Truma dump valve again (1 Viewer)

[Fletton]

Right....
Just been and looked at dump-valve..
The top T hadn't moved ... but the bottom button was out!..

I've just manually clicked the T open and and reset a few times...

BTW mine is tight up in the outside services locker... and would be a right faff to remove...

 

[Fletton]

Reading further up the page - diagram - it mentions "pressure relief valve"...

Do you think the heater is "boiling" the water... as opposed to cold temperature dumping it?...

I say this because the T hadn't moved..

Thoughts

 

[Duck Truck]

The valve looks to be nowhere near the boiler
and my guess is the heat from the boiler doesn't circulate near enough to keep the valve warm.

On our other van the cold water pump was sited nowhere near a heater pipe and consequently froze and cracked over night. After replacing it I extended the truma ducting so that it provided a trickle of heat near the pump and that worked fine

^{_{Subscribers  do not see these advertisements}}

 

[Phaeton]

Well it certainly did... any ideas welcome ...

Edit: Is there any way to test valve for faults?

Before faults, consider your set up - which valve, whether connected to the power circuit and location relative to tank?
The thermometer you pictured suggested that the air temperature was low enough to trigger, so if the valve wasn't really close to the tank (and as they are generally below it that doesn't help) and isn't electrically connected to recognise the tank is on, it will open.
Mine (old and tank off) triggered yesterday despite a small oil rad right outside the tank door with a mesh grill - clearly the radiator thermostat was set too low relative to the valves setting.

 

[Lenny HB]

I agree with @kev1 to me I would say it has been incorrectly installed it should be close to the boiler with a free flow of air from the boiler. In a remote location it should have the heating collar fitted.
Looking at the installation probably nothing wrong with the valve. Easy to check as you could monitor the temp with the locker door open.

 

[Zigisla]

The "T" on top is to manually dump the water from the boiler. When it automatically goes, just the button pops out. Defo seems that although the water was hot in the boiler, because the v/v is near the outside, the water in the pipes was cold enough to set it off. When I manually release the v/v, I immediately turn the "T" back, then all I have to do after the water has gone is to re-set the button.

^{_{Subscribers  do not see these advertisements}}

 

[jezport]

Give Truma call.
AFAIK If the dump valve is fitted away from the boiler in a double floor or locker it should have the electrical connections that are used to keep the valve shut when the boiler is turned on.

 

[Duck Truck]

I would be extending the heating duct to cover this area or fitting a grill to allow warm air to circulate in this area

 

[Fletton]

Well just had seat up looking at Truma... and plumbing etc... I cannot see where the back of the DV is - its buried tween floors and gubbins... however, there is no lead connected to the Dump Valve plug/socket on the boiler unit...

So my guess is as you say... too far away - and in a potential cold spot..

Time to ponder a remedy

Edit: @jezport --- I think I may call them to see what's what

^{_{Subscribers  do not see these advertisements}}

 

[jezport]

Well just had seat up looking at Truma... and plumbing etc... I cannot see where the back of the DV is - its buried tween floors and gubbins... however, there is no lead connected to the Dump Valve plug/socket on the boiler unit...

So my guess is as you say... too far away - and in a potential cold spot..

I cant see how it would work if its in a remote position away from the boiler without having the electrical connections.

 

[Vanman]

If it wasn't a big company like Knaus I'd be thinking it's a design issue of the MH.

I suppose you could swing the temperature calculation back some way with a bit of old fashioned lagging around the valve.

 

[Fletton]

If it wasn't a big company like Knaus I'd be thinking it's a design issue of the MH.

I suppose you could swing the temperature calculation back some way with a bit of old fashioned lagging around the valve.

I was thinking of getting a very small dog (or perhaps a cat)... And popping it in the locker of an evening.... Surely that would work

Failing that .... Either lagging as suggested and/or I could just place a wedge (stick) tween button and outer skin for now... If the water and heating remain on... Surely there'd be no chance of any pipe work freezing... Would there?

^{_{Subscribers  do not see these advertisements}}

 

[Vanman]

I was thinking of getting a very small dog (or perhaps a cat)... And popping it in the locker of an evening.... Surely that would work

Failing that .... Either lagging as suggested and/or I could just place a wedge (stick) tween button and outer skin for now... If the water and heating remain on... Surely there'd be no chance of any pipe work freezing... Would there?

Well I think you need to establish that for sure. It certainly seems that the 'remote' positioning of the valve is the problem, but I think that I'd have a min/max thermometer in next to the boiler for a night or two just to check there really was no chance of it freezing, maybe your van holds its heat so well that the boiler stays off for extended periods, or maybe there's a problem we don't know about ... in any case I'd recommend a dog AND a cat in the locker (maybe a Jack Russell and a stray) they would have hours of heat building fun with each other

 

[Duck Truck]

I think Vans last line is the answer

 

[Fletton]

Well .... After looking at the plumbing diagram on Truma site an thinking on...

