Advice needed on old Alde hot water system please...

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Jun 16, 2020
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Bleed valves will look very similar to standard domestic bleed valves. Try following to single pipe circuit heating circuit around the van, you should find up to half a dozen.

Filling is fundamentally the same as filling any heating system and in some ways easier than in a domestic situation as there is only 1 large pipe as opposed to many, possibly down to 8 mm in the domestic. In all cases there is a possibility of an air lock. Alde try to avoid this and speed up the process by using there filler pump, but these are about £400!

I do know of people who have successfully made their own with a submersible pump and force the fluid through the flow pipe.

When I did it on a modern Alde system, I filled it very slowly , not into the header tank but in to the flow pipe by gravity. Then left the pump running at 5 for a short while. Not a lot of bleeding to be done. Which should be done straight after filling then again after running at heat.

It did take me about 4 hours to change the fluid, not cost effective if I was doing it for a living, but that is not the case.

John
 
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Jul 27, 2020
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Thanks John. I see quite a few wide bore pipes at the back of the boiler, no idea which is the one I hear referred to as the "flow" pipe. Alde said something about the flow pipe too.

I had this reply from them:

"Technical support for the 292X-series was discontinued many years ago now, and no spare parts are available for them either.

The 2923-2928 models service manual is available. All 292X-series are very similar.

http://www.moosewerks.co.uk/downloads/v8uvu8b4/alde_2923-2928_service.pdf

The cylinder in your photo is the hot water heater module. This is separate to the central heating circuit.

The central heating system is open vented from the plastic expansion tank in the boiler. There should also be bleed points fitted elsewhere, on radiators, towel rails, etc.

We would probably use a suction pump to empty the bad glycol fluid in the boiler, then disconnect the top duct (flow) of the boiler that comes from the expansion tank.

We'd attach a push pump to the top heating pipe leading to the radiators, and a hose to the top duct that comes from the expansion tank. The hose we'd lead to a large bucket.

This would allow us to push water through to flush the system, then push the new glycol fluid in, pushing the water out.

Best regards,

Joakim Johansson
Customer Service Advisor
Alde International (UK) Ltd"


I am ashamed to say I am still none the wiser really. I guess I need to go find me a bleed valve somewhere and then I might start making headway. If i find several, I could try the manual's guidance.... fill the expansion tank, run for a while, jack front and bleed, jack back and bleed, repeat until no more air. Lets see if I can find any valves....
 
Jul 27, 2020
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Sorted!

I found a rusty old 12v submersible whale pump in a cupboard. AFter cleaning it up i found it still worked, so i used some pvc tape and old rubber plumbing bits and bobs to fashion a pipe which would fit snugly onto the drain pipe for the heating system under the caravan. I then drained the system, put pump on, and pushed fresh water in to see how much it took (to reach min level on expansion tank). I did that a few times to get a good calculation on how much fluid it needed. It was about 10.5 to 11 litres. That gave a nice flush (several in fact). I marked the bucket (after draining it each time), then mixed up a nice fresh mix of 40-50% G40 to de-ionised water. I shoved it in with the pump running off a 12v wall wart. I watched for the level hitting just above min, then quickly pulled the pipe off and plugged the bung in. Its all working very nicely! No air locks :)

Thanks for the help here everyone
 
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Jul 27, 2020
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Oh, and PS... I am running a blue Calor gas bottle at the moment, as it has a blue regulator on the gas pipe into the caravan. I want to change that to orange (propane) for better frost protection. Am I right in thinking I need to change the regulator thingie to a red propane one? I assume it's a good idea to switch to orange bottles?
thanks
 
Nov 11, 2009
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Oh, and PS... I am running a blue Calor gas bottle at the moment, as it has a blue regulator on the gas pipe into the caravan. I want to change that to orange (propane) for better frost protection. Am I right in thinking I need to change the regulator thingie to a red propane one? I assume it's a good idea to switch to orange bottles?
thanks
Yes as the weather gets cooler butane Won’t work and propane is required. I keep mine on propane all year after being pitched on Dartmoor one October and no gas appliance would work in the early morning.
 
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Jun 16, 2020
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Thanks John. I see quite a few wide bore pipes at the back of the boiler, no idea which is the one I hear referred to as the "flow" pipe. Alde said something about the flow pipe too.
The flow will always be the pipe that comes from the boiler at the highest point, return is below this.

Not that that matters. It sounds like your method has worked very well.

Have you found any bleed valves? Have you had a test run yet?

