Winter water tank emptying air pressure system

[the1andonly]

There have been a number of threads advocating the use of air presure to reduce the amount of water remaing in the system after draining. Technos article shows an example of how to fit a tyre valve into pipework. This is even in my rapido hand book as a reccomendation (.5bar max)
My problem/ question is which of my accessable lines should i break into.
The tank is under a seat passenger side (rapido 604ff)
2 pipes go from either side of the pump down left under the floor in the shed (you cant call it a garage).
A 3rd accessable pipe is the overflow that comes up and over the tank down the rhs and exits near the other drains. It is not possible to reroute behind the tank. The sensible but longer route would have been down into the floor void with the other2.
The filler to tank is not accessable.
The drain taps (main 20l in tank and dump valve) are just accessable under the floor (trap door) in the shed .
Which side of the sureflo pump is feed/return filter side?
Thanks for any advice.

 

[pappajohn]

I would fit just after the pump.
The pump, by design, effectively has a non return valve so air will only pass into the pipework and boiler, not the tank.
Open taps, admit air.

 

[TheBig1]

the easiest way is unscrew the shower head, open each tap, hot and cold and blow down the pipe with the drain open

 

[Wagoneer]

I've fitted an off-the-shelf product for pressurising the system and getting rid of excess water via the taps.

The T-piece is fitted BEFORE the pump. Prior to the T-piece, is fitted a stop valve which stops air going to the fresh water tank during the procedure. I suspect a non return valve would serve the same purpose.

So, basically, locate the cold water feed from the tank to the pump and insert your pressurising device into that.

Just make sure your boiler dump valve is closed when pressurising. Also, if your toilet flush is supplied via the fresh water tank, make sure you drain that as well.

Edit: or you could adopt @pappajohn method on the basis that the pump has a non return valve.

 

[Feltwell]

I confess I just tend to make sure the dump valve on the boiler is open, that the pump has run until it's dry and got as much through the taps as possible, and leave all the van taps and the shower control open. It's survived each winter like that with no problems, even through the "beast from the east"!

I can't believe I'm the only one taking this lazy option......

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[the1andonly]

I can't believe I'm the only one taking this lazy option......

I suspect not the only one, but the 3 pieces of evidence in front of me sugested it may not be a bad idea.
1. The info and threads on here
2. RAPIDO sugest it in thier hand book
3. When I picked it up in March thevan all ready had a leaking shower ( replaced)

Thanks to all will insert after pump.

 

[DP+JAY]

I use an electric air pump of the type for blowing up air beds, inflatables etc. Fairly high volume but very low pressure so no risk of blowing a seal or damaging the boiler.

 

[wingman]

IF YOU WANT TO AVOID THIS.........

DRAIN THE SYSTEM PROPERLY!!

PIC 1. Is a moulding of my filter housing, in ice!
PIC 2. Is an icicle from my kitchen tap!

I live in the Saaf East too. Not known for its low temperatures until, that is, the Beast from the East struck last year.
I religiously drain down each winter with a Floë system. Last year, a combination of events prevented me from doing so. Among the excuses, I was going to use the van.
All I could do was to leave it to thaw out naturally. Luckily, no damage was done; not even to the joints.

As an aside, blowing down the pipes is unlikely to shift all of the latent water. Relating back to my Paramedic days, I was taught that normal lung capacity, minus residual air, minus ‘dead space air’ (i.e. air in the trachea, bronchi, etc) would not have enough pressure to blow out all of the water from a normal MH water system. This is why you can’t have an overly long snorkel tube when swimming. If you did, you would just extend the dead space air, not be able to push water out of the snorkel tube, refresh your lungs with oxygen and in effect, you’d asphyxiate!

Yes, blowing down the pipe will get some out and give a pleasing gurgle, but blowing alone will not remove all water. There are always exceptions and I daresay that some have been lucky, but as a general rule, blowing doesn’t work totally.

The best way is to pressurise the system, either with an off-the-shelf gizmo, or by using one of the systems documented by funster inventors!

 

[Zigisla]

Although I do not "Winterize" the water system as we use the MH all year, I do open the boiler dump valve and open all the taps without power on, so the system just dumps the boiler and most of the fresh tank. A friend of mine - caravaner , does the same, but always blows up a normal balloon and releases the air through the Shower hose to get the last of the water out. He has never had burst pipes in many a year.

 

[the1andonly]

Yesterday added this to system after pump the n fitted a tyre
pump and run for 30mins no extra water. Thought i'd drained it well. So today removed the tyre valve fitting and used an airbed type low pressure pump (as advised here some where) again 30 mins. Open tap instant gurglings both kichen and shower. Outside to shed (garage?) Close drain taps and dump valve, 20 mins of gurgles . Open dump valve and voila l'eau. Wel a tiny amount but still enough to stain driveway.
Thanks for all assistance

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[Wagoneer]

The OP's system would appear similar to my off-the-shelf system.

I use a footpump and bring the pressure up to 15psi (1 bar). Then open one cold water tap (usually the one furthest away from the pump) and dispel the water. I may need to do this a few times until no water emerges (only the hissing of air).

This is then repeated on all taps, including shower and cold water feed to toilet flush. Then do all the hot water taps and shower.

If the system doesn't hold the pressure initially with all the taps closed and dump valve closed....you've got an air leak in the system somewhere. This is a good check on the water tightness of the system.

I don't fully understand the OP's method of running the pump for 30 minutes and waiting for the gurgling.

 

[tonka]

I confess I just tend to make sure the dump valve on the boiler is open, that the pump has run until it's dry and got as much through the taps as possible, and leave all the van taps and the shower control open. It's survived each winter like that with no problems, even through the "beast from the east"!

I can't believe I'm the only one taking this lazy option......

My same procedure..
When i know the van will be stood a while and going to be very cold, I also unscrew the pipe where the filter goes into the pump.

 

[the1andonly]

My method is not a method more a stumbling in the dark. I cant remember if one of the valves and been left open but no noise or water 1st time around, or build up of pressure. It was only with the air bed pump that any gurgling or movement happened. Next time i will try to remember your method. No air leaks were felt from accesable joints.