Draining down a caravan for winter storage

[Saxo Appeal]

Do we really need to completely drain down our Caravans for winter storage?

I can see some people use a pressurised tool to completly blast all the water out, but is it really required?

When you open the valves to drain, then open all the taps, doesn't the water pump and boiler drain down completely, and any water left in the pipes will bew settled?

At the last site I unscrewed the shower hose and gave a good couple blows which seemed to do the trick.

I mean there will always be some residual water left, so clearing it completely may be fruitless.

Then when the new season starts, flush it thoourghly with the Puriclean.

 

[Bluetonic]

Never used a pressure device to blow out the pipes.
I drain as much as I can by opening the yellow hot water valve, then take the shower head off and give a couple of really big blows down the pipe.
Leave all taps open.
Make sure to remember to empty the toilet flush (I know it's part of the freshwater system on some newer vans)
Move all the cushions/swabs away from the walls, open fridge door and all cupboards/draweres to allow airflow.
Make sure all food stuff is removed.

Be sure that the waste pipe bungs are closed to stop rodent ingress (ask me how I know)

 

[Paullus1959]

Yes, you do is the simple answer unless you are going to keep the caravan heated throughout the colder months.
I had a very close shave last Winter and I thought I'd drained down completely. I'd opened all the taps and the shower and then opened the main water drain taps. I always drain down fully before leaving a site anyway and leave all the taps open. So, I doubt there's much water left anywhere in the system after a few miles. However, for some stupid reason on this occasion, I had opened the mixer tap in the rear washroom fully in the hot water position instead of midway between hot and cold. I therefore trapped water in the cold water pipe which ultimately froze. Fortunately, I was lucky no joints were pushed apart and the tap itself survived. Lesson learnt.

 

[Mr Plodd]

This is a bit of a "Marmite" issue. Some will insist is absolutely essential to remove every last drop of water, and others will say that's not hecessary.

To my simple mind a bit of water left in a pipe isn't an issue. It can certainly freeze, but as it does so, because it has air all around it can expand into that air (because air can be compressed) The problem arises when a pipe is full of water with both ends "sealed" The water then expands as it freezes, there is no air in the pipe to be compressed as the water expands, so something has to give, be that a pipe or a joint.

Me? I open the yellow dump valve, along with all of the taps, after leaving a site. My theory being that all of the motion of the journey home will ensure any residual water finds its way to the dump valve and out of the system. Over the 20 plus years I have owned motorhomes and caravans I have never suffered a burst pipe or popped joint. So I reckon my theory has some reasonable credibility. Others will just say I have been very lucky for 20 plus years.

 

[ProfJohnL]

Certainly if a water container such as a water heater is left full, and it freezes the expansion of the water as it freezes can do serious damage to the appliance.

The Carver Cascade mk2 (horizontal tank) was particularly sensitive to being frozen, as the ice would jack the tank away from the main casting a little and displace the tank sealing "O" ring, or if it was more seriously frozen, the ice expansion could distorted the closed end of the tank, and it could also stretch or snap the internal tie rod.

But the more common issue is if any water remains inside any of the water systems Non Return Valves (NRV) which are often at almost the lowest points in the system, such as in the cold water input to water heaters, and pressure switches. Even with only a residual teaspoonful of water remaining in these valves, the expanding ice can catch the seal or shuttle inside the valve and distort or permanently damage the valve.

Thus it is quite important to remove as much water as possible. Whether you need to use a pressurised system will depend on the arrangement in your caravan.

I used to open all the valves etc as I left my holiday site, and by the time I got home all the jiggling caused by towing seemed to remove all water.

 

[toad a caravan]

Do we really need to completely drain down our Caravans for winter storage?

I can see some people use a pressurised tool to completly blast all the water out, but is it really required?

When you open the valves to drain, then open all the taps, doesn't the water pump and boiler drain down completely, and any water left in the pipes will bew settled?

At the last site I unscrewed the shower hose and gave a good couple blows which seemed to do the trick.