John
 
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Jul 27, 2020
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Propane it is, thanks! So I just swap the regulator over from blue to red, then enjoy the orange stuff?! Sounds easy enough for me!

Dartmoor - we are so in love with this thing now, when we can afford it I will get it jacked up and replace the two axles and brakes and hitch, then it's ready for the road. That was never the intention and may never happen, but it's such a beautiful thing now (with a lovely shower and heating system now working!) that we may just find it a bit too good for the dragon in law :D

I found one bleed valve, I did use it but I think the radiator did the trick. in the shower there's a radiator (like a house one) so the bleed valve at the gtop of that is higher than any other point except expansion tank. I released a bit from there and everywhere got hot nicely. I found another breather today when I discovered an outdoor boot cupboard (my guess as to its purpose!) and blow me if there isn't a hot water pipe running around it! and on it..... a breather! Nice to know for the future. I will grab some pics when I remember and stick them on here.

The only thing I need for it to be properly complete is a window. The rear side one by the single bed/dinette thing, it is the one which was broken for years and eventually blew off. I have managed to tape it up well enough to prevent rain coming in, but I will replace it when I can. They cost a fortune new so I am waiting for a Bessacarr Cameo 550GL to come up on fleabay and hope to get a used window in good nick some time.

Thanks again folks
 
Jul 27, 2020
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PS yes JC the heating is working very nicely. On 1KW it has a mild warmth all round (probably all my visitors will need most of the time). On 2KW the rads get almost too hot to touch. On gas you can cook your eggs on the rads. :D
 
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Jul 27, 2020
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Question re Butane/Propane. The caravan currently has a blue regulator attached for the fitting to gas bottle. I notice it says 28mbar on it. But the old propane one I have here in the shed says 37mbar. I looked for new ones and they all seem to be 37mbar. Am I ok to use that? Don't want to make a boo-boo after all this work and blow a pipe or something! thanks
 

Damian

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Mar 14, 2005
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Yes it is perfectly OK to use the 37mb regulator with Propane.

All caravan equipment is rated to run on either Butane at 28mb or propane at 37mb.

Newer vans have a bulkhead mounted regulator which supplies 30mb for both gases, just a change of pigtail to suit whichever gas is being used.
 
Mar 14, 2005
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Question re Butane/Propane. The caravan currently has a blue regulator attached for the fitting to gas bottle. I notice it says 28mbar on it. But the old propane one I have here in the shed says 37mbar. I looked for new ones and they all seem to be 37mbar. Am I ok to use that? Don't want to make a boo-boo after all this work and blow a pipe or something! thanks
28mBar Butane and 37mBar Propane is standard for UK LPG systems prior to 2003, when the standard changed to a common 30mBar pressure for both Butane and Propane.

Your system seems to be designed to the old 28/37mBar standard and you should continue to be absolutely fine.

If you are interested in why you might need to change gas types read on...

Butane and Propane have very similar burning and heating characteristics which is why we can usually use either product in a caravan.

Both gases can be liquified by either cooling and/or compressing the gas. This enables it to be stored in the cylinders we know. The cylinders contain liquified gas and some gas vapour under pressure.

The actual pressure in the cylinder is dependant on the temperature of the cylinder. If liquified butane is cooler than about 0C it will not vapourise, so the pressure in the cylinder will reduce to normal air pressure, and thus it will not come out of the cylinder. This is colloquially known as "freezing" in fact its just stopped boiling.

By comparison Propane needs to fall to -42C before it stops boiling for the same reasons. But its this much lower boiling point that makes it more suitable for winter use.

But there is another factor that needs to be considered. As we draw gas from a cylinder, we actually reduce the pressure in the cylinder. The reduced pressure encourages the liquified gas to boil, and it will provided it is warm enough. However when a liquid boils it actually needs heat energy to vapourise the liquid, and the gas gets this energy from the mass of the liquid, and consequently the liquid cools down a bit. If the ambient air on the outside of the cylinder cannot replenish that heat, eventually the cylinder will cool too far and the gas pressure will drop so low its unusable.

That is why we have to give some temperature margin when recommending Butane. And I always suggest that the lowest practical ambient temperature for Butane in a caravan is +5C. If you are operating below that ambient temperature Butane gas is not going to be reliable.

I cannot vouch for gas supplies in other parts of the world, but in the UK and the EU, both Butane and Propane cylinders should be perfectly safe and are manufactured to very high margins of safety.
 
