water pump problem

[wolfie8832]

USome times. When refilled water tank the water pump doesnt turn off. Also the hot water tank system starts knocking. I can stop it by twisting the red. Cap on hot water tank and water fills tank . Sorry if this don't make sense typing on. Mobile about to throw it out window.

If anyone can help be great.still stuck in basin

[canaldrifter]

Hard to make out what's going on there, but it could be a venting problem?

 

Water pumps work on differential pressure. If the pressure in the storage tank is higher than that in the system the pump will run.

 

You say you have a 'red knob' on the storage tank as well as the hot water tank? Two relief vales?

 

Strange.

 

Tone

[wolfie8832]

Sorry one red value on the hot water tank. When I twist it water runs in and the tank stops knocking. It's as if it needs bleeding air out of stsyem. Surley I don't need to do this every time I fill with water......thank-you. Mark

[Smelly]

It does sound like you're gathering air in the calorifier. Do you run the tank dry?

 

If we run dry the calorifiers tend to bubble a bit as air is pumped in; one could describe it as "knocking". Soon sorts itself out when we start the engine as the PRV opens once the water heats up enough and that blows the air out.

 

I wonder whether a blocked vent on the water tank and ensuing back pressure might give similar symptoms...

[Albion]

Sounds as if you have air in the calorifier, as has been suggested. The red knob that you're twisitng sounds like the pressure relief valve (PRV) and that you are venting the tank that way. The pump won't switch off because it is pushing water into the calorifier against the 'springiness' of air instead of water. Fill your main water tank, switch the pump on, open a hot tap (to start with) until water runs cleanly (no spitting) from the tap and then close the tap. The pump will probably stop soon after this. You may also need to purge the cold water pipes as well by repeating the tap opening for the cold tap. Then, once you've got a solid fill of water everywhere the pump should be back to normal.

Roger

[wolfie8832]

Yes does sound like that's the problem..I will make sure the tank vents clear thanks again for your advice.......alls I need. now is for the seven to drop in level to get home. stay here much longer i will need a pasport.....mark

[boatyboy]

Try this one ............... Turn off your water pump to the taps.Run hot and cold taps till no water comes out.Leave cold tap on,but turn off hot. Unscrew shower head,turn shower setting to hot and turn it on.Attach mouth to shower hose and blow for all you are worth.You will now get very dizzy.Not to be attempted if you got a weak heart

This should push water around the system (well it did mine) I had an air lock problem,and this exercise did it ok for me.

Dave

Edited February 10, 2011 by boatyboy

[twbm]

Sounds like the calorifier is at or near the high point of the system. Would this not be alleviatd with a strategically placed non-return valve to stop it draining off when the tank empties?

[ditchcrawler]

On some seups if the pump is running while you fill the main tank, it is possible to suck air into the plumbing system with the pump.