To drain down or not

[Richtee180]

I'm on a seasonal grass pitch, last year I opened the yellow dump valve and drained down each time I went home, then closed it upon my return and refilled the boiler and pipes, the splatter out of the taps made me jump every time.

But upon realising that not all of the water actually leaves the system am I best not to drain down each time, but just run the taps a bit on my next visit.

I wondered too if draining down and letting it hit the turf could create a level of dampness under the van.

 

[ProfJohnL]

There are two reasons why draining down is important. The first is if the temperature is likely to close or below freezing, if the caravan is not in use the water in the pipes may freeze and damage the system.

The second reason is to remove standing water which in hot weather may become a breeding ground for a number of bacterial or mould growths which may be hazardous to us.

The pipework in a caravan differs to that at home, as its generally more exposed and may be affected by extremes of temperature that can arise inside a caravan.

he second reason is why it is recommended that periodically you should sterilise your caravans pipework.

WHen draining down you should take care to make sure its as dry as possible. You can get kits that blow air into the pipe system to help ensure water is full expelled.

If you don't drain down you run the risk of blown joints or fittings, or exposure to contaminated water.

 

[Dustydog]

And drain down the toilet flush tank. Failure to do this may result in a cracked ruined pump.

 

[Andy Norfolk]

I always drain everything down when I leave a site. I also leave the taps open so that the shaking of the van on the tow home gets residual water out. I have a friend who charges the water in his caravan at home before he leaves on a trip to make it easier when he sets up on a site.

 

[Richtee180]

I always drain everything down when I leave a site. I also leave the taps open so that the shaking of the van on the tow home gets residual water out. I have a friend who charges the water in his caravan at home before he leaves on a trip to make it easier when he sets up on a site.

The thing is I don't tow, it stays on the same pitch all year round.

 

[ProfJohnL]

The thing is I don't tow, it stays on the same pitch all year round.

That is why I mentioned

"kits that blow air into the pipe system to help ensure water is full expelled."

 

[Martin_E]

And an important note for Alde users who have seasonal pitches is it’s very important to turn pump off, open taps and let about 20-30 seconds of water out of the drain valve at least once a month to stop hammering (this damages the boiler) as it will rejuvenate the air cushion in the heater

 

[IanB1485]

As ice forms it expands ( forming crystals which interlock) and only if the water pipe/fittings are at pressure will it cause bursting. if not at pressure then as the ice forms it will follow the path of least resistance i.e along the pipe not sideways to burst it. Also ice is only 9% greater volume than water so if your system is 90% empty with all taps open then it will be OK. Its a complete myth that it has to be completely dry to be safe. People think it must be like the incredible hulk swelling and bursting out of his clothes (funny how the trousers tops always survived intact) funny also how water tanks in people lofts ( before combi boilers) survived those harsh british winters we used to get.The people who invented those blowdown kits just predated on people's lack of understanding of the basic principles of physics.Do you drain your cars' windscreen washer bottle if a big overnight deep freeze is expected?

 

[otherclive]

As ice forms it expands ( forming crystals which interlock) and only if the water pipe/fittings are at pressure will it cause bursting. if not at pressure then as the ice forms it will follow the path of least resistance i.e along the pipe not sideways to burst it. Also ice is only 9% greater volume than water so if your system is 90% empty with all taps open then it will be OK. Its a complete myth that it has to be completely dry to be safe. People think it must be like the incredible hulk swelling and bursting out of his clothes (funny how the trousers tops always survived intact) funny also how water tanks in people lofts ( before combi boilers) survived those harsh british winters we used to get.The people who invented those blowdown kits just predated on people's lack of understanding of the basic principles of physics.Do you drain your cars' windscreen washer bottle if a big overnight deep freeze is expected?

My cars winter screenwash is good for -15 deg C at least. Even if temperature went below it wouldn’t freeze solid. But I agree that the blowdown kits prey on people’s uncertainties.

 

[Buckman]

Those kits to blow water out of the system are generally a total waste of money and time. Firstly make sure that the filter is removed as that will hold water. Then open all the taps, remove the shower head and blow down it. Job done!

If there is still some water left in the system even if you use the kit, if that water freezes and expands, it has room to expand and should not damage anything. In well over 30 years of caravans we did the above and no issues.

 

[Richtee180]

That is why I mentioned

"kits that blow air into the pipe system to help ensure water is full expelled."

I was referring to Andy Norfolks post.

 

[Hutch]

I'm on a seasonal grass pitch, last year I opened the yellow dump valve and drained down each time I went home, then closed it upon my return and refilled the boiler and pipes, the splatter out of the taps made me jump every time.

But upon realising that not all of the water actually leaves the system am I best not to drain down each time, but just run the taps a bit on my next visit.

I wondered too if draining down and letting it hit the turf could create a level of dampness under the van.

I think it all depends on how often you use the caravan, if it was every weekend then I would NOT drain it down and just give the taps a longer run as you mentioned.
But is your van plugged into mains water direct, then it is basically a sealed water supply, but if you are using an Aqua roll and float valve you might get Biofilm on top of the Aqua roll water. Aqua roll do a filter that goes in the Aqua roll tub, supposed to stop that. Never known anyone to use one though.

 

[borderbilly]

I always drain everything down when I leave a site. I also leave the taps open so that the shaking of the van on the tow home gets residual water out. I have a friend who charges the water in his caravan at home before he leaves on a trip to make it easier when he sets up on a site.

What does he charge the water with

 

[Buckman]

I always drain everything down when I leave a site. I also leave the taps open so that the shaking of the van on the tow home gets residual water out. I have a friend who charges the water in his caravan at home before he leaves on a trip to make it easier when he sets up on a site.

Probably not a very wise idea filling the system before leaving home as that immediately adds +10kg to the nose weight plus I don't think the hot water tank has baffles in it. If you are going on holiday why rush anything? LOL!

 

[Andy Norfolk]

Probably not a very wise idea filling the system before leaving home as that immediately adds +10kg to the nose weight plus I don't think the hot water tank has baffles in it. If you are going on holiday why rush anything? LOL!

Yes I agree. I did find it strange, as the same friend advised me to drain down for the journey home. Seemed a bit illogical when he fills the systems for the journey out.