Jul 27, 2020
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Just had a thought.... drinking water. We have visitors coming to stay in the old girl for a few days! I bought a few 5L bottled waters from Tesco as it suddenly occurred to me that the onboard tank on this caravan has been sat doing nothing for night on a decade! I assume it's not wise to drink from it, although looking at it under the seats, I can't see a single sign of any dirt or algae etc, it's clear transluscent plastic with no watermarks or anything, I could be fooled into thinking it was new! I am wondering what the general rules are on drinking from this sort of age tank? We have a nice water supply here for drinking water so it would be nice to use the tap water. Someone told me you can buy tablets to sterilise containers, could anyone recommend any or at least if they work and make containers safe to drink from?
thanks
 

Parksy

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Nov 12, 2009
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Just had a thought.... drinking water. We have visitors coming to stay in the old girl for a few days! I bought a few 5L bottled waters from Tesco as it suddenly occurred to me that the onboard tank on this caravan has been sat doing nothing for night on a decade! I assume it's not wise to drink from it, although looking at it under the seats, I can't see a single sign of any dirt or algae etc, it's clear transluscent plastic with no watermarks or anything, I could be fooled into thinking it was new! I am wondering what the general rules are on drinking from this sort of age tank? We have a nice water supply here for drinking water so it would be nice to use the tap water. Someone told me you can buy tablets to sterilise containers, could anyone recommend any or at least if they work and make containers safe to drink from?
thanks
Some members here will tell you that they always use the caravan water system for drinking with no ill effects.
The system can be cleaned with Puricleanse sterilising tablets or Milton
sterilising fluid, used for babies feeding bottles etc.
Milton will attack stainless steel boiler parts of left in the system for longer than 30 minutes.
Personally speaking, having seen the foul black sludge that can line the inside of plastic cfaravan water pipework we always have bottles of drinking water available.
We use this for beverages or for drinking, the bottles can be replenished from the site drinking water supply if the site water tastes ok.
I sterilise the water system in our caravan twice per year and drain the system when we leave a site, but despite the apparent cleanliness of the internal water tank and the Aquaroll I still wouldn't drink from the caravan taps.
Others will tell you that it's fine, they do it all the time.
Do you know how clean the plastic pipes are inside?
The choice is yours 🤢
 
Nov 6, 2005
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Given the tank has stood unused for a decade, I'd clean it with Milton or Puriclean - it's a very different situation to those who use their caravans regularly and don't need to clean the system.
 
Jun 16, 2020
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When we has an onboard tank I had to clean it as it was awful and disgusting. Out of site and out of mind. In a domestic, old fashioned system, all hot and cold water is fed from a storage tank except for 1, which should have been used for drinking. These tanks were often open to the elements and many had dead pigeons in them.

I do not miss an onboard tank for hygiene reasons.

We puriclean our system once a year and use bottled water for drinking or, like Parksy, fill bottles from the site supply. But often they seem over chlorinated and make a lousy cup of tea,

Bought bottled just yesterday, Morrison’s 17 pence for 2 litres. But if you can stretch to Evian!

John
 
Nov 11, 2009
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I use Puriclens once a year. Tend to use site water for drinking. We have a 10 litre water container that generally gets used for topping up the aqua roll. Rarely if ever buy water in plastic bottles on environmental grounds, cost being irrelevant.
 
Jun 20, 2005
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We clean all pipes and on broad tank about four times a year with puricleanse or Milton. We do drink the fresh water from our taps 12 years on we are still here!
a word of warning. Do not leave Milton in the system longer than 20 minutes. It can corrode stainless steel parts like your Truma water heater.
 
Jul 27, 2020
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Thanks everyone. Well we have good tap water here, so it's just a question of whether I have dirt in the pipes and as mentioned it probably isn't spotless after sitting idle for so long! I will have to find some of this puricleanse stuff, thanks
 
Jul 27, 2020
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A brief update/question - the renovation went well and we have family coming to stay in the Bessacarr next week. I am considering upgrading the water pump. It currently has the original "Made in USA" (those were the days!) Shurflo 6.4l per min water pump. The flow from taps is pretty poor, seems poorer than I would expect and I am used to caravans so I know the pressure doesn't compare to mains/house taps. However I am thinking of replacing the pump and I see there's a choice. There's the standard Shurflo which is also 6.4 litres per min, but there's a Trailking model which says 10.6l per min. Has anyone tried these in caravans and had success? I know there's a risk of leaks but I might give it a go if others have used them successfully.
Thanks
 

Damian

Moderator
Mar 14, 2005
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I personally always replace pumps with the Trailking as they are better pumps, and so far no problems reported by customers.
 

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