Alde 3020 air cushion?

[JezzerB]

Our new caravan comes with alde heat. Very impressed so far but the booklet is very confusing. Diagram of the unit all numbered but no key to what any of it is for example. Then there is the air cushion.

It says it needs (the aircushion) renewing every ten day s by opening the safety /drain valve for a few seconds. Is that the yellow underseat flap that drains all the water. ? We drain down our system for driving. Is that the same or does it need opening in use and surely if in use the pump kicks in and fills again. Hence no cushion? As you can tell i am very confused!!!!

 

[JTQ]

Because you drain down for travelling in itself will ensure that a small amount of air will be "trapped" in the crown of the boiler on refilling. So in your case, IMO no need to do anything else unless you don't move for a couple of weeks.

I suspect it serves to add a bit of compliance to accommodate the expansion between temperature changes of the water, and smooth the tap/pump interaction.
I find, with the system shut off there is always a bit of retained pressure and compliance in that we can, with everything shut down still run quite a bit of water from a tap. I take this meaning the required trapped air is still there even a week in use.

Edit: With our installations being in plastic tube so offering a bit of compliance an installation made in metal tubing does not have, would protect the boiler and system from any expansion issues, even if reinstating the air buffer was overlooked.
Ring Alde UK if concerned, their technical team always readily and friendly offer help.

 

[JezzerB]

Thank you; You've explained it much better than the Alde instruction booklet-as you say if we are away for a longer stretch I''ll just open the valve a few seconds as it states-every 10 days they recommend!

 

[Buckman]

Thank you; You've explained it much better than the Alde instruction booklet-as you say if we are away for a longer stretch I''ll just open the valve a few seconds as it states-every 10 days they recommend!

Actually I think the correct word is bleeding the system at the highest point which is normally the radiator in the bathroom. Probably need to do it a couple of times. Best is to drop the nose of the caravan while out for the day and to leave heating on so that fluid circulates. Bleed on your return.

 

[JezzerB]

Don't think it is bleeding -it's the opposite-the system needs a bit of air in it via the safety/water release valve ie the yellow one under the seat usually by the boiler. Just need to open it up if you are in there longer than 10 days-as above if I release the water every trip unless we are away on a longer hols then we won't need to do it.
From what I understand!

 

[Buckman]

Don't think it is bleeding -it's the opposite-the system needs a bit of air in it via the safety/water release valve ie the yellow one under the seat usually by the boiler. Just need to open it up if you are in there longer than 10 days-as above if I release the water every trip unless we are away on a longer hols then we won't need to do it.
From what I understand!

We have had the ALDE 3020 system for the past 4 years and have never come across this air cushion being mentioned. I have done a search on the pdf of the 3020 and found the reference to the air cushion which states that it is there to compensate for pressure surges however we have the Whale surge control fitted in ours.
May apply to a caravan on a seasonal site, but we have never bothered with it as the longest we stay on any one site is about 2 weeks. We have never had any issue with surges as we always drain the cylinder when leaving a site.

 

[JezzerB]

Thank you-I did think that too tbh-we don't often do more than 2 weeks ourselves- and quite often do shorter stints in one hol where we would always drain down before moving anyway!

 

[Buckman]

Thank you-I did think that too tbh-we don't often do more than 2 weeks ourselves- and quite often do shorter stints in one hol where we would always drain down before moving anyway!

Then no need to worry about any air cushion. LOL! :cheer: I agree that manuals can be more confusing as a lot gets lost in translation.