why is my water pump drawing power even when not running?

budgetbuilder

I've asked this question to a few plumbers, the store that sold me the pump, an electrician and none of them at first even understand the probelem which is that the water pump at my well is drawing copious amounts of power even when NOT running. It is not short cycling, which is what they all seem to think I mean when I say that it's running up huge bills. it's working perfectly apart from running up hundreds of euros in electricity bills each month while not even running!!! After my meter was checked by the ESB yet again, the electrician they sent said that there were fluctuations on the circut to the socket that the pump is plugged into. So, I put the pump on a remote control so that there is only power going to it when I want to refil tanks or run a tap. The electricity bill has now shot down to €99, a big drop from the €700 of the previous bill so I'm certain that it's that circut that the problem is on. Now I'm trying to troubleshoot what the problem is before the winter comes because if we get hard frosts and the pump is switched off it will probably freeze solid and burst, just like the previous one did in 2010. I've checked the neutral in the plug for a short and it's all clear. It had a new cut out switch fitted last year but the hefty bills go back at least two years, if not more but have been getting worse and worse. I'm hoping someone on here can point me in the right direction as we had a death in the family a few months ago and have some heafty bills from that to pay for so I can't afford to fork out for a whole new pump which may not even fix the problem. If I'm sure it will, I'll have to find the money somewhere but I don't want to just chuck it away on a hunch that may not fix it. Has anyone heard of this happening before? The pump is a Grundfos, if that's any help.

joewicklow

Are you sure someone isn't "borrowing" your electricity? Run a separate cable over ground to the pump and see if there is any difference in usage.

Wearb

You would probably be better off posting this in the electrical forum. It shouldn't be too difficult to put a meter close to the pump to start the diagnostic process.

budgetbuilder

I'm certain that nobody else is borrowing my electricity. The pump is near the house and I'd see any other cables or disturbances. The nearest other house is about 200m away.

gctest50

some even small pumps have a programmable controller
you can set them to keep "ticking over" all the time ( turning slowly)
i spose it stops it seizing and maintains pressure and stops the seals sticking to the shaft

power it up and see if its spinning ( you'd barely notice it )

source: noticed it before on a little grundfos and wondered what it was up to

freddyuk

I had the same problem but as I monitor quite closely my power usage I spotted it quite quickly. I discovered the well pump was running but not tripping off as it never got to the pressure trip point. There was no water pumping as the tank was full but by feeling the well pipe you can feel the vibration of the pump running. I replaced the pressure switch a while ago but this time it was the pressure vessel which was full of water so the bladder had blown.
A new vessel and careful adjustment of the pressure switch has solved the problem. If the pump pressure (bar) limit is below the switch high pressure limit then it will keep running but not pumping anything.
If it is running up bills it is running!

budgetbuilder

freddyuk wrote: »

by feeling the well pipe you can feel the vibration of the pump running. I replaced the pressure switch a while ago but this time it was the pressure vessel which was full of water so the bladder had blown.
A new vessel and careful adjustment of the pressure switch has solved the problem. If the pump pressure (bar) limit is below the switch high pressure limit then it will keep running but not pumping anything.
If it is running up bills it is running!

It's a surface pump, not one submerged in the well so when it is running it can be heard quite distinctly. The motor does not run when it's not pumping water. Basically, if there is power going to it, it will turn on when I run a cold tap and turn off within a few seconds of turning off the tap once the correct pressure in the pipe is reached. As far as I can tell, the only thing that can be adjusted is the cut out pressure by adjusting the screws on the pressure switch and the bladder pressure by way of an air valve in one end of the tank. It's quite a basic system.

Wearb

budgetbuilder wrote: »

It's a surface pump, not one submerged in the well so when it is running it can be heard quite distinctly. The motor does not run when it's not pumping water. Basically, if there is power going to it, it will turn on when I run a cold tap and turn off within a few seconds of turning off the tap once the correct pressure in the pipe is reached. As far as I can tell, the only thing that can be adjusted is the cut out pressure by adjusting the screws on the pressure switch and the bladder pressure by way of an air valve in one end of the tank. It's quite a basic system.

It should not turn instantly when a tap is turned on. The pressure vessel should supply some water until the pressure drops to the cut in pressure.

clivej

If your bills were €700 then why the heck did you not get it looked at before now. An electrician wouldn't cost that for the day.

If the circuit is taking power then the pump is running or you have a short on the cable going to the pump.

I've seen cables in a conduit with the insulation cut through and covered with insulating tape. Water got into the conduit and the water was boiling but not taking enough to trip the breaker. This was a 3 phase 50amp supply.