Why Is The Pump On My Water Tank Working Away

[Leesy]

Hi all,

I'm trying to get to grips with the central heating and hot water system in my new house. So I've gone to the internet for help as usual

I've got an open vented system for the hot water. There's a expansion tank in the loft and I've got a large hot water tank in the airing cupboard with several pumps attached to it.

My first question is this. Right now, one of the pumps on the hot water tank is whirring & working away although it's quite late at night (gone 10pm at the moment). The heating & hot water are off according to the electric thermostat downstairs and has been for several hours. The hot water isn't meant to kick in again till early tomorrow morning. So why is the pump still working? It's making the hot water tank kick off enough heat to make the house warmer than it really needs to be at this point of time.

I can turn the pump off by killing the power to it, but I'd rather know what is telling it to pump away at this strange time.

Thanks for anyone's input on this.

 

[45yearsagasman]

Hot water tank, several pumps? A picture paints a thousand words.

 

[Dopeydaz]

Sounds like a boiler mate? 3 pumps? On this system the hot water is always on. The timer on the tank is for the heating. Yes it sounds odd. You can't turn the hot water off and it will fire the boiler any time it needs to heat water. Some models need the hot water storage to be satisfied before they will start the central heating pump allowing you to have heating.

 

[Dopeydaz]

Sorry, it's late I may have mis understood your post, forgive me if I have!

 

[Leesy]

No worries Daz, it's late here too It's not the boiler, that's downstairs. Having a timer up here somewhere would make more sense if it's heating up the water on it's own accord. I can't see anything though.

These are taken with my iPhone whose flash is utterly pointless so I've had to use a flash light to brighten things up a bit. Oh and excuse the dust and towels on the floor

Here's the tank & the pumps from a far: http://dl.dropbox.com/u/135227/Photo1.jpg

And here are two shots of the pumps closer up:
http://dl.dropbox.com/u/135227/Photo2.jpg
http://dl.dropbox.com/u/135227/Photo3.jpg

In the picture you'll see the three pumps. There's the black compact one & two grey motorised pumps (that's what they are labelled anyway). It's the black pump doing all the work at the moment.

Also I forget to mention I believe the heating may involve a old parkray heating system linked to the fireplace in the room below the hot water tank. We aren't using this though and are looking into getting it removed shortly.

 

[Dopeydaz]

Yep I completely misinterpreted your post! I thought it sounded like a "boilermate" by gledhill.

2 of those appear to be motorised valves and one is a pump. If everything is turned off and it's still running then I'd suggest that one of the 2 ports are sticking. Are the radiators heating up? If yes then it's the heating one that is sticking. If no then it's the hot water one. It's hard to see if they are demountable head 2 port valves.

 

[Dopeydaz]

One of the valves will be on the pipe work that goes into the cylinder and one will not go into the cylinder. So if radiators are hot it will be the one that the pipe work doesn't go into the cylinder. Is there a button on the side of the grey boxes? Not a lever labelled A-B but an actual buton on the left side?

 

[plumbplumb]

Little button on the side is to remove the valve head

 

[biscuit77]

The pump is running all the time because one off those white plastic valves are siezed,they are your zone valve and it is them that supply power to your pump and boiler,as with the post above if your radiators are heating then its your heating valve or hot water valve if water hot all the time.

 

[plumbplumb]

The lever A to B is to switch the valve to manual open position.

Turn heating and hot water off at timer.

THIS IS NOT A DEFINITIVE TEST

Try to move the levers over you should feel some resistance on the levers and hear a whirring inside. This is the lever pushing the valve motor over.
If you struggle to push one that is likely your knackered valve.

This will not however indicate if a valve is shutting but the microswitch is sticking inside the valve (You may have a microswitch sticking and a valve passing)

If you locate faulty head you can change these without draining off.

Press button, remove head and swap

 

[Leesy]

Yes, you're right - the grey ones are motorised values, not pumps. The radiators are not hot at the moment so we'll say it's the hot water value then.

THe values's are listed as ACL Lifestyle 679H308-30L1. And judging by what I'm reading they do seem to be removable. although I won't try this late at night

If the one of ports are sticking, is it a simple job to unstick it?

 

[Leesy]

OK. Thanks for the info all. I'll give it a shot tomorrow and see what happens

 

[seco services]

9/10 times if the valves jammed open it'll be the brass body part thats seized not the actuator.

Check the marker on the side whats it pointing to A or B ?
Or feel the end lever has it got resistance or is it floppy ?

 

[plumbplumb]

No replace the valve head.

Like I said it's not a definitive test. I use it to point me in the right direction before I get my multimeter out and start testing away. I always prove it with a multimeter afterwards.

Usually if you cant budge one of the levers or it slips left and right with no resistance it indicates a seized motor in the valve. These can be changed and are about £12.00 (can be a little fiddly)

If the lever moves and you can hear the motor whirring then it indicates the motor is ok. However if sometimes your boiler stays on and sometimes it goes off this indicates that the little microswitch in one of the valves is occasionally sticking keeping power on to your pump and boiler.

A little long winded but it's the best I can do to explain

 

[plumbplumb]

My no replace valve head was response to 'it is easy to unstick (meaning its not easy to unstick microswitch)

It's all getting blurred now