I have a 1998 Compass Rallye, during the day or night the water pump will give the occassional burst of action even if I am not using the taps. I have had a look at the pipes and can't see any internal leaks. If I turn the pump off over night there is a 3 or 4 second fill when turned back on is this normal?
Water Pressure
- Thread starter Fouldsy
- Start date
You dont say what type of water syatem you have (presure or microswitch) I asume it is a presure system and if so this is not unusual as when you use the water heater the presure increases and acordingly when you switch the water heater of the presure reduces as the water cools and the pump kicks to restore the presure.
Hello Mike,
Del may have indicated the cause, however there are other possible causes:
From your description I think it is safe to assume you have a 'pressureised system'. This works by a switch sensing the presure in the coldwater pipe. If the pressure drops (e.g. if a tap is opened) then the pump runs and tries to re-establish the set pressure. This single pressure switch works for both hot and cold systems, as the the hot water heater is fed off the cold supply.
The pressure should be locked in the pipework by a non-return valve (NRV). These are usually incorporated into a single unit with the pressure switch. Most pressure switches are adjustable, and you manufactureres should give you instructions on how to adjust them.
Under normal conditins a loss in pressure will occur when a tap is opened or possibly if a 'hot' water heater is turend off and the air cap in the heater cools and reduces its pressure, but if you have a leak (even a small one), the pressure will eventially drop enough to trigger the pump.
You can obviously look for joint leaks or dripping taps, but you can also have a faulty non-return valve at the pressure switch. If this cannot hold the pressure, some cold water will leak back past the valve into the cold water barrel, so you may have difficulty spotting it.
If you can definatley point to a leaky NRV, and the problem is not too frequent, then you probably do not need to worry too much about it, and to avoid the pump kicking in every so often by turning it off over night.
Del may have indicated the cause, however there are other possible causes:
From your description I think it is safe to assume you have a 'pressureised system'. This works by a switch sensing the presure in the coldwater pipe. If the pressure drops (e.g. if a tap is opened) then the pump runs and tries to re-establish the set pressure. This single pressure switch works for both hot and cold systems, as the the hot water heater is fed off the cold supply.
The pressure should be locked in the pipework by a non-return valve (NRV). These are usually incorporated into a single unit with the pressure switch. Most pressure switches are adjustable, and you manufactureres should give you instructions on how to adjust them.
Under normal conditins a loss in pressure will occur when a tap is opened or possibly if a 'hot' water heater is turend off and the air cap in the heater cools and reduces its pressure, but if you have a leak (even a small one), the pressure will eventially drop enough to trigger the pump.
You can obviously look for joint leaks or dripping taps, but you can also have a faulty non-return valve at the pressure switch. If this cannot hold the pressure, some cold water will leak back past the valve into the cold water barrel, so you may have difficulty spotting it.
If you can definatley point to a leaky NRV, and the problem is not too frequent, then you probably do not need to worry too much about it, and to avoid the pump kicking in every so often by turning it off over night.
Agree, but some vans don't have NRVs and another possible cause of such short term running is leakage from around the connection to the submersible pump. The Carver unit with the cylinderical filter element is prone to craks due to over-tightening of the filter unit and thiese allow slight leakage. Look at the outside connection and see if these is any leakage from this even when the pump is not running - then run the pump, when any leakage will be more obvious.
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