I mean there will always be some residual water left, so clearing it completely may be fruitless.

Then when the new season starts, flush it thoourghly with the Puriclean.

I don't know what type of toilet you have I have a Thetford C2.The holding tank if not already drained may need draining ,Gary

 

[Beardy]

After reading a few threads on this subject I went out and blew down the shower hose in my caravan with the taps closed and the drain valve open. It took some effort but looking under the caravan afterwards quite a bit of water had been pushed out (next time I'll measure how much). I'd driven back from site approximately 60 miles with the drain open and both taps and shower open in the mid position a couple of weeks earlier.

Applying my (questionable?) logic, draining water from the lowest point in the system (the yellow valve) should be better than trying to blow it out of the highest points in the system. The pressurizing contraptions blow water out of the taps and shower - the highest points. Surely the air will bubble through the water leaving some in the system?

 

[Hutch]

I made a blow through fitting from an old water pump connector, after traveling home with both hot and cold drain valves open and taps in mid position, I then close the drain valves and using the hand pump for my air awning, blow through the pipework hot and cold taps , one at a time.
I was surprised to get about a cup full of water from each tap. It takes about 20 minutes to do. Finally opening the drain valves and blowing out the last of the water. . It keep me happy that's all that counts.

 

[RogerL]

After reading a few threads on this subject I went out and blew down the shower hose in my caravan with the taps closed and the drain valve open. It took some effort but looking under the caravan afterwards quite a bit of water had been pushed out (next time I'll measure how much). I'd driven back from site approximately 60 miles with the drain open and both taps and shower open in the mid position a couple of weeks earlier.

Applying my (questionable?) logic, draining water from the lowest point in the system (the yellow valve) should be better than trying to blow it out of the highest points in the system. The pressurizing contraptions blow water out of the taps and shower - the highest points. Surely the air will bubble through the water leaving some in the system?

I think your logic is correct - it should leave less water in the system by blowing down from the highest point to the lowest.

 

[Beachball]

+1 Yes you do drain it down and then i use to lift the taps and shower and open the drain down tap to make sure there was no water left in also we made sure no rinse in the toilet cassette

 

[otherclive]

I used to put -10 deg screenwash in the flush tank, and pumped an amount through into the cassette. Only about 1 litre into flush.

 

[Buckman]

This is a bit of a "Marmite" issue. Some will insist is absolutely essential to remove every last drop of water, and others will say that's not hecessary.

To my simple mind a bit of water left in a pipe isn't an issue. It can certainly freeze, but as it does so, because it has air all around it can expand into that air (because air can be compressed) The problem arises when a pipe is full of water with both ends "sealed" The water then expands as it freezes, there is no air in the pipe to be compressed as the water expands, so something has to give, be that a pipe or a joint.

Me? I open the yellow dump valve, along with all of the taps, after leaving a site. My theory being that all of the motion of the journey home will ensure any residual water finds its way to the dump valve and out of the system. Over the 20 plus years I have owned motorhomes and caravans I have never suffered a burst pipe or popped joint. So I reckon my theory has some reasonable credibility. Others will just say I have been very lucky for 20 plus years.

Very good advice. However many people forget about the water filter. This holds water and ends up cracking the filter housing when it freezes. At the start of the new season people run water through the pipes and this ends up leaking out the cracked filter and soaking the caravan.

 

[Dustydog]

I used to put -10 deg screenwash in the flush tank, and pumped an amount through into the cassette. Only about 1 litre into flush.

Since 2008 the C250 was supplied with a modification, a secondary drain pipe ensuring all water was removed . The kit was sent to owners foc as a diy fit. Later models were built modified ensuring no fluids remain in the flush tank.

 

[otherclive]

Since 2008 the C250 was supplied with a modification, a secondary drain pipe ensuring all water was removed . The kit was sent to owners foc as a diy fit. Later models were built modified ensuring no fluids remain in the flush tank.

But can you guarantee that the pump is drained too?

