Vanmaster Association Enhancing the Enjoyment of Owning a Vanmaster Caravan

Draining with Floe

Hi Everyone,

When I blow air through the water system during drain down I bypass the tank and on board pump by opening the bypass valve. I do this because I am worried that letting air into the tank and through the pump may cause damage to the tank float system and the pump diaphragm. Has anyone used the air system and allowed the air to fill the tank and pump without problems,


9 Responses

  1. Edward Sellars Edward Sellars

    Hello Keith,

    In my Vanmaster the on-board tank is vented so that as it is filled with water the air escapes otherwise the tank will be pressurised. The vent also acts as an overflow if the float does not close the solenoid valve. It is therefore not possible to drain down without opening the bypass valve.


    • Keith & Stella Hartley

      Hi Edward, When draining down I normaly open all the taps and the water heater and tank drain valves and the water drains out without a problem but I have now started using a modified version of the floe system which I have placed info on in the tech section.To use this method I close all the outlets and open the bypass valve,this allows air to be pumped into the system without entering the tank and passing through the pump.The people at Floe have told me that the air can be allowed to pass through the tank and the pump thus flushing out any residue ofv water left in there.To do this it would mean blankking off the overflow in the tank otherwise the required pressure of 15psi cannot be achieved. All this said the floe people are assuming that the water tank does not have our Vanmaster solenoid valve method of filling fitted. Therefore what I am trying to establish is if I fill the system with air including the tank and pump will the air pressure in the system cause any damage to the tank float system and pump diaphragm bearing in mind the air is 15psi where water pressure is pumped at 20ps my air system works fine but getting out the bit of water left in the tank and pump will ensure better protection from frost.
      Thank you Keith.

  2. Keith & Stella Hartley

    I know of course that I can get the air into the tank and the pump my switching on power to the solenoid valve to open it

  3. Edward Sellars Edward Sellars

    Hello Keith,

    I would not advise pressurising the tank in the way Floe had suggested. I know that one member had the air vent/overflow pipe kinked so it was blocked and when he started to fill the tank it became pressurised. The seals at the top of the tank where the water level gauge is fitted ruptured and air with water were sprayed out over the electrics in the bed locker.

    There are cleaning and purifying chemicals that can be used in tanks without having to pressurise the tank.

    A point that was highlighted by Alde at the Association event when they visited the Alde factory was to ensure that any solution used in the water system is suitable for stainless steel or it could affect the Alde boiler and pipework if pumped through the system.


    • Keith & Stella Hartley

      Thank you Edward I will take that advice and leave the tank and pump alone. I have found that after normal draining down I close the bypass valve and leave the solenoid valve open and then
      I can blow any residue of water out of the pipes leading to the tank from the inlet socket with my mouth to the air pipe that I have fitted then I open the bypass valve and use the air pump.


  4. Richard Wallis

    Hi Keith

    Two points. First, we had a problem with stale water and found that the drain pipe from the tank was routed over part of the chassis. Whilst the syphon effect drained most of the water it left a small quantity of residual water which tainted fresh water. I resolved the problem by re-routing the drain so that it is lower than the bottom of the tank and installed a manual drain valve controlled fromm the side of the van. It solved the problem and we have not had any reoccurrence. We use the water straight from the tank without any filter but we always boil water or use fresh water for drinking.

    Second, I have a shut-off valve after the pump then the floe connector to blow out the residual water in the hot/cold water system. However, I always open the shut-off valve for a minute or so to pressurise the pipes from the tank. Having had that piece of pipe freeze was the reason we bought the floe valve.

    Cheers Richard

    • Keith & Stella Hartley

      Thank you Richard we also use water from the onsite tap which we put in plastic bottles. I have replied to info from Edward and in it I mention the bypass valve,I don;t know if all Vanmasters are plumbed the same but mine is as follows,the water enters the tank from the inlet socket via the solenoid valve and just before the valve there is a “t” piece that routs cold water pipe to a shut off/bypass valve which is closed during normal operation so water has to enter the solenoid. When the bypass valve is open and the solenoid valve is not used water then passes to the taps and water heater thus bypassing the tank and on board pump. This is useful if there is a fault with the pump and you connect direct to the mains tap onsite as I do on service pitches,it’s O.K but water pressure is greatly reduced.

      I have connected my air system to the water pipe close to the inlet socket by cutting the pipe and insert an equal t piece, I have then branched off the t piece about 2 inches and put on an elbow facing to the rear of the van and then a none return valve so water cannot get up the air pipe when the system is refilled.I have then inserted a piece of water pipe to which I can connect my pump when I require to blow air through.This is a cpy of the £200 Floe Induratec system and only cost about £25 for the push fit components and a metre of pipe and its very efficient.

      So my way of doing the drain off is to open the tank and the water heater drain valves and the taps in the usual way and then open the solenoid valve and blow through then close the solenoid the tank drainers and taps and open the bypass valve and use the pump as described in the Floe instructions, it works a treat even for the toilet.

      So thank you for all the info and after this long winded reply for which I apologise but I thought was needed I will do as Edward has said and forget about the tank and pump and I will look at the tank drain pipe as you have sugested and otherwise carry on as I have been doing. Regards Keith.

  5. Bill & Aubyn Arbuckle

    Hi Keith,
    We have a 2005 vanmaster twin axle ( 620 ),we did try blowing air through the pipes when preparing winter, if you dont bypass
    the internal pump the air can damage the gasket.
    We also had the gasket leak when attached to mains supply for the water, now fitted a float on water barrel !!!!. We are slow learners,WJSA

    • Keith & Stella Hartley

      Thank you your points are welcome,I also have a float system in case my direct feed from tap to van fails,thanks again,Keith.

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