No water flow into the van?

We are currently at a Caravan Park with very low water pressure, in fact so low they actually recommend using their water to fill your tanks and use your onboard pump for showers!

Well ours worked fine the first day, though yes, low on pressure.

Well the next day all of a sudden we had no water pressure, or rather, no water all! I presumed there was something wrong with the supply as I had only 10 minutes earlier filled the kettle for a cuppa.

A few quick checks and verified the water pressure was still there and working fine, it was a problem within he van. Knowing what it would most likely be, I took a lump of timber and knocked the water pressure regulator and one way valve a few times to see if it would come good – no go.

So time to check the valve. On our van the unit is located at the water inlet, and is a 350KPA pressure regulator and one way valve. This stops high water pressure caravan parks from bursting your internal pipe work and water heater, something you definitely do not want to do. It also features a one way valve to allow the water to come in from the park, but when unplugged and you run the pump from your tanks it stops the water pouring out.

To remove ours, I first removed the clamps holding it to the frame, then I unscrewed the black fitting from the end running into the van. I was going to removed the pipe from the push connector, but it didn’t want to come out easily and I wasn’t in the mood to force it.

Once it was out, it required 2 x 1in spanners (shifting spanner worked well) to unscrew the two halves, using the spanners where indicated by the red arrows. Once cracked loose, it could be easily unscrewed by hand the rest of the way. It’s not spring loaded when you unscrew it either so bits wont go flying everywhere.

Now its in half, pull out the spring and the centre tube it holds in place (green/yellow arrow section). The red arrow in the first picture below points to the one way valve holder, the green points to the one way valve itself, the blue arrow is pointing at the pressure reduction system. Holding that green section upwards the in the second and third photo we are looking at the one way valve system, with the red arrow pointing at the valve itself. The middle photo shows the valve closed, the last photo shows the valve open. Ours was stuck closed and I had to push a rod gently up from underneath and then it clicked and popped open. It is spring loaded and should close again on its own. Now I can blow through from the thinner end and open the valve (before I tried and no way it would budge).

Water spurting out: If you have water pour out the inlet when you run the pump, your one-way valve is stuck open and most likely some dirt or gunk caught in the valve. Make sure you always run a filter on the inlet.

No water coming in: When low mains pressure in the park but no water at all coming into the van – this is what we had and the one way valve was stuck shut. Sometimes a quick smack will jar it open again, sometimes not.

Low water pressure in van but Mains OK: We also have this issue.. Looking at the Yellow arrow below, this is the section that slides through two o-ring inside the light blue arrow section, while the O-rings highlighted with the green arrow slides through the tube the red arrow is pointing to. You will notice the yellow arrow section of mine is dark and discoloured. This is gunk, pitting and corrosion on the brass from the last 5 years use and is restricting it sliding smoothly through the tow o-ring in the blue arrow section. Likewise, inside the where the red arrow is pointing the tube will also look the same. The water pressure pushes the piston against the spring and pushes it through the o-ring at the blue arrow, the spring trying to hold it open. The other end of the piston also has 2 o-rings (green arrow) that slide inside where the Red arrow is pointing. The harder the water pressure the more it pushes against the spring and closes off the water supply. With the corrosion on the piston (yellow arrow) and in the main tube (red arrow) stopping it sliding easily with the spring pressure, the water pressure pushes it it in against the spring to reduce pressure but but the spring is not able to push it back open due to the discoloured sections stopping it sliding back out easily and water pressure stays low. I have polished this up the best I could on the road with limited equipment and it has improved he water flow but it’s still not perfect (EDIT: I realise now I did not polish up the the other end where the red arrow is pointing – next time it annoys me I will do that end too). I will try again another day when I can grab some fine emery paper, otherwise I may have to buy a replacement (I may actually buy a replacement and fit that then clean this one up for a spare when I have – $74 at the local caravan supply place to me in Darwin, about $65 online).

NOTE: I have read online recommendations to stretch the spring out to improve the water flow. DO NOT DO THIS.

The spring is what gives the unit its water pressure rating and if the spring weakens over time, yes it will decrease the water pressure, not increase it and cause damage, so it can not suddenly increase pressure and burst your pipes, joins or hot water tank. In other words it is designed to slowly reduce pressure if anything fails. So please, DO NOT STRETCH THE SPRING! If you believe the spring is deformed or damaged REPLACE THE WHOLE UNIT.

Reassemble is the reverse of pulling apart, however, clean the surfaces first (a quick wipe down) then referring to the first photo above use some edible grade oil (spray olive oil is perfect) on the rubber with the green arrow, the shaft with the yellow arrow and the rubbers inside where the blue arrow is pointing. push together and then screw back together. Nip the last bit up with the spanners, not too tight as it has a rubber o-ring seal.

Now clean off the black pipe fitting hack on the van and apply a few wraps of fresh plumbers tape (wrapping it in the same direction you would screw a nut on) then screw it on. Ensure the pipe fittings are pushed in all the way and test!

Any questions or comments welcome!

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1 Response

  1. Dave says:

    Just had a neighbour in the caravan park at Kununurra with very low water pressure problem and while he was testing and scratching his head I was able to quickly point him in the right direction and he was back up and running with little fuss and no expense. Just a good clean and lubricate and all working well again.

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