heater burst a pipe (1 Viewer)

[mark49]

Mitzimad,The yellow lever was in upright position when this happened,I moved it horizontally later when I was trying to workout it’s use

 

[hilldweller]

Mitzimad,The yellow lever was in upright position when this happened,I moved it horizontally later when I was trying to workout it’s use

Interesting...........

I can't be sure what would happen but the high pressure cold water is pumping into the bottom of the boiler and also to the top hot outlet at the same time. I guess that could cause the hot tap to run warm, not hot. Maybe it opened the relief valve and allowed hot water on to the plastic pipe which probably could not handle hot plus pressure at the same time.

 

[Misterg]

The yellow lever was in upright position when this happened,I moved it horizontally later when I was trying to workout it’s use

Aha! The valve is open when it is upright - I did check your photo to make sure it was closed

As soon as the pipe burst, all the water would come out through the open valve. Probably all that has happened is that the clear PVC pipe has given up the ghost (actually it had an aneurysm!) as it was subject to the full water pressure through the open blue valve and at the same time was picking up a bit of heat from the boiler. There is *probably* nothing else wrong.

(Edit: Like wot @mitzimad said)

(The clear pipe is not designed to hold pressure and will swell and burst, especially if it is warmed at the same time.)

there is nothing in the blue valve that is temperature sensing

Not really relevant to the thread, but I speculate that it has a bi-metal disc in it that flips to drain the water when it gets cold - it is described as part of the frost protection for our boiler, and that's one way I could see it working. It *is* just speculation though and could equally just be weasel words in the manual.

Edit: I think the red elbow needs a pipe to outside because it can dribble a a bit when you fill the boiler - the check valve is a loose ball, not spring loaded.

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[pappajohn]

Thank you, I hate being wrong but I'm always willing to learn.

But I'm puzzled, if it is just letting air in then in reality it does not need a pipe to the outside. The other end of the that looped pipe will be blocked by the manual dump valve. So what popped the pipe open ?

AH!! The dump valve could be open, naturally it would dump nothing but it would mean both sides of the red valve would have equal pressure on it, for what that's worth ???


This confirms "breather" not pressure relief:
https://www.caravanaccessoryshop.co...astore-elbow-push-fit-with-breather-pipe/3248

Posting links has already been condemned Brian.
I posted a link to the same item which listed it as a PRV and another to a blue and yellow dump valve......but Truma decided to rename them.

Regardless of whatever each item is called, whoever fitted that pipe wants their arse kicked.

Anyway, I've said my piece... I'm out

 

[tonyidle]

A problem Tony, the pipe has burst above floor.
So yes, one half to the dump valve will be OK if cut underneath, which is good looking at all that crap slapped around the pipe as it enters the floor, but it still needs renewing to the PRV.

Yes - saw that & assumed the OP would fix it anyway. I was concentrating more on correcting the obvious (and weird) plumbing under the van . And I was wrong about which valve did what.

 

[hilldweller]

Edit: I think the red elbow needs a pipe to outside because it can dribble a a bit when you fill the boiler - the check valve is a loose ball, not spring loaded.

More puzzles for me. Like the OP picture shows, ours has the vent pipe pointing upwards. So that ball must float to seal the vent ??? Long term, hard water a possible point of failure.

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[HandyAndy]

Wow four pages of bickering over this simple fault..
OP needs to listen to PapaJohn and forget everything else.

Some pillock of a previous owner has probably looked under the van at some point, seen the dangling pipe, seen the drain oulet and gone in his head "oh this has come off" put the two back together and proceeded to snot the hell out of it without a single thought about what either does.
So.... To fix
Cut the pipe under the vehicle so you have two open ends, repair the burst section of hose, refill and re-test the system. then observe what happens. It may have been just expansion or it may be an overheat scenario from a thermostat failure. you won't know without fixing the plumbing first and TEST IT

 

[pwilmo]

Hi there you're lucky I am an expert on this matter.
What you are showing in your original photo is not a pressure releif valve, it is in fact a vent valve to allow air into the top of the boiler when draining down ... if you have no air inlet above the upper water level you create a vacuum which would hold the water up preventing drain down of the boiler.
Check out my page on this link
https://comparing4u.wordpress.com/2012/10/23/motorhome-truma-leak/
The clear tube attached should be open ended and unblocked (maybe someone has seen the tube clogged and bent up , and decided to burst it open at the easiest place )

 

[Enword]

This thread reminded me of this,
We had a sink waste hose that went straight in to a waste hog on one of our race vans, one day I'd fired up the eberspacher to give it a workout as your suppose to & when back into the workshop a while later I came out to switch it off & there was loads of smoke & a strong burning smell, didn't panic MUCH, the van had been for its MOT a few day's before & for some reason they had twisted the flex hose for the sink over & around the exhaust of the eberspacher!!

Similar could have happened to your van's boiler hose at some point, someone thinking their being helpful

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[pwilmo]

Nope, definitely not, this clear hose in these pictures has not been melted or heat damage, someone has taken the easy way of unblocking the air tube ... looks like with a knife to open it up.

 

[mark49]

Just a quick update on this problem, I replaced the “hot water joint” I think it was named,bought a replacement 100 yards away from were the M H is stored, how lucky is that?it comes as a kit complete with the clear tube£22 ,refilled and tried the system on heating only and it worked a treat, never had the chance to try it on water and heat which it was on when the burst happened.again thanks to all the input.