House has bad mains pressure, so previous owner installed a quot;Holding Tankwhich stores water from the mains, before pumping it into the house for the internal tanks.However, after some recent plumbing work when the mains was turned off, it's running a little weird. The pump seems to be constantly running, although at a very low level, and some times when the taps/fawcets are opened, they seems to be nothing for up to 30 seconds (only air), and then the water rushes out. Same thing for toilet/WC cisterns..Any advice/pointers appreciated.CheersJM
Sounds to me, like the pressure needs to be drained out of your storage tank..............good luck and have a nice new year.
Sounds like your tank is water logged, too much water and not enough air in the tank. If it is a bladder pressure tank, and the bladder gets a hole in it, it causes the same thing, and will need to be replaced.
If the possibility exists then relocating the pump below the level of the water source prevent air entering the pump. Having leaks in pipes and seals will let in air all the time and should be corrected. Many centrifugal pumps have a priming hole that is on top to fill the pump with water if they are not self priming but you need to make sure that the pump does not drain empty while closing the hole and starting the pump. Some pumps have a priming tank that is filled with water and then the opened to the priming port, these can be used with the pump already running and will collect the air bubles from the pump while it is starting. Positive displacement and self priming pumps create sufficient suction/vacuume to draw the colum of water intot the pump to get going and if these fail it is due to excess height above the suction water level or leaks in pipes or seals.
If you are using a standard well pump, then there should be a check valve in the pipe between the holding tank and the pump. In a well it will be a foot valve, but may also have been a simple check valve. The work on your mains may have introduced dirt into the valve and prevents if from sealing and maintaining the pressure in the system when the pump stops. Someone also suggested that the pressure tank (not the holding tank) associated with the pump has become water logged. If that is the case then a small volume of water coming out of the pressure tank will cause a large enough pressure change to keep the pump working. Last possibility, there has to be a sensor that determines that the level of the water in the holding tank is low and will turn on the mains supply and when the level gets high enough that the mains supply is turned off. This can be a pressure switch or a mercury switch similar to one with a sump pump, etc. So my suggestions are: Check to make sure that the holding tank is clean and there is no sediment in it. Check to make sure that the holding tank fills when the water level drops, (it appears to stop when it is full). If you do this next procedure, make sure that you know how to prime your pump. I would also turn off the hot water tank. If it is a foot valve, remove the foot valve by removing the clamp and then back wash it to clean out the dirt. If it is an in-line check valve then remove the pipe. between the pump and the holding tank and invert it, and run water through it to clean out any sediment, then replace the pipe. Drain the pressure tank, and if you can pump some air into it. Then make sure that everything is connected, prime the pump and turn it on. Make sure that everything is working, then at each tap, especially the hot water taps, turn them on and leave running until the water flows smoothly. When all of the air is out of the system then turn on the hot water tank.