This is why I think said dump occurred..

Although I had left hot water on 24/7 ... For the last two days of cold spells I had not actually drawn any hot water from the system - so any water in the pipes near DV had "chilled"... (I'd stayed over in bricks and mortar and had used facilities there ) .... And last night I cooked and left the pots.. Whereas If I'd not been so lazy (sloshed) and washed up... The said pipes (and DV) would have probs been warmed enough to see the night through... I think this is why it's "random"... Perhaps!..

That said... The ideal scenario (given setup) would be for the DV area to receive some residual heat from heating system.. When it's on etc.

John T

^{_{Subscribers  do not see these advertisements}}

 

[Duck Truck]

I think you are bang on.
A real design fault if no hot air circulates around the dump valve itself

 

[Fletton]

I think you are bang on.
A real design fault if no hot air circulates around the dump valve itself

I've set an alarm to draw some hot water every hr ... from 23:00 to 07:00... NOT!!!
I can always snooze during the day!..
and sometimes do

EDIT:: Lagged

Ps got genny running... but don't panick Mr Manering... I'm the only soul here

 

[Duck Truck]

Hi fletton
to ensure we knew the temp near the pump
I bought from Lidl for about £3.99 an external temp gauge
that has a frost alarm. Runs on 1 AA battery.
The sensor hangs on its cable down near the Pump / dump valve
The temperature near the pump is shown on an LEd display in the van. If the temp drops to near freezing it sounds an audible alarm. it worked brilliantly

So that if during the night your gas runs out and the heater shuts down. it wakes you up
However that's usually after Sue has kicked me out of bed into the snow to change the gas bottle

^{_{Subscribers  do not see these advertisements}}

 

[Duck Truck]

Look for a junction in the truma ducting and run a spur off with a trickle valve on the end
Cost me about £20 to do
I ran one near the pump and an extension into the cavity wall behind the shower where all the
bathroom water pipes ran. Stopped any further freezing

 

[sdc77]

@kev1 great idea.
We have the manual dump valve and use the van all year so gladly don't suffer these issues

 

[Larrynwin]

As mentioned earlier a diversion of warm air to the area would work .
All lockers and double floor areas in our mhome receive blown air so no risk from frost .
I set stat at 10degs when risk of frost if not drained down.

^{_{Subscribers  do not see these advertisements}}

 

[Andrew gill151]

Reading all these replies, think it may be the positioning of the valve on the Knaus, in the last 3 days has dumped water out 3 times.
will be leaving heating on for the next few days.

 

[Lenny HB]

Probably worth splashing out the 40 quid for the heater unit for the valve.

 

[Fletton]

Well after some investigstion today... I discover the locker is heated...
However, it appears to only be effective with fan on high.. ECO seems to be naff...

Here is the warm air vent... I think I may pipe it nearer to the DV

Edit: just been out and felt it on ECO setting... and it is streaming warm air...
I guess I would need to raise temp in Moho. (Overnight) ... in order to keep said locker from becoming too cold...

^{_{Subscribers  do not see these advertisements}}

 

[daveandsan]

That's a bad design, my dump valve is right next to the heater.

 

[Fletton]

That's a bad design, my dump valve is right next to the heater.

It's Knaus's - all in one place - services locker setup.... but it seems it may be flawed slightly....

Else... I haven't RTFM .... but it is in German !..

 

[Blossom]

I am just glad you didn't have to get a dog or cat to use in the locker

^{_{Subscribers  do not see these advertisements}}

 

[Fletton]

Ferkin thing dumped again early this morn...
Have had to wedge shut to save last of water....
I have sussed from another Knaus owner over on FB that I am missing an elbow to point warm air at DV...

OP's warm air vent....

 

[Lenny HB]

I wouldn't think the elbow would make any difference in such a small area.
I am still surprised it dumps, we have never had ours dump when in the van and we never run heating or hot water at night. Normally enough latent heat in the van from the heating being on in the evening and the van normally stays above 10 deg.
I would still be inclined to run a test on the valve just in case you have a faulty one. German vans are normally fine in skiing conditions, in those conditions you do have to run the heating 24/7, but normal use shouldn't need to.

You haven't said where you are and what the minimum night time temperatures are, if it's minus 10 all night you would need the heating on but even the smallest heating vent into that small area would keep it above 3 deg.

 

[jezport]

Unless you keep the van heating hotter than usual it will dump so you will waste lots of gas. It should have the electrical connection holding it closed if the boiler is on. Its the wrong type of valve for the remote location. It should have the electrical connections.

^{_{Subscribers  do not see these advertisements}}