DIY water system forced drain down (1 Viewer)

[bunter492]

Here we go - Retains existing 12mm pipe diameter (and probably some are the very same parts in the flo kits - cost me £13 total (although I already had one of the hose connectors - but they are two a penny at the markets anyway) I have lined them up but sorry pic is a bit blurry - you should be able to work out the parts. The bit of pipe is standard plastic 15mm as is the push fit at the top

 

[pappajohn]

Instead of fitting at low level and blowing water out the taps it may be better fitted below a tap and blow water out the drain valve/tap at the lower point.
Residual water tends to sit low down in the system.....why try to push it uphill to expelled it when pushing it downhill is more effective and should remove it all.

 

[Enword]

I've been reliably informed that the schrader valve will be happy to be in water permanently and thus the black isolation valve is not needed at all!

That's right I fit them in alloy racing radiators when I make them,they last for years.

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[bunter492]

Pappajohn - excellent point and I thought that at first before my first disaster :-( - after all, if taps were left open and a low point drain was used - how on earth would any lying water anywhere freeze up and cause pipes to crack with the expansion room available due to the taps being open? But they surely do - and many have the repair bills to prove it.

OK my theory - I think the relatively small bore plastic tubing coupled with the construction of MH taps and appliances may be the culprit.... freezing water does not always take the expected "easy way" as it expands and as it becomes more and more 'sludgy' (ever left a beer in the freezer?) It clogs gaps, gathers in nooks and crannies and then expands further as it freezes and expands 'proper' as weather becomes really brass monkeys - and that = cracks. That is why blowing it out with air works. - Plunbed in so to speak as above described by Techno or quick and dirty with ebay drain down above

 

[Techno]

Because my van has a shower point in the garage it was always overlooked and not drained properly by me initially but certainly the first owner too. I suffered a bad leak in the cold pipe to that outlet due to several winters eventually destroying the pipe. The forced air system is flawless and thorough. How you achieve this is either at retail cost or improvisation and there's always more than one way to skin a cat

 

[John and Jo]

Just had a look at my set up and it doesn't look like I can get the tyre valve before the pump. Is there any reason why I cannot have 2 x shut off valve and then push the water through the system and then through the pump to the tank? See photo.

And what's the white gizmo to the right of the pump.

Cheers

John

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[JockandRita]

And what's the white gizmo to the right of the pump.

Possibly a water filter, or some pressure accumulator device, but if the latter, I would have expected it to be floor mounted.

HTH,

Jock.

 

[pappajohn]

And what's the white gizmo to the right of the pump.

A surge damper to prevent the water from pulsing as the pump does its job.
It has a diaphram inside, one side of which is under air pressure....usually around 9 or 10psi.
As the pump pulses the diaphram absorbs the excess pressure and smooths the flow from the tap.
For it to work correctly the air pressure needs checking and topping up, via the inbuilt shreader valve, periodically.

 

[John and Jo]

Thanks pappajohn ...does it drain when the system is drained or does it hold water? How does this checking of air pressure and topping up work?

Cheers

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[JockandRita]

A surge damper to prevent the water from pulsing as the pump does its job.

Apart from the make, what's the difference between that and a pressure accumulator John?

Cheers,

Jock.

 

[OldAgeTravellers]

Thanks for starting this thread Andy @Techno100, I have always just blown down the taps with my mouth and been happy with that and no problem so far. But I had a spare car valve so bought a 3/4 bsp brass tee and 10mm Cap which the valve just pulled through and locked. A bit of silicon for belt-n-braces then the two ends of an old washing machine hose. Didn't have a tap but I did have a non return valve I had used before to stop water pushing out of my tank air inlet pipe before I re-designed it. Fifteen minutes and job done after buying the tee and cap of course €5.85.
So compressor set to 1bar and work round the taps. I got over a gallon out plus probably the same running out of the trauma drain and about a pint from the loo flush which I had never managed to find a good way of draining. Left all taps open and air running through for about twenty minutes so should be totally dry now.
Not sure if the pump will pull through the non return valve but will see when I fill it up again.
So great suggestion producing a good result. I will probably blow it out each time we come back from a trip so as not to have stale water sitting in the pipes although as we have a Nature Pure we do put half a bleach tablet in the tank with each fill to keep any bugs out.
Steve

 

[JockandRita]

Am I right in thinking that many MHs, are not fitted with drain taps for each of the water systems? I don't remember any of our British built caravans having drain taps for the pipe work, only for the tanks
We have a fresh water tank drain plug, a Truma C auto dump valve, and an inline drain tap for each of the hot and cold pipe works.
Once they are all drained with taps open to allow air in, I just unscrew the shower head, and blow through the hose, but there is rarely anything left in the system by that stage.

Cheers,

Jock.

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[BFM14]

Can anybody help please. I would like to fit the parts to my Knaus Sky TI but can't find the pump or the inline filter is. I have searched all round the boiler etc.

 

[Baycott]

Can anybody help please. I would like to fit the parts to my Knaus Sky TI but can't find the pump or the inline filter is. I have searched all round the boiler etc.

I don't know about the Knaus but I think the pump and filter can be almost anywhere. In my AT Tracker they were under the oven
Try and trace where the noise comes from when you turn on a tap and that's where you will find the pump

 

[OldAgeTravellers]

It could also be a submersible in the tank or like Andy's built into a recess in the top of the tank so possibly under a seat. If it is external to the tank you can usually feel the vibration.
But regardless of where the pump is if you find the outlet from the tank you can fit the drain down system there.
Best of luck.
Steve

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[Techno]

I've just drained mine down this morning after an unexpected frost last night. The first real frost of this year in Leeds which is unusual as it's normally early to mid November, another sign that the seasons have slipped a month.
Anyway all was well after draining 90 litres from the tank and purging the lines. As last year I've left the system pressurised at 15 psi so that I'll know if I have a leak next time I call at the van.

 

[John and Jo]

My set of bag pipes ready to be installed. Do you use anything where the valve goes to seal it?

 

[Techno]

Not sure what that means?

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[John and Jo]

Where you push the schrader valve into the hose connector ...is that all you did? No sealant or anything.

 

[Techno]

The inner tube was the seal. I discarded the circular one.
I discarded the isolation valve too (the chrome bit on yours)

Didn't you read page one?

 

[John and Jo]

thanks

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[John and Jo]

fitted and tested. It just replaces the existing section of blue pipe so can easily revert back. Close one tap and the air goes thru the system, close the other and it should blow through the pump to the tank but it didn't work the pump way and just pressured up to 15 psi and cut the pump out. Not sure why (non return?) and didn't have time to find out. Other way it cleared about 1/2 a pint.

Used with a Ring Automotive RAC600.

 

[cyberyacht]

When I had a caravan that drew water from an Aquaroll, I just connected a foot pump, pressurised the system and opened each tap in turn. Since switching to moho's, I haven't done anything other than draining the waster tank, boiler and a quick blow down the shower pipe. Fortunately living in "de deep south" we don't get much in the way of frosts. If it's clear enough for frosts, the sun usually warms the van up to keep everything above freezing.

 

[Pausim]

Can anybody help please. I would like to fit the parts to my Knaus Sky TI but can't find the pump or the inline filter is. I have searched all round the boiler etc.

I think my Knaus had a submersible pump in the tank under the seat.

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[BrianS]

Great thread and worth re-visiting as drain-down time is almost upon us!