Truma Auto dump valve (1 Viewer)

[Jerrymjj]

I've seen a few references to this auto dump valve in posts on here. Could someone explain what it is please and what I have to do to avoid losing the contents of our hot water tank?
Many thanks, Jerry

 

[GJH]

It's a small, red valve fitted in addition to the manual dump lever. Not all vans have one - our Autoquest didn't but the Burstner does.

It opens when the temperature drops to 4 deg C and is reset by lifting the top part - but it can not be reset (i.e. clicks and stays shut) until the temperature around it reaches 8 deg C.

If I am refilling at home after the van hasn't been used for a while and the valve has opened but temp is still not up to 8 deg I use a hot air blower on it gently for a few minutes to raise the local temperature round it.

If cold weather is forecast we keep the water heater on at the 40 deg setting.

 

[Techno]

Yes exactly as Graham says.
Many folk use a clothes peg around the red plunger to prevent it dumping.
I personally use a slotted piece of plastic trunking lid to secure mine

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[Jerrymjj]

Autodump valve

We've just got an Autotrail Tracker SE, 2006, and I can't seen one anywhere. Your photo was enormously helpful. So the moral is, don't keep water on board in the tank if the temperature is likely to drop below 4 degrees C?

 

[davejen]

It should be part of or very near the water heater, have you located that?, secondly yes, below 4c the water can freeze and cause a lot of expensive damage!
Cheers, Dave:thumb:

 

[wasp]

I have changed a couple of these for people and this one supersedes the electric one

it has a manual reset button on:thumb::thumb::thumb:

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[Jerrymjj]

Will all vans have one? I have a Truma hot water system. I'll have to look tomorrow.

 

[Allanm]

Ours has one, just like the image in Wasps post. We have heating set to 10degrees C when we aren't using the van, so frost stat stays warm and doesn't dump the water. You can buy a heater that goes in the frost stat that enables you to fill the system when it's below 3degrees C without using a clothes peg etc. the peg is cheaper!

 

[TheBig1]

the theory is to prevent expensive damage being done to the boiler if the water in it freezes. as we all know the freezing point of water is 0degrees so dumping the water at 4 degrees is a bit premature. plus it would need to be below zero to freeze inside an insulated motorhome

freezing and damage does happen, dont get me wrong. but if you are sensible you can still use the van and have water in it when its pretty cold outside.

personally i dump the water after every trip to make sure it doesnt go stale. i refill when the van is used and that use keeps the inside of the van above freezing. people can worry too much about such things

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[MikeD]

I've seen a few references to this auto dump valve in posts on here. Could someone explain what it is please and what I have to do to avoid losing the contents of our hot water tank?
Many thanks, Jerry

I doubt that your Autotrail has a automatic dump valve on the boiler.

Our 2012 tracker has a manual only drain valve situated near the boiler. The manuals given with the motorhome speak of a automatic version.

But Autotrail told me it is not fitted.

 

[sdc77]

Ours has the manual valve... But the vans left on EHU on the drive when we're not using it with heating set very low (1/4 tank if water) so we don't drain it and it's, always ready to go.

 

[GJH]

As a personal preference I would not use a peg or other device to stop the auto valve from operating as, if damage were to occur, it would invalidate any warranty and probably be expensive to fix. We drain down at home (it doesn't take long to refill) and, as said above, keep the heating on low when away.

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[JeanLuc]

I have fashioned a clip-in retainer for the auto-dump valve. I would never leave it in situ, but it is useful when filling up at home when the temperature is low and I leave it on when travelling if it's cold. I created the 'clip' having experienced a few winter journeys when, having warmed the dump-valve and filled at home, we arrived at a CS or wild spot to find the valve had opened during the journey and the water tank was almost empty.

 

[Pezmc]

Sorry to necropost, but does anyone know if the auto dump valve is also supposed to dump your entire water tank?

Our Truma is downstream from the water tank (which is under the rear seats), and when it's set to empty the Truma, the water pressure from the leaking water pulls water through the pump (even when off), slowly emptying the entire tank. Very frustrating when it's winter, particularly given the water is inside and perfectly usable for the sinks!

 

[IRHP]

Sorry to necropost, but does anyone know if the auto dump valve is also supposed to dump your entire water tank?

Our Truma is downstream from the water tank (which is under the rear seats), and when it's set to empty the Truma, the water pressure from the leaking water pulls water through the pump (even when off), slowly emptying the entire tank. Very frustrating when it's winter, particularly given the water is inside and perfectly usable for the sinks!

Mine will only empty the water in the boiler not the main tank unless the pump is on.

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[leann53]

Yes exactly as Graham says.
Many folk use a clothes peg around the red plunger to prevent it dumping.
I personally use a slotted piece of plastic trunking lid to secure mine

I have a problem with one of these. Tried to fill up and water was being dumed from an outlet pipe on front of rear axle. So disconnected and joined up the 2 pipes and yet I am still dumping water