll tackle next so. Did you source the replacements in Ireland?

el_capitan

Good news. Thats what i'll tackle next so. Did you source the replacements in Ireland?

bazwaldo

Yeah. A place called Modern Plant near the Red Cow Roundabout. Looking above it cost €33+VAT. I think I looked online too and it was the same price from UK but I wanted it in a hurry so just went to the shop.

MrCostington

Hi, Old thread I know but this may help someone else.

I had (hopefully past tense!) the same problem with my Stuart turner Monsoon pump and tried pumping the pressure vessel but it did not fix it.

I found a manual online, and it seems you have to A) turn off the power supply and open a tap while you pump it up.

This seems to have done the trick for me.

The Stuart Turner site has manuals for old and new pumps (cannot post links)