Welcome to Manins motorohome project

Water Management

Water is pumped by a 12 V pressure pump from the fresh-water tank through a non-return valve to sink, basin, shower and toilet. It also goes via a pressure reducer and safety valve to the hot water service. Hot water passes through a tempering valve to the sink, basin and shower.

When the A'van is connected to mains water, water passes from the supply hose through a pressure reduction valve and non-return valve to the house plumbing.

Water Tanks and Levels

The fresh water tank is a 62 L black plastic Hume product with all connectors at one end. The water level is monitored by a rod-type sensor fitted to the top of the tank. It is a Schaudt M 400. The level is displayed on the Elektroblock Control Panel.

Schaudt M400 water level indicator

The 71 L grey water tank is purpose built for the Applause, welded up from aluminium sheet. Brass one-way flap valves are fitted to the drains from the kitchen sink (under the vehicle) and the shower (at the inlet to the tank). The drain from the wash basin is looped to prevent odours entering the house. The water level is monitored in the same way as for the fresh water, but the sensor rods appear to be cut short, so that if it were to work properly, the first level indication would be somewhere near half full.

Experience has shown that the freshwater level indication in the A'van Applause is very inaccurate, possibly due to the shape of the tank. A display of 25% full is in reality about empty. The greywater level indication only works some times – unless the tank is regularly cleaned using a product such as "Actizyme" from Coles the sensor becomes contaminated by grease.

Issues

  • In operation the pump made a lot of noise due to the rigid plastic piping connecting the pump knocking against the surrounds.
  • At low delivery levels the pump tended to pulse rapidly, making a disconcerting noise.
  • There was no filtering of water into the pump.
  • The water tank inlet hose reached higher than the inlet fitting on the outside of the A'van, making filling from a container very difficult.

Plumbing Layout

All pressure lines are 12 mm blue (cold water) and red (hot water) semi-rigid plastic pipe, joined with John Guest push-on fittings (see here for how to use these). The revised plumbing layout is shown here (click for enlargement), and the changes are discussed below.

Schematic of plumbing layout in Applause (60 kB)

The Water Pump

shurflo2088_parts.gif

This is a SHURflo 2088 classic series #2088-422-444 (Aftermarket) (...-144 OEM), a 3 chamber 12 V diaphragm pump. It is self priming, and can run dry. A built-in check valve protects the pump against high pressure in the water line (up to 200 psi).

The rated flow is typically 7.5 litres/min (2.0 USgpm) at 1.4 Atm (20 psi). Maximum current is 7 Amp.

The port threads are 1/2"-14 NPSM (US National Pipe Straight Male). These are NOT the same but are very close to 1/2" BSPM (British Standard Pipe Male). A'van had used the correct (US) John Guest adaptors to plumb in the pump.

Improving the Plumbing

pump_detail.jpg

As supplied, the outlet of the pump went directly to a corner connector and a set of brass connectors for a one-way valve fitting. This was not a good setup and may have contributed to excessive noise from the pump. I replaced a lot of this rigid pipework with stainless steel braided flexible hose. However these have connectors with BSP threads. On the pump inlet connection the chosen flexible hose has a gentle bend in the stainless steel pipe; using teflon tape and Hawkins Paste, I have screwed this onto the pump directly. I was careful to ensure none of the tape nor paste entered the piping. For the outlet, the US JG adaptor is retained, and a 1/2" BSPTM to spigot connector is joined to it. The braided flexible tube then screws into this latter adaptor.

The reinforced flexible stainless steel hoses on inlet and outlet eliminated two corner connectors and allowed removing the one-way valve to connect directly to a remote existing "T" connector. The inlet steel hose has a gentle right-angle curve built in so as to clear the vehicle wheel arch.

In doing these changes, JG 12 mm tube inserts were fitted to all cut ends (as was already done by A'van for their joints) and JG 12 mm locking clips were added to all hot water and some cold water pipe fittings.

Inlet Water Filter

A "hot water strainer" from FreshlySqueezed Water Company was installed near the inlet of the pump. The intention is to catch particles, rubbish and gum nuts!

inlet water strainer

Accumulator Tank

The pulsing of the pump at low flow rates was eliminated by installing a SHURflow accumulator tank in the cold water line. The precharged pressure of 20 psi (max 125 psi) was not changed, but the installation allows easy monitoring of the tank pressure, and a bicycle pump is available to recharge the tank.

Hot Water

The Truma B14 water boiler uses LPG or mains electricity and is controlled by two switches on the wall next to the bed, and either or both can be ON at the same time. On LPG, the rated heat output is 1500 W with a gas consumption of 120 g/h. On mains electricity the rated input at 230 V is 850 W (3.7 A). (If powered by the 1500 W inverter, the load would be about 66 A. This may be feasible for brief periods when there is excess solar energy available during the day.)

Water Heater ON

The switch for operation on LPG is grey on a grey background and it was hard to see whether it had been left on. I have added an LED that lights whenever the LPG operation switch is ON.

Truma_ON_circuit.jpg

Measurements on the switch circuit show a voltage a little below supply level at the 70° switch pin whenever the switch is active (at either the 70° or 60° positions). At the 60° switch pin the voltage is initially lower (2 V lower) and rises when switched to that position.

water_heater_on-led.jpg

Adding a 3 mm orange LED and 1 kΩ resistor as shown in the coloured part of the circuit diagram does not load the circuit, and does provide the required Heater ON indication. See the photo (click for larger version). The LED is positioned at the top of the switch surround.

(As shown in the circuit diagram, there is also a red LED positioned at the lower left of the switch surround that activates if the heater goes into fault on LPG.)

