DIY: How to Fix Water Pump in Your Caravan
There are a variety of service issues that can arise with your caravan’s water pump that the guys from The RV Repair Centre give some advice.
Most vans have a little 12V water pump that draws water up from tanks below the floor and pushes it up to the taps and shower head inside the van. The pump has a pressure switch that controls the pump turning on and off. When you turn on a tap, the pressure in the water lines drop triggering the pump to turn on. When you turn off the tap, the pressure in the water line increases and the pump turns off.
Reduced water flow - clogged inlet filter
The pump has internal moving parts that can jam if debris in the water gets inside the pump. To protect against this there is a small screen type filter on the inlet side of the water pump. This filter can become clogged restricting flow to the pump. If you have reduced water flow from your taps, cleaning the filter may fix this. If the filter becomes very clogged it may damage the pump.
Inlet filter cleaning process:
It may be necessary to remove the pump to access the inline filter. If so, follow the pump removal instructions further down in this article. If not, simply turn the pump off at the switch and open a tap to relieve pressure in the system before accessing the filter. When finished, turn on a tap and the pump switch to clear air from the water lines.
1. Loosen the inlet filter housing and remove the inlet filter
2. Inspect the inlet filter for clogging and rinse under a tap to clean
The pump runs with all taps turned off
You may hear your pump running (and possibly switching on and off) with all taps turned off. This may be caused by a leak in your plumbing system. A leak is the same as turning on a tap which causes a pressure drop triggering the pump to turn on. It’s kind of a good thing as the pump acts as a “pseudo warning system” for the leak and there is actually nothing wrong with your pump. The challenge though, is to find and fix the leak in your plumbing lines. We don’t cover repairing leaks in this article but here are some tips on identifying them. Conduct a search by crawling under the van, and also looking in the various accessible cavities such as inside cupboards. Look for a squirt or a drip or even a fine mist that could be coming from a fitting or the pipe. If you can’t find the leak, it may be in a part of the system hidden from sight. In this case, look for any signs of dampness that may appear in furniture etc. If you suspect you have a hidden leak you are likely to need some professional help.
Sometimes if the inline filter is not installed and sealed correctly, the water pump will suck air. This will also cause the water pump to run and then stop, repeatedly. This can be corrected by improving the seal on the inline filter with fresh plumber’s tape.
The pump does not start
There are three main reasons the pump may not start. 1. There may be a loose electrical connection to the pump. Simply check connections and refit or retighten as necessary. 2 The pressure switch may need adjusting so it kicks in earlier. Refer to your manual (hard copy or search online) for the procedure specific to your pump. 3. The pump has failed and needs replacing.
Pressure switch adjustment process:
1. Your pressure pump may have a pressure activation adjustment
2. Refer to your manual for instructions specific to your model
Pump replacement process:
1. Turn off the pump at the switch
2. Turn on the tap to relieve pressure in the water lines
3. Disconnect the positive 12V terminal
4. Disconnect the negative 12V terminal
5. Note - an inlet filter is usually attached to the suction side of the pump
6. Loosen the nut connecting the water line to the inlet filter
7. Disconnect the inlet water line
8. Loosen the nut connecting the water line to the pump outlet
9. Disconnect the inlet water line
10. Remove the screws holding the pump to the floor
11. Remove the pump
12. Fit the inline filter to the suction side of the new pump
13. Use plumber’s tape to create a seal
14. Screw the filter on being careful not to overtighten
15. Install the new pump in reverse order to removal of old pump
16. Turn the pump back on at the switch and turn on a tap to clear any air from the line
IF IN DOUBT, CONSULT A PROFESSIONAL
Improper maintenance can lead to injury, death or property damage. Maintenance work of this nature should only be undertaken by people with suitable competence. Information provided is general in nature, not comprehensive and should only be taken as a guide. Individual discretion must be exercised and persons undertaking described tasks do so completely at their own risk. Publishers and creators of this content accept no responsibility for loss or damage.
Thanks to Andrew Phillips and the team from the RV Repair Centre for their assistance.