Pump coming on alot

MuddyDog

We have a water pump in the attic that comes on every few minutes. Probably every 2 mins on average but at times when it goes mad it can be every 45 seconds. It'll come on for about 5-10 seconds max. No taps will be on etc.

I've attached pics of the pump and the configuration in the house. The pressure reading pic I've attached we've been told should stay up at around the 2 mark but every 2/3 weeks we have to open the tap connected to it as the pressure seemingly drops to 0 by itself slowly.

Any ideas of what could be causing this or how to diagnose and fix?

MuddyDog

MuddyDog wrote: »

We have a water pump in the attic that comes on every few minutes. Probably every 2 mins on average but at times when it goes mad it can be every 45 seconds. It'll come on for about 5-10 seconds max. No taps will be on etc.

I've attached pics of the pump and the configuration in the house. The pressure reading pic I've attached we've been told should stay up at around the 2 mark but every 2/3 weeks we have to open the tap connected to it as the pressure seemingly drops to 0 by itself slowly.

Any ideas of what could be causing this or how to diagnose and fix?

Pic of the actual pump:

shane b

I have the same pump in my house. It's a grundfos mq3 and there is 3.5 and a 4.5 bar model. Last year mine was taking about 30 seconds after you opened a tap before it would start pumping. Turns out it was a faulty card. So Can't help you diagnose the issue but If your around Dublin there is a guy in balbriggan that fixes them, he has an ad on adverts.ie or try Grundfos in Ballymount.

whizbang

You need to go back to the original installer with that setup. Leaks in that system can be disastrous.

MuddyDog

whizbang wrote: »

You need to go back to the original installer with that setup. Leaks in that system can be disastrous.

Thanks. Inherited the system so no idea who installed it. Should I just go for a local reputable plumber then?

TECH85

Does the prv ever release water ?
Have you checked if there is still a charge in the expansion vessel ?

Conservatory

Check your toilet cisterns. Probably faulty ball valve.

MuddyDog

TECH85 wrote: »

Does the prv ever release water ?
Have you checked if there is still a charge in the expansion vessel ?

What do you mean release water? The pressure drops to 0 after 2-3 weeks and I open the valve to top it back up if thats what you mean?

How do I check the charge in expansion vessel?

MuddyDog

MuddyDog wrote: »

What do you mean release water? The pressure drops to 0 after 2-3 weeks and I open the valve to top it back up if thats what you mean?

How do I check the charge in expansion vessel?

Got my answer from google. Ok so I checked all 3 expansion tanks and no water was coming out of the air valve when I pressed it in with a screwdriver. However no air noise came out of any of them either? Does this mean that they all need charging?

Eamon34

yes .there are two presser vessel in your system, a small black one on pump and the red one. take some water out of system and pump them up

MuddyDog

Eamon34 wrote: »

yes

1.5 bar enough for all 3?

Eamon34

go for it see if it holds take a little water out before pumping it up

MuddyDog

Eamon34 wrote: »

go for it see if it holds take a little water out before pumping it up

tested the pressure with a proper device. the red vessel had 1 bar and the other 2 had 0 pressure/it wouldnt read it.

I tried pumping in air using a bicycle pump with the correct attachment but I could not get air into the vessels as it felt like the vessel was stopping the pump getting air in!

Any ideas?

MuddyDog

MuddyDog wrote: »

tested the pressure with a proper device. the red vessel had 1 bar and the other 2 had 0 pressure/it wouldnt read it.

I tried pumping in air using a bicycle pump with the correct attachment but I could not get air into the vessels as it felt like the vessel was stopping the pump getting air in!

Any ideas?

Ok so I shut the water supply off, drained the system and then was able to pump air into one vessel. Now the pump still comes on but it does so much less. Probably once every 15 mins or so now.

bourkg

I have a Grundfos MQ3 -45. Today it would not start (middle of corona lock down of course). I was unable to get a plumber to assist so I decided to try an tackle the job myself.

On a side note it was also starting about every two minutes even when there was no water flow (There is was a tap at both ends that I could turn on/off to confirm no water flow)

When the pump was turned on it would make a sound that it was trying to turn but failing so my first assumption was that there was grit stuck in the propellers. I followed the instructions found in the following youtube: https://www.youtube.com/watch?v=yFGV2JcEm8Q

I found no evidence that there was grit stuck in there although I did find evidence that someone had previously opened it (I moved into second hand house some time back) and had sheared off one of the screws holding the cover on. What I did notice was that when I moved the motor shaft the motor would start which indicated a bad capacitor. I managed to find a pump supplier who was willing to sell me a matching capacitor and some silicone grease.

I re-assembled my pump and hey presto it's now working again. To my pleasant surprise, the pump is no longer starting every two minutes. I suspect the last person to open it did not grease up the o rings as shown in the video allowing the water to leak back through the pump. Also as a point to note, there is no pressure in the little tank, but its still not constantly starting when taps are not turned on.