electric water pump

irelandhouse · 31-12-2010 9:17am #1

just on this

we have a pump on the hot water cylinder; however this last week during the bad weather - it goes for a few seconds and then stops dead, the tanks up in the attic (2 x 80gal) were full and the heating came on that morning so can only guess that the hot water tank was full also ? 4 pipes come into the pump, gather 2 hot in/out, 2 cold in/out ?

the water was normal from the hot tap around the house?

this week it is working fine ? - would it have been a frozen pipe ?
(if so will trace it back and lag were needed to try and prevent again)

Buford T Justice · 02-01-2011 1:15am

If its a pressure operated pump, then it could have been an airlock that caused it.

Sparkpea · 02-01-2011 9:53am

could be airlock or else filters are normally in the inlet hoses of the pump. if your tank was empty and refilled then you'll theres prob dirt got in the pipes and normally clears at taps but if it went to the pump first the filter would have caught it/blocked it. sounds like the flow switch is cutting out so its not getting full flow.

Damien_d12 · 03-09-2012 11:43am

I emptied my hot water tank and since then the pump is not working. could it be that dirt got into the pump when the tank was emptied and if so what can i do to fix this?

sullzz · 03-09-2012 7:01pm

Damien_d12 wrote: »

I emptied my hot water tank and since then the pump is not working. could it be that dirt got into the pump when the tank was emptied and if so what can i do to fix this?

Is it positive or negative head pump , is there any sound out of it , have you got power to it , what make pump is it , have you got water as far as the pump, mabey put up a few pics of the phmp and surrounding pipework including the cylinder.

Damien_d12 · 03-09-2012 10:16pm

Hi thanks, for the reply. Here's a breakdown of your questions.

Is it positive or negative head pump - not sure

Is there any sound out of it - none whatsoever , when the tap is turned on the water just dribbles out at low pressure but there is no sound from the pump.

have you got power to it - the switch on the wall which feeds the electric cable to the pump has a red LED on so it, which indicates that the power is being feed to the pump.
BTW Before I emptied the tank, I switched the electric mains off at the trip switch so that the pump would be off while the tank emptied and after the tank was refilled I switched the trip switch back on and the pump never worked since.

what make pump is it - there is no manufacture name on the pump.

have you got water as far as the pump - i assumed that if hot water is getting to the sink it has to go through the pump ?

mabye put up a few pics of the pump and surrounding pipework including the cylinder - i've attached two pictures of the pump and boiler and can put more up.

Hope the responses shine some light on this, I've read that sometimes when a tank is emptied the filters in the pumps can get clogged with dirt from the tank so I'm hoping that the problem is something as simple as this!

thanks,
D

sullzz · 03-09-2012 11:18pm

Ok thats a negative head pump, if you look to the very right of the pump you can see a little blact switch /sensor clamped to the pump with an arrow pointing upwards and a cable coming out of it , there is one of these on each side of the pump, if you get a magnet , a fridge magnet should do , and move it up and down against these sensors , it might bring the pump on for you.

Damien_d12 · 03-09-2012 11:57pm

OK, thanks for the advice, there was an arrow pointing up on both black sensors, but when i ran the magnet over both of them it didn't change anything and the pump is still dead.

I've also noticed that when I bleed the silver air cylinder on top, some air comes out - I've done this yesterday and air came out and I did it just now and more air came out so maybe there is air recursively getting trapped in the pump.

sullzz · 04-09-2012 6:59am

I think its time you rang a plumber , even if you get the pump to kick in its not going to work correctly now , the air you released from the silver vessell should be in there , that vesselk is precharged with air , so if you do get the pump to work now it will be constantly switching on and off even with no taps being used , if i were you i would leave it well enough alone and contact a plumber , these pumps are huge money , i think a 2bar one is about 630 euro and a 3 bar one is more so the last thing you want to do is damage it beyond repair.

sparksfly · 04-09-2012 7:31am

Its a Stuart Turner negative head twin pump.
sullzz is correct in all respects.
The air vessel needs to be charged with air to dampen the build up of pressure when the pump starts, eliminating rapid start/stop cycling. This will now have to be recharged.
There is a pressure switch on this air vessel and a flow switch on both the hot and cold outlets. Each can detect a demand for water as soon as a tap is opened or a toilet/washing machine/dishwasher starts drawing water.
A drop in pressure trips the pressure switch and starts the pump. Either or both flow switch(s) then keeps the pump running until the water flow stops. It may be the pressure switch but not a flow switch as it is unlikely that both (flow switches) will fail at the same time.
This can be checked (by a competent electrician) by bridging the connectors (S1 to S1) in the electrical box of the pump. If this starts the pump, the pressure switch is dead. Bridging S2 to S2 or S3 to S3 bypasses the flow switches.
If all this fails, the PC board may be a goner, bridging L (Live) to M(Motor) should start the pump in this case.
All parts mentioned are available from Modern Plant near citywest.

Damien_d12 · 05-09-2012 1:39pm

Ok, so I took the advice and a plumber (with experience in pumps) came out and he put a new PCB in the pump and its working again. cost E170, I guess its away better than replacing the pump anyway.
thanks for all the advice.

D

electric water pump

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