The Tempering Valve

The tempering valve mixes cold and hot water to maintain a lower maximum temperature at the hot water outlets. It is a NEFA TMV15, supeceded by the NEFA TTV15C. The valve includes integral line strainers and non-return valves on both inlets. Popping the plastic top gives access to the outlet temperature adjuster; turning the adjuster nut towards the hot water inlet increases the supply temperature.

Water Heater Vent Cover

The vent in the side of the van for the Truma hot water service had a "removable" cover that was supposed to be fitted when not in use - presumably to keep dirt and hose spray out of the vent and heater. The number of vans I have seen without this cover is testament to the difficulty and inconvenience of fitting it.

Initially I made up an aluminium plate to permanently cover the vent in the fashion of some other kinds of heaters. I also installed a piece of fly screen behind the vent wall fitting to keep out wasps and such. However, this cover caused the heater to misbehave when on gas — the combustion air intake took too much air from the combustion air exhaust and the flame weakened so much that the heater went into fault mode after some minutes.

So now I have made a cover plate that only blocks road spray entry. Maybe something better can be devised.

Filtered Water

Voyager filter set

So far I cannot find the space to add a dedicated fresh water tank. Regardless, drinking water is now filtered in the Applause to a standard able to remove Giardia and Cryptosporidium.

Because space is such a premium, I could not install standard 10" filter cannisters. Instead I opted for the more expensive, but high performance, dual filter arrangement called "Voyager" from Freshly Squeezed Water Co.. The filter unit is very compact and easy to install, coming with miniature John Guest fittings and adapters to 12 mm fittings. It was plumbed into the cold water line going to the kitchen sink using John Guest fittings left over from the replumbing of the water pump.

Each filter and its cannister are an integral unit that snaps into and out of position with a slight twist. A small tap isolates the filters when its time to change them or to store them in the fridge if they are not going to be used for a while. Because both the filter and its cannister are replaced when its time, there is no chance of transfer of bugs which might happen if just the filter were to be changed.

filter performance

A separate faucet in the traditional flick action style was fitted to the sink bench by drilling a 12 mm dia. hole and feeding the white pressure tubing under the bench to the filter unit.

Performance of the unit is impressive: the 12 V pump easily copes with the pressure drop, giving a good water flow rate through the filter pack, and the flick faucet is convenient to use.

Two 20 x 6 mm aluminium straps have been added to protect the filters from other things in the space under the bed, such as awning poles, boat oars and boat seats. The straps are sized to allow the filters to be removed.

Dec2013: It appears that the filter unit is no longer available, but replacement cannisters are.

Taking on Fresh Water

A dual lockable water filler is located over the offside rear wheel. A 10 m food-grade hose with snap-on fittings can connect directly to one of the filler points to supply water from the mains. A non-return valve and a 350 kPa pressure limiting valve in the line ensure a safe operation (see the layout diagram above). The water pump should be turned off when this connection is used, otherwise the pump tends to run when a tap in the Applause is on.

Alternatively, the hose with trigger nozzle is connected to the mains and used to fill the water tank through the other port of the dual filler, and the water pump does its job.

primus12vshower.png water_filling.jpg

If mains water is not nearby, available water must be bucketed into the tank. A large funnel with a bend in the throat can be used, but it is very fiddly and a rigid bucket is required. Instead, I use a Primus Camp Shower plugged into a cigar-lighter socket at the back of the van and running off the house battery. I discarded the shower head, and with the submersible pump at the bottom of the bucket of water, turn on the pump and direct the water into the tank filler.

  • A 15 L collapsible bucket is a good container for the water
  • But since it can collapse, a tensioning elastic strap is a good idea
  • The submersible pump needs to have silicone grease applied to the impeller shaft to stop rusting and seizing of the motor
  • Of course, the Camp Shower can also be use as intended — to take a shower.

Feb2011: The submersible pump in the Primus kit is rubbish and soon seizes up with rust. I have replaced it with a Rule 12 V 360 gph bilge pump from Whitworths Marine where it is occasionally on special for under $20. To fit the shower hose I inserted a 12 mm plastic joiner in one end and jammed the now-expanded hose into the pump outlet.

Sep2013: 10 litre plastic jerry cans that exactly fit the free space behind the passenger seat were found in Bunnings. We now can carry 82 litres of fresh water.

LINKS

Water in the Applause

water_containers.jpg

In addition to the 62 L of tank water, there are two 10 litre plastic containers wedged in a space behind the passenger seat.

water filter 
            fitted to inlet plumbing (80 kB)

The water filter is circled in this early photo, which also shows the rigid inlet piping

Pump with stainless steel
            inlet and outlet hoses (50 kB)

The inlet flexible hose (A) with gentle right angle. The outlet flexible hose now locates the non-return valve at the "T" piece (B) well away from the pump, and the outlet from pump (C)

Euroblock non-return valve

Orlando Euroblock PN40 DN10 non-return valve

the Shurflo accumulator 
            mounted in Applause (60 kB)

Accumulator tank (pressure vessel) mounted on wall of bed base in the cold-water line to the sink.

water_heater_on-led.jpg

The LPG switch for the Truma water heater now includes an ON indicator LED. The 230 V switch is to the right, and the controller for the Eberspächer diesel heater is below.

NEFA tempering valve

NEFA TMV15 tempering valve sets the delivered hot water temperature to ??

waterheater_cover(mod2).jpg

A spray guard fitted to the outside vent for the Truma water heater.

water filters (42.5 kB)

The "Voyager" water filter unit, with isolation tap, fits under the bed against the stove/sink wall. It is plumbed into the cold water line with John Guest fittings.

water tap (50 kB)

Water faucet with flick lever is fitted to the sink bench and is convenient to use.

filling_water_tank.jpg

Setting up the Primus Shower pump to fill the Applause water tank from a bucket