 

[Dustydog]

But can you guarantee that the pump is drained too?

That was the sole reason I believe for the modification

Thetford offers customers a free drainage solution for C250 caravan toilets

Following a number of reports of broken pumps on the C250 CWE cassette toilet, Thetford has designed a new drainage solution which prevents the problem and is offering it free to anyone with the toilet model

www.caravantimes.co.uk

 

[Mr Plodd]

Very good advice. However many people forget about the water filter. This holds water and ends up cracking the filter housing when it freezes. At the start of the new season people run water through the pipes and this ends up leaking out the cracked filter and soaking the caravan.

Never had a water filter either in a motorhome or caravan. But yiu are 100% correct in what you say,

 

[Buckman]

Since 2008 the C250 was supplied with a modification, a secondary drain pipe ensuring all water was removed . The kit was sent to owners foc as a diy fit. Later models were built modified ensuring no fluids remain in the flush tank.

I am fairly sure that we have the C250 toiler, but no flush tank as the water comes direct from the onboard tank. So I guess that is a bonus?

 

[otherclive]

That was the sole reason I believe for the modification

Thetford offers customers a free drainage solution for C250 caravan toilets

Following a number of reports of broken pumps on the C250 CWE cassette toilet, Thetford has designed a new drainage solution which prevents the problem and is offering it free to anyone with the toilet model

www.caravantimes.co.uk

Well that one passed me by.

 

[otherclive]

Very good advice. However many people forget about the water filter. This holds water and ends up cracking the filter housing when it freezes. At the start of the new season people run water through the pipes and this ends up leaking out the cracked filter and soaking the caravan.

I always binned the water filters and never had any stomach issues here or overseas, and the bank balance was improved too.

 

[Dustydog]

Well that one passed me by.

Were you feeling flushed😉

 

[Buckman]

I always binned the water filters and never had any stomach issues here or overseas, and the bank balance was improved too.

Except for probably out first 2 - 3 caravans way back in about 2004, we always had the filter removed before purchase. IMHO a waste of money buying filters.

 

[toad a caravan]

I am fairly sure that we have the C250 toiler, but no flush tank as the water comes direct from the onboard tank. So I guess that is a bonus?

I don't have an onboard water tank ..not that flash 😊

 

[Beardy]

After reading a few threads on this subject I went out and blew down the shower hose in my caravan with the taps closed and the drain valve open. It took some effort but looking under the caravan afterwards quite a bit of water had been pushed out (next time I'll measure how much)

Next time was today. 84 mile drive home with the taps open in the mid position and the drain valve open. I caught and measured the water pushed out of the drain valve when I blew down the shower hose ........... 600ml, or a touch over a pint in old money. I have no idea whether that would be enough to cause a problem if it froze in caravan water system but I know for sure that it won't now.

 

[ProfJohnL]

Next time was today. 84 mile drive home with the taps open in the mid position and the drain valve open. I caught and measured the water pushed out of the drain valve when I blew down the shower hose ........... 600ml, or a touch over a pint in old money. I have no idea whether that would be enough to cause a problem if it froze in caravan water system but I know for sure that it won't now.

I can assure you, depending on where the water resided in the system, as little as 10ml in the wrong place freezing can damage valves and seals.

 

[Hutch]

Next time was today. 84 mile drive home with the taps open in the mid position and the drain valve open. I caught and measured the water pushed out of the drain valve when I blew down the shower hose ........... 600ml, or a touch over a pint in old money. I have no idea whether that would be enough to cause a problem if it froze in caravan water system but I know for sure that it won't now.

Think about the internal size of the water pipes. 3/8 th inch. With a few joints holding water , that's where you get them punching apart or splitting when there's an over night freeze. You only need a a few eggcup fulls of water to do damage.
I would rather just blow through the pipes.
Get a hand pump for an air awning and a rubber clamp for the taps to the pump. A few strokes and you will expele most water. . Remove a water filter if you have one.
All fluid measures in "old money".